Five Equipment Adjustments to Improve Weld Quality
Regardless of your skill level, you need to make sure that the equipment you use, works as hard as you do. Consider these components of your welding system to help weld conistency. Could it be time to take a good look at your equipment? Read our article published in the November issue of Fabricating & Metalworking.
MIG Welding FAQ: Best Practices for MIG Success
MIG Welding FAQ: Best Practices for MIG Success
Estimated reading time: 6 minutes
MIG is the most frequently used welding process in general manufacturing and fabrication, thanks to its ease of use, versatility, and productivity benefits.
While MIG is widely used, some operations may still run into issues that require troubleshooting. Understanding the basics of MIG welding and following best practices for operator technique as well as gas and consumable selection can help optimize results with the process.
Q: What are the main advantages of MIG welding?
MIG offers productivity benefits when compared to some other welding processes such as TIG and Stick, thanks to its higher travel speeds and deposition rates. MIG is also considered easier for new welders to learn, so it can be a good option for operations that struggle to find skilled welders.
MIG could be utilized with either solid filler wires or tubular wires such as Metal Cored and when used with Flux Cored wires it is referred to as Flux Cored welding. Tubular wires in general can be run at higher speeds and deposit more weld metal, so they even offer higher productivity gains than Solid wires.
Q: What are the differences between MIG and TIG welding?
There are many factors to consider when choosing the right welding process for your application. These include base material type and thickness, weld appearance requirements, productivity requirements, the welding environment and available skilled labor.
TIG welding is generally used in niche applications, such as those that require high-precision welds or extremely high aesthetic quality. TIG is frequently used with special-grade materials like titanium or stainless steel. In comparison, MIG can be used in higher production applications where increased throughput is important, and it’s a good option for a wide variety of metals.
A typical travel speed in TIG welding is 4-6 inches per minute. With MIG welding, travel speeds are much higher; 6 inches per minute are considered slow, and 15 to 20 inches per minute are common. Deposition rates are also much higher with MIG welding.
Regarding training, TIG is considered the most difficult welding process to learn and master since it uses both hands. An operator may take a few months to become proficient in TIG, while a new welder could be proficient in MIG within a week or two.
Q: What is the right shielding gas for MIG welding?
Shielding gas plays an important role in determining weld penetration profiles, arc stability, mechanical properties of the finished weld, the transfer process you use and more.
The filler metal manufacturer often provides shielding gas recommendations for the type of wire being used, so it’s a good idea to first consult the wire specification sheet.
When using flux-cored wire, 100% CO2 or an 80/20 Argon/CO2 mix are common choices. When it comes to solid wire or metal-cored wire, the right gas is dependent on the transfer mode being used. A short-circuit transfer mode works with 100% CO2 gas in most cases but can still run on mixed gas. While using a pulse or spray transfer, a higher Argon content is needed, and an 80/20 Argon/CO2 is the right choice.
The base material also plays a role in choosing the right gas. Aluminum requires 100% argon, while stainless steel requires at least 98% argon.
Q: Which is better: a push or a pull technique?
The technique choice may come down to operator preference in most cases, but there are some best practices. For example, when welding aluminum, a push angle is generally better because it helps the cleaning action of the oxidation layer on aluminum, similarly uphill position, a push angle is good for visibility and penetration. While if you use Flux Cored wire to weld carbon steel then a pull angle is going to work better in this case to give enough time to the slag not to be entrapped in the weld metal.
Q: What is the proper wire stick-out?
Maintaining a proper stick-out is important to achieving the best results in MIG welding, a too-long or a too-short stick-out will affect the weld quality and appearance. A 3/8-inch stick-out is a good starting point, but operators can deviate from that based on preference, wire diameter and accessibility to the weld.
Q: What amperage MIG welding gun is needed?
To choose the right MIG welding gun, consider the specifics of the application. The wire feed speed and wire diameter are two of the most important factors in determining proper gun amperage. Are you welding heavy wall materials, like heavy equipment or heavy steel structures? Those jobs will likely require a high deposition, hence a high-amperage welding gun — such as an Air-cooled 400-amp gun with at least a 60%-80% duty cycle or above, and in some cases a water-cooled gun. If you weld lighter walls and shorter beads, you may consider a 200 to 300-amp gun.
The most common amperage choice in the industry is a 300- to 400-amp, air-cooled MIG gun. This gun can address the majority of the MIG welding applications and can run the most common wire sizes such as 0.045” and 0.052”.
A good starting point would also be the welding procedure in place that specifies the amperage needed for the weld, which would help in choosing the gun’s amperage. Another easy way is to match the welding machine amperage output, a 400-amp welder would run well with a 400-amp gun in most cases, but this might not be the most effective way to select the right amperage gun when compared to the other methods mentioned above.
Q: How can an operation make consumables last longer?
Using the OEM consumables designed to be used with a specific MIG gun and welding system is important. Because these consumables are machined to very tight tolerances and go through high-quality measures which in turn is translated into higher quality welds and longer consumable life.
Be sure to choose a contact tip that is the appropriate size for the wire diameter — an oversized or undersized contact tip will wear faster and result in poor performance. In addition, follow the gun manufacturer’s recommendations for consumable installation and changeover, check connections regularly, install and trim to the right length, select the right nozzle material, size and recess/extension, and finally clean your consumables regularly and change them when needed.
Written by Mostafa Hanafy (mostafa.hanafy@tregaskiss.com) , Market Segment Manager, Tregaskiss and Bernard. Republished with permission from Fabricating and Metalworking (August 2023).
Employee Training: Best Practices for Preparing New Welders
Employee Training: Best Practices for Preparing New Welders
Estimated reading time: 4 minutes
Given the industry statistics regarding the number of experienced welders who are retiring from the field, many companies are likely training more new welders than ever before. By 2023, the nation’s workforce will need over 375,000 welders to satisfy the demands of several industries. [1]
Proper new welder training is essential to help companies meet quality and productivity goals. Consistent, thorough training also helps get welders onto the production floor as quickly as possible, allowing operations to meet throughput targets and customer timelines. Underscoring the importance of employee training, a study by the National Center on the Education Quality of the Workforce shows a 10% increase in workforce education can lead to an 8.6% increase in total productivity. [2]
There are various techniques and solutions for training new welders and resources available once training is complete.
3 primary learning styles
Welding is obviously a hands-on skill, but the best type of welder training for new employees may vary based on their learning style. Understanding the differences in learning styles can help companies tailor their training to best fit the way each individual learns. The three main learning styles are: [3]
Visual learning
People who have a visual learning style prefer to absorb new information by seeing the material being presented. They tend to remember things that are written down. Tips for reaching visual learners include turning notes into pictures, charts or maps; color coding parts of new concepts in any notes; focusing on learning the big picture first before drilling down to the details; and avoiding distractions.
Auditory learning
Learners who fall into this category prefer to learn through listening; they retain information best through hearing and speaking. Tips for reaching auditory learners include having them repeat the material out loud and in their own words; discussing the material in small groups; and having them read any new information or instructions out loud.
Kinesthetic learning
This type of learner prefers to learn by hands-on training. They would rather have a demonstration of how something works than a verbal explanation. Tips for this style of learner include taking frequent training breaks; have them learn new information while doing something active; and focus on hands-on demonstrations or lab work.
Covering the basics of welding training may differ for each type of learner. For example, a visual learner may want charts and graphics showing the different welding processes or parameters they will be using, while an auditory learner may want the trainer to explain those processes and parameters to them out loud. A kinesthetic learner may want to use a virtual reality or augmented reality welding training system to learn the skills in a hands-on manner.
Post-training tips
No matter what learning style is used in training, there are many solutions and welding technologies available that can help reinforce the information with welders once they are on the production floor.
Many of today’s welding power sources include technologies such as automatic presets and parameters windows that help ensure operators are using the best settings for the application. Weld data monitoring technology is another solution that can provide guidance to welders who have less experience. For example, some systems guide welders through the weld sequence in real time and will provide alerts if a weld is missed or outside of acceptable parameters.
Choosing welding equipment and consumables that are easy to install and use is another step companies can take to help welders of all experience levels produce high-quality welds. AccuLock™ welding consumables are designed to address common challenges in semi-automatic and robotic MIG welding applications. Simplified welding consumable replacement helps increase accuracy and reduce employee training requirements.
Resources for support
Many welding manufacturers also provide resources that companies can use to support welders after the training process. These resources include training manuals and welding guides found online, and how-to videos for welding equipment and consumables that are available on manufacturer websites or YouTube channels. QR codes on the welding equipment itself can be used to access how-to guides, training or machine updates.
These resources, coupled with the capabilities and ease-of-use engineered into today’s welding equipment and technologies, can help companies train new welders faster and support them once they are in production.
[1] American Welding Society: https://www.aws.org/foundation/page/workforce-development
[2] National Center on the Education Quality of the Workforce https://onlinemba.wsu.edu/blog/the-four-benefits-of-employee-training/
[3] Missouri State University: https://www.missouristate.edu/Assets/busadv/p-30.pdf
Making a MIG Gun Last in Harsh Manufacturing Environments
Making a MIG Gun Last in Harsh Manufacturing Environments
Whether it’s a high amperage application, high or low ambient temperatures, or humidity, harsh manufacturing environments can be tough on welding equipment — including MIG guns and consumables. Confined, cluttered or dirty weld cells can also negatively affect this equipment.
Cleaning and organizing the weld cell, plus areas upstream and downstream, can help prevent some issues — for example, damage to welding gun cables caused by forklifts running over them. However, operators can’t change factors such as heat or cold or the amperage required for the job. For that reason, it’s important to look for a durable MIG welding gun and consumables and know how to protect them. Not only does that help minimize costs for replacement, but it also supports productivity by reducing downtime for changeover.
What to look for
One of the best defenses against the elements in a harsh manufacturing environment is to choose a MIG gun with robust components and make certain it’s the best option for the job. Consider these factors.
Duty cycle
This is the most important factor in selecting a MIG gun for any operation, but especially in a harsh environment. Duty cycle is the amount of arc-on time within a 10-minute period that a gun is capable of being used. Manufacturers in the U.S. rate their MIG welding guns according to the National Electrical Manufacturers Association (NEMA), with the rating reflecting the temperatures at which the gun or cable becomes too warm for use. For example, a gun may be rated at 400 amps and 100% duty cycle, meaning it can weld the entire 10 minutes at 400 amps (or even longer at a lower amperage) without discomfort to the operator.
In areas of high heat and humidity, it is helpful to use a MIG gun offering 100% duty cycle and higher amperages than needed for the application. If a welding shop is experiencing 80% humidity and it is 100 degrees F outside, that ambient temperature will reduce the duty cycle — a 400-amp gun may drop from 100% duty cycle to a 60% duty cycle range.
Handles
MIG gun handles should be manufactured with materials designed to withstand heat. Those with added glass in the plastic mold material are particularly adept at resisting wear in harsh environments. Tubular handles are also an option, as they tend to be a bit larger, and they have a slight air gap between the handle and the power cable that adds to its durability and heat tolerance. However, each handle material and design can have its own pros and cons. High glass content will create a more brittle handle, while more malleable materials may withstand less heat but not break as easily if abused.
Trigger
Trigger designs vary by manufacturer. The best option to protect against harsh elements is a micro-switch trigger, which is sealed. MIG guns with straight handles typically have a trigger that is enclosed to protect against dirt and debris. Avoid contact triggers, as these feature a spring and two contacts that touch each other when the operator presses down on it. Dirt can get inside of these triggers and break the contacts, preventing good electrical connections.
Neck
A MIG welding gun neck with aluminum armor on the outside is a durable choice. This type of neck is also lightweight, so it is more comfortable for the operator. MIG gun neck grips can also increase comfort, as well as control.
Power cable
Look for a power cable with a thick rubber outer jacket. While this type of cable may add some to its stiffness and weight, it will last longer. It can better take the abuse of being dragged on the floor, run over edges and exposed to hot materials. There are also power cable jackets that further protect power cables in harsh environments. A good jacket option is one with a tubular design versus one with Velcro or buttons. A power cable with higher-quality grades and higher amounts of copper adds to its durability and performance, as well.
Consumables
Welding contact tips, nozzles and gas diffusers made from quality copper or chrome zirconium are reliable complements to a sturdy MIG gun. Typically, higher-quality welding consumables cost more upfront; however, they last longer. Having fewer changeovers during shifts can save money for labor and replacement consumables in the long run. Contact tips, like those in AccuLock™ S consumable systems, have 60% of the tip buried within the gas diffuser. This keeps heat from the weld away from the tip, so it lasts longer. Shielding gas also cools the contact tip tail to protect it.
Maintain and protect
Preventive maintenance is critical in any welding operation, but especially in harsh manufacturing environments. Purchasing a gun that is repairable and can be maintained versus thrown away is a smart investment. In the long term, operators and maintenance personnel can gain more life from the gun even when exposed to heat, humidity and other elements.
Periodically, remove the welding gun liner and blow out any dust or debris that accumulated with compressed air. Take care not to drag the liner on the ground, where it can pick up more dirt or inadvertently become damaged.
At the start of every shift, especially when operators share MIG guns, check all connections. Tighten connections along the length of the gun — between the welding contact tip, gas diffuser, neck, power cable and power pin. Also check that the screws on the handle are tight and the trigger is functioning. When using a MIG welding gun with a rotatable neck, be certain to tighten it to avoid wire feeding problems.
Being mindful
The best defense to protect a MIG gun used in a harsh manufacturing environment is to make sure to select a durable one in the first place. Look for quality components and take care to schedule preventive maintenance. Treat the MIG welding gun just like any other piece of equipment in the welding operation, caring for it with regular inspections. Doing so can increase its lifespan and help prevent downtime and the cost for replacement.
Using Root Cause Analysis to Address Welding Consumable Issues
Using Root Cause Analysis to Address Welding Consumable Issues
Estimated reading time: 4 minutes
Troubleshooting problems with welding consumables can be time-consuming and expensive. From the associated downtime to the cost of replacing contact tips, diffusers, nozzles and liners, companies stand to lose productivity and potentially miss production goals.
Applying root cause tools can help expedite the process. These are structured methods to narrow down the true cause of a problem and determine an exact solution.
At a high level, root cause analysis follows several key steps:
- Defining the problem
- Collecting information
- Identifying issues that are contributing to the problem
- Determining the root cause
- Recommending and implementing the solution
To successfully implement root cause tools, it’s important to keep an open mind about possible causes that are contributing to welding consumable problems and to be patient, as it may take time to determine a cause and solution. Analytical thinking, along with being thorough and unbiased in the assessment, is a must.
The 5 Whys
The 5 Whys is a common and simple root cause tool to apply to welding consumable issues. It involves asking “Why?” five times, and providing answers, to drill down to the root cause. In some instances, the solution may become apparent after fewer than five questions. Other times, it may take more. It is also possible that the questioning may become circular and require branching off into another line of questions. Once the root cause is identified, companies can home in on the right solution and determine ways to prevent further problems.
For example, companies may ask the following if there are issues in a semi-automatic welding operation:
- Why do we have an erratic arc? Because the welding wire is feeding poorly.
- Why is the welding wire feeding poorly? Because the wire feeding path is blocked.
- Why is the wire feeding path blocked? Because the liner is kinked up.
- Why is the liner kinked up? Because it was trimmed incorrectly.
- Why was the liner trimmed incorrectly? Because welding operators didn’t measure it properly
Knowing this information, companies may determine they need to train welders to use a liner gauge during trimming and installation. AccuLock™ S consumables are another option, as these have a liner that eliminates liner trim length errors without the need to measure. The liner locks and aligns at the front and back of the gun to provide a flawless wire feed path.
To gain the best results from The 5 Whys, engage employees who have hands-on experience with the welding process. Quality engineers are also great resources to include.
Failure Modes & Effects Analysis (FMEA)
FMEA assesses how a failure could occur, its causes and what the potential consequences of a failure would be. FMEA follows the same logic as The 5 Whys to drill down to a root cause. Engineers use this tool proactively during the design of components like welding consumables. Companies can also use FMEA over the course of using these products as a troubleshooting method.
Keeping with the example of welding consumables, a FMEA for troubleshooting may look like this in a robotic welding operation:
- Failure mode: Off-location welds.
- Potential consequence: Non-conforming parts.
- Potential cause: Cross-threaded contact tip.
- Current process controls: Train employees to install contact tips correctly.
Potential solution: Use a contact tip that can’t be cross-threaded. These can be found in the AccuLock R consumables system.
When using FMEA or The 5 Whys to troubleshoot welding consumables issues, it’s important to look at all aspects of the situation to accurately determine the root cause. While it may seem time-consuming, investing in the use of these methods can actually save time in the long term — not to mention frustration and costs.
Welder Training Tips to Help Improve Productivity
Welder Training Tips To Help Improve Productivity
Estimated reading time: 6 minutes
Improving productivity in semi-automatic operations isn’t simply about welding faster and working harder. Instead, there are ways to create consistency in the process and support quality so that companies can avoid downtime that adversely affects throughput.
When training new welders, it’s important to provide a solid foundation of knowledge to achieve the best results. Taking the time to establish and expand welders’ skill sets shows welders companies are invested in them, and as welders gain more experience, they become more confident. The aim is to empower them and provide all the information necessary to be productive.
To instill good habits from the start, consider some key training tips.
Put safety first
A safe welder is a productive welder. By training new welders to follow welding safety protocols, there is less risk of lost productivity due to injury. Wearing the appropriate personal protective equipment (PPE) is important. This includes a properly fitted helmet, safety glasses, flame-resistant jacket or sleeves, welding gloves and steel-toed, rubber-soled boots. If the process is prone to higher levels of fume generation, correct use of a respirator is necessary. Train welders to read and follow all equipment labels and their owner’s manual carefully before operating welding equipment. Training also includes checking the power source ground, securing workpieces in the best possible manner and keeping their heads out of the weld plume when welding.
Establish consistent weld prep
Following best practices for weld prep supports high weld quality, reduces rework and scrap, and improves productivity. As part of new welder training, welders should understand their power source settings, type and levels of the shielding gas being used, and how to clean the base material. Checking that all welding consumable connections are tight can minimize electrical resistance that could lead to burnbacks (the formation of a weld in the contact tip) and downtime for tip changeover.
Install welding consumables correctly
Downtime to address liner issues is common in semi-automatic welding operations and is typically caused by incorrect installation. This can lead to bird-nesting (a tangle of wire in the drive rolls), poor wire feeding, an erratic arc, wire chatter, burnbacks and more. Always use a liner gauge when trimming a liner; or consider a consumable system like AccuLock™ S, which provides error-proof liner installation without measuring. The liner locks and is aligned to the power pin and the contact tip to ensure proper wire feeding. New welders should also learn to install and tighten contact tips according to the consumable manufacturer’s recommendation.
Focus on comfort
Training welders to pay attention to their posture and the angle they hold their MIG welding gun can help reduce fatigue and the risk of welding-related musculoskeletal disorders that lead to lost productivity. Whenever possible, welders should position themselves so they are welding the workpiece in the range between their waist and shoulders. This may require a work stool or adjustable chair. Welders should also keep their hands and welding gun at or slightly below elbow height. Gaining good visibility to the weld joint can encourage proper posture.
Follow welding procedures
Welding procedure specifications (WPS) are a means to create consistency in the welding operation by taking the guesswork out of the process. This document outlines welding parameters, filler metal type and diameter, wire feed speed (WFS), weld pass sequence and more. Training new welders to follow the details in a WPS can help ensure that they produce quality welds and remain productive.
Use the right equipment
New welders should be trained to use the best equipment and tools for the job — and ones that best suit them. A MIG welding gun that fits the welder’s hand comfortably will help maximize their time when welding. Using a hammer for repositioning a part, as opposed to the MIG gun itself, can prevent damage to the gun that leads to downtime for repairs or replacement.
Likewise, having the correct wrench for installing gas diffusers or welpers for tightening contact tips helps ensure snug connections and lessens the opportunity for issues. Using the wrong tools or not tightening parts properly leads to loose connections that cause electrical resistance. This, in turn, increases heat and wears out the equipment prematurely.
Employ proper techniques
Welding techniques vary according to the process, the welding position and the thickness of the base material. For example, when MIG welding with solid or metal-cored wire, welders need to learn to use a push technique, while a flux-cored process requires a drag technique. Train welders on the proper gun angles for flat, horizontal and out-of-position welding applications so they are able to fill the joint with the appropriate amount of weld metal and avoid issues like lack of fusion.
Recognize signs of trouble
Training new welders to quickly identify issues in the welding process can minimize downtime for troubleshooting. They should be given the guidance to identify the causes of common problems like porosity, burnbacks, poor deposition and more, along with their solutions. Welders should also be able to recognize signs that equipment needs to be repaired or replaced — for example, a welding contact tip that is keyholing (wearing at the bore unevenly) or a gun that has nicks in the power cable. Companies can provide troubleshooting cards with quick checklists to keep in the weld cell as reminders.
Keep communication open
Clearly communicating expectations to new welders and having supervisors who are responsive to questions are vital parts of training. It is about both learning and listening. As training continues and welders grow their skill sets, it’s important to establish two-way feedback. This way everyone can find common ground on what best practices could be. In some cases, new welders may identify a way to improve the operation based on experience they have from another job.
Successful new welder training
When companies commit to providing thorough new welder training, the aim is to establish skills that lead to consistency in quality and reduce downtime. The more they can avoid secondary work or additional processes, the better productivity will be. Plus, supporting the comfort and safety of welders can help make sure they perform their best every day, build confidence and help retain them as employees.
5 Tips for Improving Weld Quality
5 Tips for Improving Weld Quality
Estimated reading time: 7 minutes
Establishing consistent levels of weld quality is important for attaining production goals and a better bottom line in semi-automatic welding operations. However, there are many factors that can negatively impact those efforts, including a lack of skilled labor, inadequate or aging equipment or using the wrong welding consumables.
To avoid costly rework associated with poor weld quality, it’s critical to implement proper welder training. Evaluating the welding operation on a regular basis for issues can also help, along with following these key tips.
No. 1: Size contact tips correctly
Welding contact tips are available in a range of diameters — typically 0.023 to 1/8 inches — to accommodate different welding wire sizes. The wire packaging, in part, determines what size contact tip is appropriate to support good weld quality.
Welding wires in larger drums — 500 pounds or more — have a larger cast and are flatter so there is less degree of arc. This means there is less opportunity for the wire to make consistent contact when feeding down the bore of the contact tip, resulting in an erratic arc and weld quality issues. To avoid problems when using copper and chrome zirconium welding contact tips (with Bernard and Tregaskiss consumables), undersize them for the diameter of wire. For example, match an 0.045-inch wire to a 0.039-inch contact tip. For other manufacturers’ contact tips, request recommendations.
Copper and chrome zirconium contact tips can be matched size for size with wire on spools or in drums less than 500 pounds since the wire has a tighter cast.
For AccuLock™ HDP contact tips, the wire and tip size can be matched regardless of the welding wire drum or spool size.
No. 2: Size and change over liners properly
As with contact tips, welding liners are available in various diameters and ranges, from 0.035 to 0.045 inch or from 0.045 to 1/16 inch. To avoid issues like burnback (the fusing of a weld in a contact tip), poor wire feeding and an erratic arc that can be detrimental to weld quality, match the diameter of welding wire to that of the liner. This supports the wire as it feeds through the liner.
It’s equally important to trim the liner properly. A liner that is too short can create wire chatter, an erratic arc and bird-nesting (a tangle of wire in the drive rolls). If the liner is too long, it can cause the wire to weave. Both situations can cause poor welds and, potentially, rework.
Always use the gauge provided by the manufacturer to ensure that the liner is trimmed correctly. The AccuLock S consumable system is also a good option, as it provides error-proof liner replacement. The liner loads through the neck at the front of the gun and is locked and trimmed flush with the power pin at the back of the gun, which eliminates the need to measure.
No. 3: Keep electrical resistance low
Electrical resistance — or interference with the flow of electricity in a semi-automatic MIG gun’s circuit — generates heat and can impede weld quality by negatively impacting the gun’s components. There are several causes that can be rectified to prevent issues such as inconsistent weld appearance or an erratic arc.
Through ongoing use, connections begin to wear and loosen, leading to electrical resistance. Address this problem by tightening connections between the gas diffuser, gun neck and handle, as well as the connections from the power cable to the power pin and wire feeder.
Power cable wear that results in hotspots can also lead to electrical resistance. This wear may not always be visible, so as a course of troubleshooting, operators should consider this problem as a cause of poor weld quality. Replace the cable as necessary to prevent issues. Likewise, increased electrical resistance can occur in the gun handle, since it is an area of high use and bending. Look for signs of wear and replace as needed.
No. 4: Be mindful of cleanliness
There are various aspects of cleaning and weld prep that can help support good weld quality. Always follow proper procedures for cleaning the base material to prevent defects like porosity that can be caused by welding through dirt, oil and debris.
It’s also important to be proactive about cleaning consumables. For example, weld spatter buildup in the nozzle or in the ports in the gas diffuser can hinder shielding gas coverage, which also leads to porosity. Clean or replace these consumables when excessive spatter is evident. Operators can also apply anti-spatter compound to the consumables by dipping the front inch and a half of the nozzle into the liquid. Use the anti-spatter compound sparingly to avoid damaging the nozzle insulator.
Storing consumables in a clean area minimizes the opportunity for dust, oil or other contaminants to adhere to the surface of the welding contact tip, nozzle and diffuser and adversely affect weld quality. A covered container with compartments for each welding consumable is a good option to protect them.
Also consider how to handle the welding liner during changeover. Be careful not to drag the liner on the floor while feeding it into the gun, since doing so can cause debris to collect on it and be pulled into the gun.
No. 5: Plan for inspection and maintenance
Preventative maintenance and ongoing care of the MIG gun and consumables can go far in supporting high weld quality. Set a schedule to inspect, maintain and repair the components.
Although often overlooked during regular inspections, the O-rings found throughout the gun are important to assess. If they start to degrade or break, they can cause shielding gas leaks that lead to porosity and potentially extra costs for shielding gas if the operator increases gas flow to compensate for the leak. Check O-rings on the power pin, gas diffuser and liner during routine preventive maintenance and replace these components as needed.
Look for damage to the power cable, such as nicks or tears that can impede gas flow. Visually inspect the gun handle for cracks or missing screws and the trigger for sticking or malfunction. Repair or replace as necessary.
Last, inspect the welding contact tip for keyholing (an oblong wear of the bore); this can cause drifting wire and arc start failures that affect weld quality.
Long-term results
Improving weld quality is a matter of ongoing evaluation. Supervisors and managers overseeing semi-automatic welding operations should regularly consult with welding operators to make sure they are following best practices. Ongoing training and quickly troubleshooting issues can also support good weld quality and prevent costly downtime and rework.
From Consumables to Communication: Reducing Human Error in Welding
From Consumables to Communication: Reducing Human Error in Welding
Estimated reading time: 4 minutes
Human error can take its toll on welding operations, leading to downtime and lost productivity, poor quality and increased costs. It can result from a variety of factors. An operator may know how to manage a process, but periodically misses a step or forgets to complete a task. Or an operator may believe he is conducting a task in the correct manner, but it is wrong.
To reduce problems, it’s important to provide proper training to semi-automatic and robotic welding operators. This includes not only training on the welding process, but also on how to spot errors when they occur.
Companies may want to rely on principles of poka-yoke to help. These principles could be applied in several ways in a welding operation.
- Elimination: Remove or change parts of the welding process that cause problems
- Prevention: Investing in equipment or processes that prevent errors
- Replacement: Substitute consumables with ones that are more consistent
- Facilitation: Streamline operations to reduce the risk of a welding operator causing an error
- Detection: Identify errors early and correct them before they lead to costly rework
- Mitigation: Find ways to reduce the impact of errors on the welding operation
With these high-level, error-proofing ideas in mind, it’s possible to put them into action in several specific ways.
Color-coded parts
Investing in welding consumables with color-coded parts can help eliminate confusion during installation. AccuLock™ S liners and power pin caps are color coded to make it easy to identify which power pin cap is compatible with which liner. For example, power pin caps with red washers are compatible with liners that have red shrink tube and so on.
Welding procedures
Implementing a welding procedure specification (WPS), and training operators to follow it, can help ensure consistent, high-quality welds. A WPS outlines details on the welding process and parameters, weld pass sequences, filler metal type and size, and more.
Error-proof consumables design
For operations with a mix of welding arcs or for all automated welding operations, AccuLock R consumables are designed to prevent errors associated with cross threading during installation. They feature a long contact tip tail that aligns in the diffuser prior to the thread engaging. This allows operators to install the tip easily and accurately. The AccuLock S welding gun liner also offers error-proof liner trimming with no measuring required for semi-automatic welding operations.
Long-lasting consumables
Consumables that last longer require less changeover, which means less interaction by the welding operator in the welding cell and less potential for errors. AccuLock contact tips offer a longer lifespan, particularly the AccuLock HDP tips. These last up to ten times longer than standard contact tips and are designed for use in pulsed MIG welding applications, where waveforms tend to be harsher on tips.
Inventory reduction
Taking steps to simplify inventory by having a lower variety of consumables can help prevent errors during changeover. The AccuLock S and AccuLock R consumable systems share a common contact tip, so the tip can be used in Bernard semi-automatic MIG guns and Tregaskiss robotic and fixed automatic guns.
Communication and reporting
Keeping open lines of communication among welding operators and with management is an important way to minimize and rectify errors. Knowing what is expected in the welding process is a good start, as is reporting errors when they occur so that they can be fixed and don’t lead to further complications.
Preventing errors in a welding operation requires attention to detail, a commitment to making improvements, and collaboration among welding operators and management. Everyone needs to take a vested interest in the process, knowing that it will help improve quality and productivity — and ultimately make everyone’s job easier.
MIG Welding Basics
MIG Welding Basics
Estimated reading time: 3 minutes
When it comes to MIG welding, it’s important for new welders to start with the basics to set a solid foundation for success. The process is generally forgiving, making it simpler to learn than TIG welding, for example. It can weld most metals and, as a continuously fed process, offers greater speed and efficiency than stick welding.
Welding safety
The very first consideration for new welders is welding safety. It is imperative to read and follow all labels and the equipment Owner’s Manuals carefully before installing, operating, or servicing welding equipment. Welders must wear proper eye protection to avoid arc flash burns and sparks. Always wear safety glasses and a welding helmet set to the appropriate shade level. Proper personal protective equipment attire is also critical to protect the skin from electric shock and burns. This includes:
- Leather shoes or boots.
- Leather or flame-resistant welding gloves
- Flame-resistant welding jacket or welding sleeves
Adequate ventilation is also an important safety factor. Welders should always keep their head out of the weld plume and be sure that the area in which they are welding has adequate ventilation. Some type of fume extraction may be needed. Fume extraction guns that remove the exhaust at the arc are also helpful, and are very efficient compared to floor or ceiling capture.
Welding transfer modes
Depending on base material and shielding gas, welders can weld in various welding transfer modes.
Short circuit is common for thinner materials and operates at lower welding voltage and wire feed speed, so it is slower than other processes. It also tends to produce spatter that requires post-weld cleaning, but overall, it is an easy process to use.
Globular transfer operates at higher wire feed speeds and welding voltages than short circuit and works for welding with flux-cored wire with 100% carbon dioxide (CO2) (see details on CO2 in next section). It can be used on 1/8-inch and thicker base materials. Like short-circuit MIG welding, this mode produces spatter, but it is a fairly fast process.
Spray transfer offers a smooth, stable arc, making it appealing to many new welders. It operates at high welding amperages and voltage, so it is fast and productive. It works well on base materials that are 1/8 inch or more.
Welding shielding gas
In addition to protecting the weld pool from the atmosphere, the type of shielding gas used for MIG welding impacts performance. Weld penetration, arc stability and mechanical properties depend on shielding gas.
Straight carbon dioxide (CO2) offers deep weld penetration but has a less stable arc and more spatter. It is used for short circuit MIG welding. Adding argon to a CO2 mixture allows for use of spray transfer for higher productivity. A balance of 75% argon and 25% is common.
Beyond the basics
Along with practice, knowing some key information can help new welders better understand the MIG welding process. It’s also important to be familiar with the equipment, including MIG welding guns and welding liners. Understanding how to select and maintain this equipment can go far toward establishing good welding performance, quality and productivity.
This is the first article in a three-part series on welding basics. Read article two, MIG Welding Glossary: Terms to Know and article three, MIG Welding Techniques: What to Know.
MIG Welding Glossary: Terms To Know
MIG Welding Glossary: Terms To Know
Estimated reading time: 3 minutes
Welders use MIG welding in many industries — fabrication, manufacturing, shipbuilding and rail to name a few. While it is a common process, it requires attention to detail, and it is helpful to know some key terms associated with it. As with any process, the better the understanding, the better the results.
Bird-nesting
The tangling of welding wire in the drive rolls of the wire feeder. This typically happens when the wire doesn’t have a smooth feeding path due to a liner being cut too short, the wrong size liner or tip being used, or incorrect drive roll settings. Resolve this issue by trimming the liner properly and ensuring that the feed path of the wire is as smooth and straight as possible.
Burnback
Occurs when the wire melts inside the contact tip before reaching the workpiece. It results from incorrect contact-tip-to-work distance (CTWD) — the distance between the end of the tip and the base metal — or a too-slow wire feed speed (WFS). It can also be caused by incorrectly trimmed liner and incorrect parameters. Remedy the problem by increasing WFS, adjusting CTWD, trimming the liner according to the manufacturer’s recommendation and modifying weld parameters.
Deposition rate
Refers to how much filler metal is deposited into a weld joint over a specified period of time, measured in pounds or kilograms per hour (lbs/hr or kg/hr).
Discontinuity
A flaw in the structure of a weld that does not pose a risk of failure. It differs from a weld defect that can affect the integrity of a weld once in service.
Duty cycle
Refers to the percentage of time in a 10-minute period a gun can be used at a specific amperage (arc-on time) without becoming too hot to handle or overheating. A gun’s duty cycle is affected by the type of shielding gas being used for welding. For example, a MIG gun may be rated at 100% duty cycle with 100% CO2 shielding gas, meaning it can weld the entire 10 minutes without issues; or it could have a gun rating of 60% duty cycle with mixed gases.
Electrode extension
The distance the welding wire extends from the end of the contact tip to where the wire melts. As electrode extension increases, amperage decreases, which reduces joint penetration. Also commonly referred to as tip-to-workpiece distance.
Heat-affected zone
Often referred to as HAZ, it is the portion of the base material surrounding the weld that hasn’t melted but has had its properties changed at a microstructure level due to the heat input. Cracking can occur here.
Incomplete fusion
Also called lack of fusion, it occurs when the weld fails to fuse completely with the base material or a previous weld pass in multi-pass welding. Typically, it is the result of an incorrect MIG gun angle.
Porosity
A cavity-like discontinuity that occurs when gas becomes trapped in the weld upon solidification of the molten weld pool. It is most often caused by poor shielding gas coverage or base material contamination.
Weld penetration
Refers to the distance the weld fuses below the surface of the base material. Incomplete weld penetration occurs when the weld doesn’t completely fill the root of the joint.
This is the second article in a three-part series on welding basics. Read article one, MIG Welding Basics and article three, MIG Welding Techniques: What to Know.
MIG Welding Techniques: What To Know
MIG Welding Techniques: What To Know
Estimated reading time: 2 minutes
Understanding some proper techniques for MIG welding can help welders gain good weld quality and avoid the frustration and cost of rework. Everything from proper positioning of the MIG welding gun to travel angle and travel speed can make an impact.
Consider these four recommended techniques:
- While welding, hold the MIG welding gun straight, using both hands to steady it and keeping them at or just below elbow height. This approach not only makes it easier to make a quality weld, but it also helps improve ergonomics. That is particularly important for welders welding for a long period of time, so they can avoid injury.
- Welders should keep a contact-tip-to-work distance (CTWD) of approximately 3/8 to 1/2 inch for short-circuit welding and around 3/4 inch for spray transfer MIG welding.
- Use the proper travel angle. When push welding, welders should hold the gun at a 10-degree angle. This technique creates a wide bead with less joint penetration. For a pull technique, welders use the same angle, pulling the gun toward their body. This results in more penetration and a narrow weld bead.
- Maintain a consistent travel speed with the wire at the leading edge of the weld pool. Too fast of a travel speed creates a narrow bead that may not fully tie in at the weld toes and may lack proper penetration. Traveling too slow creates a wide weld, also with inadequate penetration. Both too slow and too fast travel speeds can cause burn-through on thin base metals.
As with any welding process, practice is a large part of MIG welding success. Along with good techniques, it’s also important to properly prepare and clean the base material before welding and to maintain the MIG welding gun and consumables properly. This can reduce downtime for addressing equipment issues or troubleshooting weld defects and problems such as poor wire feeding.
This is the third article in a three-part series on welding basics. Read article one, MIG Welding Basics and article two, MIG Welding Glossary: Terms to Know.
Solving Common Causes of Welding Porosity
Solving Common Causes of Welding Porosity
Estimated reading time: 7 minutes
Porosity, cavity-type discontinuities formed by gas entrapment during solidification, is a common but cumbersome defect in MIG welding and one with several causes. It can appear in semi-automatic or robotic applications and requires removal and rework in both cases — leading to downtime and increased costs.
The major cause of porosity in steel welding is nitrogen (N2), which gets involved in the welding pool. When the liquid pool cools down, the solubility of N2 is significantly reduced and N2 comes out of the molten steel, forming bubbles (pores). In galvanized/galvanneal welding, evaporated zinc can be stirred into the welding pool, and if there is not enough time to escape before the pool solidifies, it forms porosity. For aluminum welding, all porosity is caused by hydrogen (H2), by the same way as N2 works in steel.
Welding porosity can appear externally or internally (often called sub-surface porosity). It can also develop at a single point on the weld or along the entire length, resulting in weak welds.
Knowing how to identify some key causes of porosity and how to quickly solve them can help improve quality, productivity and the bottom line.
Poor Shielding Gas Coverage
Poor shielding gas coverage is the most common cause of welding porosity, as it allows atmospheric gases (N2 and H2) to contaminate the weld pool. Lack of proper coverage can occur for several reasons, including but not limited to poor shielding gas flow rate, leaks in the gas channel, or too much air flow in the weld cell. Travel speeds that are too fast can also be a culprit.
If an operator suspects poor flow is causing the problem, try adjusting the gas flow meter to ensure the rate is adequate. When using a spray transfer mode, for example, a 35 to 50 cubic feet per hour (cfh) flow should suffice. Welding at higher amperages requires an increase in flow rate, but it’s important not to set the rate too high. This can result in turbulence in some gun designs that disrupts shielding gas coverage.
It’s important to note that differently designed guns have different gas flow characteristics (see two examples below). The “sweet spot” of the gas flow rate for the top design is a lot larger than that of the bottom design. This is something a welding engineer needs to consider when setting up the weld cell.
Also check for damage to the gas hose, fittings and connectors, as well as O-rings on the power pin of the MIG welding gun. Replace as necessary.
When using fans to cool operators or parts in a weld cell, take care that they are not pointed directly at the welding area where they could disrupt gas coverage. Place a screen in the weld cell to protect from external air flow.
Re-touch the program in robotic applications to make sure there is a proper tip-to-work distance, which is typically ½ to 3/4 inch, depending on the desired length of the arc.
Lastly, slow travel speeds if the porosity persists or consult a MIG gun supplier for different front-end components with better gas coverag
Base Metal Contamination
Base metal contamination is another reason porosity occurs — from oil and grease to mill scale and rust. Moisture can also encourage this discontinuity, especially in aluminum welding. These types of contaminants typically lead to external porosity that is visible to the operator. Galvanized steel is more prone to subsurface porosity.
To combat external porosity, be certain to thoroughly clean the base material prior to welding and consider using a metal-cored welding wire. This type of wire has higher levels of deoxidizers than solid wire, so it is more tolerant of any remaining contaminants on the base material. Always store these and any other wires in a dry, clean area of similar or slightly higher temperature than the plant. Doing this will help minimize condensation that could introduce moisture into the weld pool and cause porosity. Do not store wires in a cold warehouse or outdoors.
When welding galvanized steel, the zinc vaporizes at a lower temperature than the steel melts, and fast travel speeds tend to make the weld pool freeze quickly. This can trap zinc vapor in the steel, resulting in porosity. Combat this situation by monitoring travel speeds. Again, consider specially designed (flux formula) metal-cored wire that promotes zinc vapor escape from the welding pool.
Clogged and/or Undersized Nozzles
Clogged and/or undersized nozzles can also cause porosity. Welding spatter can build up in the nozzle and on the surface of the contact tip and diffuser leading to restricted shielding gas flow or causing it to become turbulent. Both situations leave the weld pool with inadequate protection.
Compounding this situation is a nozzle that is too small for the application and more prone to greater and faster spatter buildup. Smaller nozzles can provide better joint access, but also obstruct gas flow due to the smaller cross-sectional area allowed for gas flow. Always keep in mind the variable of the contact tip to nozzle stickout (or recess), as this can be another factor that affects shielding gas flow and porosity with your nozzle selection.
With that in mind, make sure the nozzle is large enough for the application. Typically, applications with high welding current using larger wire sizes require a nozzle with larger bore sizes.
In semi-automatic welding applications, periodically check for welding spatter in the nozzle and remove using welder’s pliers (welpers) or replace the nozzle if necessary. During this inspection, confirm that the contact tip is in good shape and that the gas diffuser has clear gas ports. Operators can also use anti-spatter compound, but they must take care not to dip the nozzle into the compound too far or for too long, since excessive amounts of the compound can contaminate the shielding gas and damage the nozzle insulation.
In a robotic welding operation, invest in a nozzle cleaning station or reamer to combat spatter buildup. This peripheral cleans the nozzle and diffuser during routine pauses in production so that it does not affect cycle time. Nozzle cleaning stations are intended to work in conjunction with an anti-spatter sprayer, which applies a thin coat of the compound to the front components. Too much or too little anti-spatter fluid can result in additional porosity. Adding in air blast to a nozzle cleaning process can also aid in clearing loose spatter from the consumables.
Maintaining quality and productivity
By taking care to monitor the welding process and knowing the causes of porosity, it’s relatively simple to implement solutions. Doing so can help ensure greater arc-on time, quality results and more good parts moving through production.
Employee Retention: Best Practices for Keeping Welders Engaged
Employee Retention: Best Practices for Keeping Welders Engaged
Estimated reading time: 4 minutes
The welding industry, like many others, is challenged by a labor shortage — and one that is growing. By 2023, the American Welding Society (AWS) anticipates the welder shortage to reach approximately 375,000, as an increasing number of experienced welders reach retirement age and leave the field.[1] With those statistics in mind, it’s more important than ever for companies to take steps to retain the welders they have.
Employee retention is critical for several reasons. It helps support quality and productivity initiatives, which in turn makes it easier to meet customer demands. It also prevents overworking welders — an issue that can lead to low morale and a poor company culture. In addition, retaining welders helps maintain the bottom line. Turnover can cost companies significantly in terms of recruiting and retraining new welders, as well as for downtime in production due to lack of a full workforce. [2]
Fortunately, there are some best practices that can help companies create a positive environment and keep welders interested in the job.
Provide proper welder training
Empowering welders is important to instill a sense of interest and pride in the job —and that process should start from the very beginning. It’s reported that strong onboarding and training can help companies retain 82% of new hires. [3]
With proper training, welders can feel confident in their ability to do the job and help train new welders. Start with establishing good welding habits and creating a familiarity with the welding process. This includes training new welders on how to set up their power source accurately and safely and on what welding parameters to use. Equally important is providing guidance on the best technique for the process and application to minimize weld defects. Establishing a comfort level with following welding procedures is also a valuable part of welder training. [4]
For more experienced welders, offering more advanced training opportunities can help keep them engaged. This could include training to weld on more complicated applications or complex parts, robotic welding programming and more.
Create a clean, safe environment
Along with providing appropriate personal protective equipment (PPE), such as helmets, gloves, safety glasses and jackets, it is also important that the environment is safe. That means ensuring the welding cell and surrounding areas are free of clutter and any tripping hazards. It also entails proper ventilation. Companies can achieve that by removing weld fume at the source with a fume extraction gun, or with a mobile, wall-mounted system or a centralized fume extraction system. A clean, safe welding environment is more appealing for welders to work in — and it can provide an edge over competitive companies when it comes to employee retention. Additionally, be certain to train employees on all company safety protocols and welding equipment manufacturer’s safety precautions. Doing so can help create a culture of safety in which everyone is contributing. [5]
Offer easy-to-use welding equipment
Complicated equipment can be difficult to use, especially for inexperienced welders, leading to frustration about errors and downtime. This holds true not only for power sources, but also MIG guns and consumables: contact tips, nozzles, gas diffusers and liners. Liners, in particular, can be troublesome to install since it’s easy to trim them too long or too short, the latter of which happens more often. When the liner is too short, it can cause burnbacks, an erratic arc and poor wire feeding. Look for a consumable system that offers error-proof liner replacement for easier installation. This leaves welders more time to hone their welding skills while spending less time on troubleshooting. In automated welding operations, it is important to have equipment that is easy and intuitive to maintain and program after the proper training. This includes teach pendants with easy-to-use controls for inputting new parameters and requirements for the application.
Provide growth and advancement opportunities
Offering welders a chance to advance and learn new skills can be a good way to retain those who are interested in those opportunities. Growth can take many forms, whether it’s stepping into a new role or shouldering additional responsibilities within a current position. Certifications are another avenue for growth. The American Welding Society (AWS) offers its AWS Certified Welder performance-based program so welders can expand their knowledge and technique — from plate to pipe welding with a variety of processes. There are additional programs that support advancement, including one for a certified welding supervisor. [6]
Along with these best practices, keeping open lines of communication with welders is key — as it is in any work environment. Staying involved and creating a sense of community in which everyone is contributing to the well-being of the company can go a long way in keeping welders interested and engaged.
8 Manufacturing Cost-Reduction Strategies for Welding Operations
8 Manufacturing Cost Reduction Strategies for Welding Operations
Cost overruns in a manufacturing welding operation can come from many places. Whether it’s a semi-automatic or robotic weld cell, some common culprits of unnecessary costs are unplanned downtime and lost labor, consumable waste, repairs and rework, and lack of operator training.
Many of these factors are tied together and influence each other. A lack of operator training, for example, can result in more weld defects that require rework and repair. Not only do repairs cost money in additional materials and consumables used, but they also require more labor to do the work and any additional weld testing.
Repairs can be especially costly in an automated welding environment, where constant progression of the part is crucial to overall throughput. If a part isn’t welded correctly, it may still continue through all steps of the process. If the defect isn’t caught until the end of the process, all the work must be redone.
Companies can use these eight tips to help optimize consumable, gun and equipment performance — and reduce costs in both semi-automatic and robotic welding operations.
This article was published as an exclusive on thefabricator.com. Read the full article here.
Creating a Smooth Wire Feeding Path for MIG Welding
Creating a Smooth Wire Feeding Path for MIG Welding
In MIG welding applications, having a smooth wire feeding path is critical. The welding wire must be able to feed easily from the spool on the feeder through the power pin, liner and gun and up to the contact tip to establish the arc. This allows the welding operator to maintain consistent levels of productivity and achieve good weld quality, while also minimizing costly downtime for troubleshooting and potential rework.
However, there are several issues that can disrupt wire feeding. These can cause a host of problems, including an erratic arc, burnbacks (the formation of a weld in or on the contact tip) and birdnesting (a tangle of wire in the drive rolls). For new welding operators who may not be as familiar with the MIG welding process, these problems can be especially frustrating. Fortunately, there are steps to easily prevent problems and create a reliable wire feeding path.
Welding liner length has a big impact on how well the wire will feed through the entire path. Too long of a liner can result in kinking and poor wire feeding, whereas a liner that is too short won’t provide enough support to the wire as it passes through. This can ultimately lead to micro-arcing within the contact tip that causes burnbacks or premature consumable failure. It can also be the cause of an erratic arc and birdnesting.
Trim the liner correctly and use the right system
Unfortunately, welding liner trimming issues are common, particularly among less experienced welding operators. To take the guesswork out of trimming a welding gun liner correctly — and achieve a flawless wire-feeding path — consider a system that eliminates the need for measuring the liner for replacement. This system locks the liner in place at the back of the gun, allowing the welding operator to trim it flush with the power pin. The other end of the liner locks at the front of the gun at the contact tip; it is concentrically aligned between the two points, so the liner won’t extend or contract during routine movements.
When using a conventional liner, avoid twisting the gun when trimming the liner and use a liner trim gauge when provided. Liners with an interior profile that imparts less friction on the welding wire as it goes through the liner are a good choice for achieving efficient wire feeding. These have a special coating on them and are coiled out of a larger profile material, which makes the liner stronger and offers smooth feeding.
Use the right contact tip and install correctly
Matching the welding contact tip size to the diameter of wire is another way to maintain a clear wire feeding path. For example, an 0.035-inch wire should be matched to the same diameter contact tip. In some cases, it may be desirable to decrease the contact tip by one size to gain better wire feeding and arc control. Ask a trusted welding consumables manufacturer or welding distributor for recommendations.
Look for wear in the form of keyholing (when the contact tip bore becomes worn and oblong) since this can cause a burnback that prevents the wire from feeding.
Be sure to install the contact tip correctly, tightening it past finger tight to avoid tip overheating, which can hinder wire feeding. Consult the operations manual from the welding contact tip manufacturer for the recommended torque specification.
Choose the right drive rolls and set tension properly
Drive rolls play a significant role in ensuring a MIG welding gun has a smooth wire feeding path.
The size of the drive roll should match the size of the wire being used and the style depends on the wire type. When welding with solid wire, a V-groove drive roll supports good feeding. Flux-cored wires — both gas- and self-shielded — and metal-cored wires work well with V-knurled drive rolls. For aluminum welding, use U-groove drive rolls; aluminum wires are very soft, so this style won’t crush or mar them.
To set the drive roll tension, turn the wire feeder knob to one half turn past slippage. Pull the trigger on the MIG gun, feeding the wire into a gloved hand and slowly curling it. The wire should be able to feed without slipping.
Understand the impact of welding wire on feedability
The quality of welding wire and the type of packaging it is in both affect wire feeding. High-quality wire tends to have a more consistent diameter than low-quality ones, making it easier to feed through the entire system. It also has a consistent cast (the diameter when a length of wire is cut off the spool and placed on a flat surface) and helix (the distance the wire rises from the flat surface), which add to the wire’s feedability. While higher-quality wire may cost more upfront, it can help reduce long-term costs by minimizing the risk of feeding issues.
Wire from large drums typically have a large cast when dispensed from the packaging, so they tend to feed straighter than wires from a spool. If the welding operation’s volume can support a larger drum, this may be a consideration for both wire feeding purposes and for reducing downtime for changeover.
Making the investment
In addition to following best practices to establish a clear wire feeding path — and knowing how to quickly troubleshoot problems — having reliable equipment is important. The upfront investment for a high-quality wire feeder and durable welding consumables can pay off in the long term by reducing issues and the costs associated with wire feeding problems. Less downtime means more focus on producing parts and getting them out to customers.
Improve Productivity by Preventing 5 Common MIG Welding Problems
Improve Productivity by Preventing 5 Common MIG Welding Problems
Downtime and rework can be costly for manufacturing operations. The last thing any production team wants to do is the same work twice. If you add to that any time spent troubleshooting issues in the weld cell — the lost production time can start to accumulate quickly.
There are several steps operations can take to reduce the time lost to these common issues in MIG welding — and many of them start during weld setup and selection of consumables. Read on to learn more about five common causes of lost productivity in the weld cell and how to prevent them.
Cause 1: Poor fit-up or weld prep
Before welding even starts, pay attention to proper fit-up and joint design, as well as base material preparation and cleaning. Good fit-up means avoiding large or inconsistent gaps between the parts. Choosing the right wire size and gas mixture and matching those in advance can help optimize performance and provide proper gap filling capabilities.
Certain welding wires, such as metal-cored wires, are usable on less-prepped base material by offering the ability to weld through mill scale or other surface impurities. They also offer good gap bridging. If operations are often getting parts that aren’t thoroughly cleaned, it may be worth testing a metal-cored wire. Otherwise, changes to the weld prep stage of the operation may be necessary to achieve better material condition prior to welding.
Cause 2: Incorrect parameters or system setup
Using the wrong parameters or setting the wire feeder up incorrectly are common causes of lost productivity. Having the wrong settings can greatly affect the weld, sometimes without the operator even realizing the impact that a setting change can make. It’s important to have a thorough understanding of the wire feeder and all of its functions to set it up for optimal performance.
When properly set up, there should be very few issues with the performance of the MIG welding gun. However, if the system is set up incorrectly or there is a poor weld circuit, it can lead to contact tip failure, since the contact tip is the smallest fuse in the weld circuit. This can result in money wasted on frequent contact tip changeover.
Cause 3: Improper liner installation
MIG gun liners can wear out over time and must be changed periodically, like other consumables. However, replacement liners are often longer than necessary and must be precisely trimmed according to the style and length of the gun. If a liner is cut too short, it can result in issues like burnback, an erratic arc and wire chatter. When liners are cut too long, it can cause the wire to weave and curve as it feeds through the gun.
With either too-long or too-short liners, the result is often poor wire feeding and downtime spent troubleshooting these problems. Maintenance and troubleshooting for liner issues can be costly, resulting in multiple hours per week lost for an operation.
The more that liner movement within the gun can be minimized, the better your wire feedability will be. To avoid the guesswork and hassle, look for a solution that makes liner installation and trimming easier. The Bernard® AccuLock™ S consumable system affixes the liner at both ends of the gun, so welders are assured the liner won’t pull back or push into the contact tip, allowing for smooth, uninterrupted delivery of the wire to the weld pool.
It’s also important to occasionally check to make sure the liner is clear and not blocked by debris or buildup.
Cause 4: Loose connections or neglected maintenance
When MIG welding consumables aren’t properly installed and maintained, it can result in wire feeding issues and weld quality problems that lead to lost time for troubleshooting.
For example, a loose connection in the weld circuit means you’re not getting the power you expect from the power source. In that case, the operator may keep adjusting the parameters, causing an increase in resistance that leads to shortened consumable life. These issues tend to show up first in the contact tip. This is often the first thing the operator changes if they think they have a problem with their MIG gun. Changing the contact tip — even when the real source of the problem is a loose connection or improper setup in the circuit — drives up consumable costs and wastes time.
Be sure to periodically check and tighten all connections and cables. Tight connections help optimize performance and reduce the chance of issues occurring in the system.
Cause 5: Cutting corners with contact tips
Another cause of lost productivity is using low-quality contact tips. Some contact tips are designed for ease of use and high performance. They provide better arc starts, less spatter, more consistent welds and longer life.
With Bernard AccuLock S consumables, 60% of the contact tip is buried in the gas diffuser to protect it from heat damage. As the shielding gas flows through the gun, it cools the contact tip tail inside the gas diffuser. This helps reduce heat and wear. This also differs from traditional tips that screw onto the gas diffuser with little to no portion of the tip exposed directly to the shielding gas as it exits the diffuser to the arc. The tapered design of the consumables tightly locks the conductive parts together to minimize electrical resistance and further reduce heat buildup. The contact tips also feature coarse threads, making them less likely to become cross-threaded.
Troubleshooting common welding problems
Common problems in the weld cell — from poor fit-up or wire feeding issues to using the wrong consumables for the job — can cost the operation significant time and money. Addressing the causes of lost productivity often starts with proper weld prep and setup, as well as making sure the chosen consumables are right for the application. Optimizing setup and efficiency in the weld circuit makes troubleshooting that much faster when issues do arise.
Manufacturer Cuts $45,000 of Costs With New MIG Welding Guns and Consumables
Manufacturer Cuts $45,000 of Costs With New MIG Welding Guns and Consumables
General Kinematics — a premier manufacturer of vibrating equipment for processing bulk materials — has been providing consistent, on-time and innovative solutions to its customers for more than 60 years. The company prides itself on offering rugged, cutting-edge equipment to manage difficult-to-process materials across the mining, resource recovery, bulk processing and foundry industries.
A reputation for design leadership and creating tailored technical advancements sets the company apart from the competition, as does its commitment to providing excellent service.
This 200-person, Crystal Lake, Ilinois-based company doesn’t have time for slowdowns, especially in the welding operation. In recent years though, General Kinematics noticed exactly that. It was experiencing repeated MIG gun breakdowns and excessive contact tip consumption that slowed production.
“Between costs and repairs and lost labor from the welders having issues that stopped their progress, we estimated around $45,000 a year in costs from these issues,” said Jason Jerik, plant manager at General Kinematics.
That’s when Jon Strug, the company’s maintenance tech, approached their welding distributor, Steve Schuette of Weldstar in Aurora, Illinois, for a solution. Schuette recommended a trial of Bernard BTB air-cooled MIG guns with AccuLock™ S consumables.
Considering the change
Problems with the water-cooled MIG welding guns at General Kinematics were at the heart of its need for a new solution.
“The guns were definitely our main issue with maintenance for Jon,” said Joel Jacobson, director of manufacturing. “It was tough to keep up to the demands of the hoses breaking, the wires breaking internally in the guns, tips burning out, liners and such.”
Jerik added, “The last time we calculated from a dollar standpoint it translated to about five to seven hours a week in lost time just with liner issues. It was that frequent.”
The team, along with Schuette, took a slow and thorough approach to testing the Bernard air-cooled BTB MIG welding guns and consumables, making sure that the products performed as expected. They worked first with some sample guns in standard sizes and leads and had different welders try them for a week each.
“We would test a week with one fitter, a week with one welder, and then we’d move them around to see what kind of acceptance we would get with them,” said Jacobson.
General Kinematics welds a variety of materials — from A-36 steel to AR-500 plate — in thickness up to eight inches and on a variety of joints. Welding operators also weld both large and small weldments and use different welding wire diameters. The guns and consumables needed to be versatile enough to manage these jobs and produce the quality needed to adhere to the American Welding Society (AWS) D.1.1 Structural Welding – Steel code. They also had to be the right equipment for the company’s welding operators.
Jacobson and Jerik regularly met with the welding operators to request feedback during the trial.
According to Jerik, welding operators saw noticeably less consumable consumption. However, they wanted to change the angle on the neck of guns to gain better access to some difficult joint configurations. They worked back and forth with Bernard to determine a different angle of the neck that suited their needs.
“We wanted to do a thorough run of testing and vetting out to decide ‘Is this the right product for us? Are we going to get that buy-in from our welding operators?’” he said.
Ensuring that welding operators liked the MIG welding guns and consumables was a critical part of the testing General Kinematics conducted. The company has a culture of empowerment and wanted its welding operators to be heard and to contribute their opinions.
“We think it’s important to get our welders involved early in the process,” said Jacobson. “Not everyone likes change, but getting them involved in testing up front can help show the long-term benefits.”
“I’m huge on that,” Jerik added. “I’d rather not force and push a change onto a team. I’d
rather them accept it and make it their own.”
After eight months of testing, processing feedback and making adjustments, General Kinematics made the decision to convert to the Bernard BTB air-cooled MIG guns and AccuLock S consumables.
The benefit of the investment
General Kinematics invested in 400-amp BTB air-cooled MIG guns for its 40 welding operators, as well as several 450-amp Bernard water-cooled guns — all with the same AccuLock S consumables. Bernard built the company a special neck for its water-cooled guns to provide better ergonomic access to typical weld joints, and these guns are the first of their kind ever to be configured with the AccuLock S consumables.
So, what finally sold General Kinematics on the Bernard products? In short, durability and performance.
The reduction in gun maintenance was key. Strug no longer has to contend with leaking water-cooled guns or liner issues that need fixing — and the new guns and consumables are less frustrating for the welding operators, who can now spend more time being productive.
“We have a whole lot fewer repairs. Before it was constantly, every month, seven guns I had to send out to get repaired or I had to repair them myself,” said Strug. “It’s a huge difference in quality — night and day.”
This durability and performance result from a combination of the rugged construction of the BTB air-cooled MIG guns — which were configured according to the handle, neck, trigger and cables the company needed — and the liner that is part of the AccuLock S consumables system.
Bernard designed the liner in the system for error-proof replacement by eliminating the need to measure it prior to installation. Instead of the liner loading from the back, like many competitive guns, the AccuLock S liner loads in the neck at the front of the gun and then locks in place so it can be trimmed flush with the power pin. This prevents the liner from being trimmed too short or too long.
“I like the liners,” said Strug. “They last a lot longer and I definitely like the quality of them.”
According to Jacobson, another selling point was that AccuLock contact tips run significantly cooler than the company’s previous ones so there is less consumption and downtime for changeover.
That’s due to the design of the tip and gas diffuser. Sixty percent of the welding contact tip is buried in the gas diffuser, which protects it from heat damage, and the shielding gas also cools the contact tip tail as it flows through the gun. AccuLock consumables have a tapered design that locks the tip, gas diffuser and nozzle tightly together to further reduce electrical resistance and lower heat buildup.
Jacobson likes the ability to reduce costs by having equipment that lasts longer. And both the air- and water-cooled MIG welding guns use the same AccuLock S consumables, which helps reduce inventory management.
The welding operators like that the guns and consumables run cooler and help reduce spatter, so there is less cleanup.
The long-term benefits
For General Kinematics, making the change to the Bernard BTB guns and AccuLock S consumables is just another way the company commits itself to quality. But there has been more to the conversion than that.
General Kinematics was able to gain a return on investment in approximately 12 to 14 months. And while there are still labor and equipment costs for gun and consumable maintenance, the conversion has eliminated the $45,000 in extra spending to address previous issues with the water-cooled guns.
The products have also helped its welding operators achieve approximately 10% more productivity by eliminating downtime. That’s important to the welding operators and to Jerik.
“When it comes down to it, do these products make their job easier? Do they make them more productive?”
The answer to both is yes.
How to Prevent 5 Common Welding Gun Failures
How to Prevent 5 Common Welding Gun Failures
Having the right equipment in the welding operation is important — and making sure it works when it’s needed is even more so.
Welding gun failures cause lost time and money, not to mention frustration. Like with many other aspects of the welding operation, the most important way to prevent this problem is education. Understanding how to properly choose, set up and use a MIG gun can help optimize results and eliminate many of the problems that lead to gun failure.
Learn about five common reasons MIG guns fail and how to prevent them.
Reason No. 1: Exceeding the gun rating
The rating on a MIG gun reflects the temperatures above which the handle or cable becomes uncomfortably warm. These ratings do not identify the point at which the welding gun risks damage or failure.
Much of the difference lies in the duty cycle of the gun. Because manufacturers can rate their guns at 100%, 60% or 35% duty cycles, there can be significant variances when comparing manufacturer’s products.
Duty cycle is the amount of arc-on time within a 10-minute period. One manufacturer may produce a 400-amp GMAW gun that is capable of welding at 100% duty cycle, while another manufactures the same amperage gun that can weld at only 60% duty cycle. The first gun would be able to weld comfortably at full amperage for a 10-minute time frame, whereas the latter would only be able to weld comfortably for 6 minutes before experiencing higher handle temperatures.
Choose a gun with an amperage rating that matches the necessary duty cycle required and the length of time that the operator will be welding. It’s also important to consider the materials and filler metal wire that will be used. The gun should be able to carry enough power to melt the filler metal wire cleanly and consistently.
Reason No. 2: Improper setup and grounding
Improper system setup can increase the risk of welding gun failure. It’s important to pay attention to not only all consumable connections within the gun, but also all connections in the entire weld circuit to optimize performance.
Proper grounding helps ensure the operator isn’t sending too much power to a restricted window for the power to travel through. Loose or improper ground connections can increase resistance in the electrical circuit.
Be sure to put the ground as close to the workpiece as possible — ideally on the table that holds the workpiece. This helps provide the cleanest circuit structure for the power to travel where it needs to go.
It’s also important to place the ground on clean surfaces so there is metal-to-metal contact; do not use a painted or dirty surface. A clean surface gives the power an easy path to travel rather than create obstructions that create resistance — which increases heat.
Reason No. 3: Loose connections
Consumable connections play an important role in gun performance. Consumables should be tightly secured to the gun, and all threaded connections should also be secure. It’s especially important to check and tighten all connections after a gun has been serviced or repaired.
A loose contact tip or gun neck is an invitation for gun failure at that spot. When connections aren’t tight, heat and resistance can build up. Also, be sure any trigger connect being used is working properly and provides constant power.
Reason No. 4: Damaged power cable
Cables can be easily damaged in the shop or manufacturing environment; for example, by heavy equipment or improper storage. Any damage to the power cable should be repaired as quickly as possible.
Inspect the cable for any cuts or damage; no copper should be exposed in any part of the cable. An exposed line of power in the weld system will try to jump the arc if it touches anything metallic outside of the system. This can result in a wider system failure and a possible safety concern.
Re-terminate the gun and make the cable shorter if necessary, removing any cable sections that have nicks or cuts.
Also be sure the power cable is the proper size for the power that the feeder is supplying to the weld gun. An oversized power cable adds unnecessary weight, while an undersized cable causes heat buildup.
Reason No. 5: Environmental hazards
The manufacturing environment can be harsh for tools and equipment. Take care of tools and equipment to help extend their useful life. Skipping maintenance or treating tools poorly can result in failure and reduced life.
If the welding gun is connected to a boom arm above the weld cell, make sure there are no areas where the gun or cable can be pinched or damaged. Set up the cell so there is a clear path for the cable, to avoid crushing the cable or disrupting shielding gas flow.
Using gun anchors helps keep the gun in a good position and the cable straight — to avoid excessive strain on the cable — when the gun isn’t being used.
Additional thoughts on MIG gun failures
Gun failures in water-cooled welding guns typically happen more frequently than failures in air-cooled gun models. This is primarily due to improper setup.
A water-cooled welding gun requires coolant to chill the system. The coolant must be running before the gun is started because the heat builds quickly. Failure to have the chiller running when welding starts will burn up the gun — requiring replacement of the entire gun.
Welder knowledge and experience regarding how to choose between these guns and maintain them can help prevent many of the issues that result in failures. Small issues can snowball into larger issues within the system, so it’s important to find and address problems with the welding gun when they start to avoid bigger troubles later.
Maintenance Tips
Following some basics tips for preventive maintenance can help extend the life of the welding gun and keep it operating smoothly. It also helps reduce the chances of reactive emergency maintenance that can take the weld cell out of commission.
Regularly inspecting the MIG gun can be an important part of reducing costs and gaining good welding performance. Preventive maintenance doesn’t have to be time-consuming or difficult.
Check the feeder connection regularly. Loose or dirty wire feeder connections cause heat to build up and result in voltage drops. Tighten connections as needed and replace damaged O-rings as necessary.
Properly care for the gun liner. Gun liners can often become clogged with debris during welding. Use compressed air to clear any blockages when wire is changed. Follow manufacturer’s recommendations for trimming and installing the liner.
Inspect the handle and trigger. These components typically require little maintenance beyond visual inspection. Look for cracks in the handle or missing screws, and be sure the gun trigger isn’t sticking or malfunctioning.
Check the gun neck. Loose connections at either end of the neck can cause electrical resistance that results in poor weld quality or consumable failures. Ensure all connections are tight; visually inspect the insulators on the neck and replace if damaged.
Inspect the power cable. Regularly checking the power cable is important to reduce unnecessary equipment costs. Look for any cuts or kinks in the cable and replace as necessary.
Republished from Welding Journal (August 2020) with permission from the American Welding Society (AWS). Click here to view the original article.
From Semi-Automatic to Automatic: Tips for Selecting a Welding Gun
From Semi-Automatic to Automatic: Tips for Selecting a Welding Gun
Choosing the right equipment for a welding operation is critical to achieving high weld quality and productivity while also eliminating costly downtime. And that includes welding guns.
In many cases, companies may have a mix of welding processes and guns. For example, in heavy equipment and general manufacturing, it’s common to have semi-automatic welding along with robotic welding. In oil and gas and shipbuilding applications, semi-automatic welding and fixed automation are prevalent. The combination of welding processes and equipment allows companies serving these industries to weld a variety of part volumes and sizes.
These process mixes, however, can pose challenges in terms of gun selection. That’s why it’s important to know the best welding gun features to look for to achieve the desired weld results — and the best efficiencies.
This article has been published as a web-exclusive on thefabricator.com. To read the entire story, please click here.
The Importance of Cutting a Welding Liner Properly
The Importance of Cutting a Welding Gun Liner Properly
Cutting a welding gun liner correctly is, first and foremost, a matter of proper training. For traditional systems, it’s critical that welding operators understand how to measure and cut the liner to the required length for the gun.
A MIG gun liner that has been cut either too short or too long can lead to a host of issues, most often poor wire feeding. That, in turn, can lead to weld quality issues and rework — both factors that contribute to unnecessary and costly downtime.
The Bernard® AccuLock™ S Consumable System can help eliminate installation issues. First, however, it’s important to understand the pitfalls of standard liner installation to understand the value of this solution.
The problem with welding gun liners
The position of the gun and power cable factors significantly into whether liner installation is successful. If the gun and power cable are twisted or coiled before the welding operator trims the liner, the liner can end up either too long or too short, due to how the cable is constructed.
The copper inside the power cable is wound around a central conduit in a helix or spiral. If the cable is twisted or coiled, it will grow or shrink based on how the copper helix is also twisted. Think of a spring — if it is twisted one way, it grows; if twisted the other way, it shrinks.
For this reason, it’s important to lay the MIG gun and cable straight to avoid any kinks that would lead to an incorrect reading when trimming the liner. Generally, longer power cables are more prone to twisting, so welding operators must take even more care when installing liners in them.
Welding operators may experience the following due to an improperly trimmed liner:
- Poor wire feeding
- Erratic arc
- Birdnesting
- Burnbacks
- Wire chatter
A new solution for welding gun liners
The Bernard® AccuLock™ System eliminates the need to measure when cutting the welding gun liner for replacement. The liner is locked into place by the power pin cap. It is then trimmed flush with the power pin at the back of the gun and power cable. It is still important to lay the gun and cable flat, avoiding twists.
The welding operator can conduct a visual check to determine the liner is in the proper place. This check isn’t possible with a traditional liner if it has been cut too short; the welding operator simply can’t see it under the nozzle and gas diffuser.
The AccuLock System reduces wire feeding issues through the gun, as well, since the liner is locked and concentrically aligned at both the power pin cap and contact tip. This dual lock helps ensure the liner won’t extend or contract as the welding operator changes positions and the power cable naturally bends. The result is the elimination of gaps or misalignments at the front and back of the gun for a flawless wire-feeding path.
As an added benefit, the concentric alignment of the liner reduces mechanical wear on the contact tip that could lead to burnbacks or keyholing, both of which shorten the contact tip life.
For more information please visit the AccuLock S consumables product page.
Tips for Improving MIG Welding
Tips for Improving MIG Welding
Maintaining quality, productivity and cost savings is important in any semi-automatic MIG welding operation, but the steps companies take to achieve those goals vary. Still, there is one constant: the value of skilled welders. They are at the heart of the operation and help ensure its success.
Having the right equipment and understanding how to care for it are also important, as is
revisiting the welding process regularly to ensure its efficiency. Companies should take care to watch for common pitfalls that could negatively affect their progress toward streamlining and improving their operation.
Consider these tips to help along the way:
Welder training
With the industry facing an anticipated welder shortage of 400,000 by 2024, providing training to new welders is critical to supporting a productive and profitable MIG welding operation. In many cases, employees being hired are entirely new to welding or only have limited experience. Learning best practices early on is necessary to achieve the best performance and avoid excessive downtime for troubleshooting.
Gaining good weld quality depends on welders knowing proper techniques like gun angle and gun travel speeds and the impact of welding parameters on the process. Even if a company sets lockouts that keep welding parameters within a specific range, it’s valuable for welders to understand the impact voltage, amperage, wire feed speed and shielding gas have on the application.
It’s also important to provide training on other best practices in the MIG welding operation, such as:
- Consulting a checklist for maintenance or equipment checks at the beginning and end of each shift. This can include items like securing weld grounding and checking for gun or cable damage.
- Understanding proper ergonomics to prevent repetitive stress injuries. Having welder input on gun handle types can help with this, too.
- How to correctly install consumables and at what frequency, along with how to identify the signs of contact tip wear.
- Keeping the gun uncoiled and untwisted while using it to help avoid liner movement, which typically leads to wire feeding problems.
- As part of training, encourage welders to be open to asking questions and offer refresher courses to keep skills in top shape.
Assessing the process
To support the long-term efficiency of a MIG welding operation, it’s a good idea to regularly assess each aspect of it.
Time studies, for example, offer excellent insight into the entire workflow and allow companies to record the amount of time each task takes to complete. These studies include a breakdown and analysis of parts handling, welding and more. By recording every activity in the operation, it is possible to see whether each one is adding value. If not, adjustments and re-sequencing can be made.
Analyzing the operation can also help identify the need for more welder training. For instance, if a significant amount of time is spent grinding after welding, it can indicate that there are issues contributing to overwelding or poor weld quality. The company can then take proactive steps for additional welder training to improve quality and reduce or eliminate the need for grinding and rework.
Similarly, if welders are spending more time transferring parts than they are welding or there are bottlenecks of parts entering the welding cell, that indicates the workflow needs to be adjusted. The goal is to minimize the amount of time welders spend handling or double handling parts and helps avoid parts from backing up or having welders sit idle waiting for them.
Improving the organization of the workstation as part of a general assessment can also help improve welding productivity. This could include adjusting welding tables and part racks to be more ergonomic so welders are more comfortable and can weld longer.
Welding gun selection and use
Having the correct MIG welding gun for the application can help enhance performance in a MIG welding operation.
One of the first things to consider is cost. Quality MIG welding guns carry a higher price, but they are worth it in the long term. A better gun (when used properly) lasts longer and can help improve weld quality and efficiency over time. Guns that feature mechanical compression fittings, as opposed to crimped fittings, are a good choice. They typically last longer from wear and tear and can also be repaired if damaged, which saves money on replacement guns.
Be certain to choose a gun with the appropriate amperage rating and duty cycle for the application to prevent overheating. A lower amperage MIG welding gun may be appealing to a welder due to its lighter weight and flexibility; however, it will not be able to withstand an application requiring higher amperages and long arc-on times.
Effectively grounding the weld circuit is another way to gain weld quality and productivity in a semi-automatic welding operation. It can also protect the welding gun from overheating and from wearing out consumables too quickly. Installing the ground clamp as close to the weld as possible and limiting the amount of connections can help to prevent one or more from coming loose over time or creating electrical resistance.
Always choose correctly sized ground cables for the weld circuit and the right type of ground clamp. A C-clamp is a good option as it is a tighter connection versus a spring clamp, which helps prevent arcing at the ground that could lead to an erratic arc. As with other quality components in a MIG welding operation, C-clamps can be more expensive, but they offer a connection that can better protect the gun and save on replacement or repair costs.
Lastly, take care to inspect the welding gun cable regularly for damage and replace as necessary. Nicks or cuts in the cable can expose bare copper, causing a safety hazard of electrical shock, as well as erratic welding issues. Adding a cable jacket cover is a proactive step in avoiding these problems.
The role of consumables and wire
Contact tips, nozzles, gas diffusers and liners all affect MIG welding performance. Ideally, select consumables and wire designed to complement one another as a system. These can help maintain solid connections that provide the best electrical conductivity and arc stability.
Always trim the liner properly — per the guns owner’s manual — to avoid erratic arcs and burn backs or look for liners that lock into place and require no measurement to avoid trimming them too long or too short.
For semi-automatic MIG welding, copper contact tips work well; however, if more tip life is desired or needed, chrome zirconium tips are an alternative to better resist physical tip wear (also known as keyholing). It helps to monitor how often contact tips are being changed to avoid straying too far from the originally planned frequency of tip changeover. If tip changes begin to increase drastically, then this points to incorrect installation of consumables, a liner being cut too short or other damage in the system. Monitoring consumables usage can also help identify when contact tips could still have life left in them. If contact tips are changed too early, this results in unnecessary downtime.
Also consider the wire being used. Quality is key here, too. Less expensive wires often have an irregular cast or helix or an inconsistent layer of lubricant. All of these factors can lead to weld quality issues and additional wear on the contact tips.
Keeping on track
Maintaining an efficient MIG welding operation takes time and resources, but it’s worthwhile to make an investment in welders and equipment to achieve the best results. Continue to monitor the process for improvement opportunities and engage welders whenever possible. Since welders are responsible for moving quality and productivity forward, their ideas can be a valuable asset.
How to Prevent Common Causes of Poor Welding Wire Feeding
How to Prevent Common Causes of Poor Welding Wire Feeding
Poor wire feeding is a common problem encountered in many welding operations. Unfortunately, it can be a significant source of downtime and lost productivity — not to mention cost.
Poor or erratic wire feeding can lead to premature failure of consumables, burnbacks, bird-nesting and more. To simplify troubleshooting, it’s best to look for issues in the wire feeder first and move toward the front of the gun to the consumables.
Finding the cause of the problem can sometimes be complicated, however, wire feeding issues often have simple solutions.
What’s happening with the feeder?
When poor wire feeding occurs, it can be related to several components in the wire feeder.
1. If the drive rolls don’t move when you pull the trigger, check to see if the relay is broken. Contact your feeder manufacturer for assistance if you suspect this is the issue. A faulty control lead is another possible cause. You can test the control lead with a multimeter to determine if a new cable is needed.
2. An incorrectly installed guide tube and/or the wrong wire guide diameter may be the culprit. The guide tube sits between the power pin and the drive rolls to keep the wire feeding smoothly from the drive rolls into the gun. Always use the proper size guide tube, adjust the guides as close to the drive rolls as possible and eliminate any gaps in the wire path.
3. Look for poor connections if your MIG gun has an adapter that connects the gun to the feeder. Check the adapter with a multimeter and replace it if it’s malfunctioning.
Take a look at the drive rolls
is the wrong size for the wire being used.
Using the wrong size or style of welding drive rolls can cause poor wire feeding. Here are some tips to avoid problems.
1. Always match the drive roll size to the wire diameter.
2. Inspect drive rolls every time you put a new spool of wire on the wire feeder. Replace as necessary.
3. Choose the style of drive roll based on the wire you are using. For example, smooth welding drive rolls are good for welding with solid wire, whereas U-shaped ones are better for tubular wires — flux-cored or metal-cored.
4. Set the proper drive roll tension so there is sufficient pressure on the welding wire to feed it through smoothly.
Check the liner
Several issues with the welding liner can lead to erratic wire feeding, as well as burnbacks and bird-nesting.
1. Be sure the liner is trimmed to the correct length. When you install and trim the liner, lay the gun flat, making certain the cable is straight. Using a liner gauge is helpful. There are also consumable systems available with liners that don’t require measuring. They lock and concentrically align between the contact tip and power pin without fasteners. These systems provide error-proof liner replacement to eliminate wire feeding problems.
2. Using the wrong size welding liner for the welding wire often leads to wire feeding problems. Select a liner that is slightly larger than the diameter of the wire, as it allows the wire to feed smoothly. If the liner is too narrow, it will be difficult to feed, resulting in wire breakage or bird-nesting.
3. Debris buildup in the liner can impede wire feeding. It can result from using the wrong welding drive roll type, leading to wire shavings in the liner. Microarcing can also create small weld deposits inside the liner. Replace the welding liner when buildup results in erratic wire feeding. You can also blow compressed air through the cable to remove dirt and debris when you change over the liner.
Monitor for contact tip wear
Welding consumables are a small part of the MIG gun, but they can affect wire feeding — particularly the contact tip. To avoid problems:
1. Visually inspect the contact tip for wear on a regular basis and replace as necessary. Look for signs of keyholing, which occurs when the bore in the contact tip becomes oblong over time due to the wire feeding through it. Also look for spatter buildup, as this can cause burnbacks and poor wire feeding.
2. Consider increasing or decreasing the size of contact tip you are using. Try going down one size first, which can help promote better control of the arc and better feeding.
Additional thoughts
Poor wire feeding can be a frustrating occurrence in your welding operation — but it doesn’t have to slow you down for long. If you still experience problems after inspecting and making adjustments from the feeder forward, take a look at your MIG gun. It is best to use the shortest cable possible that can still get the job done. Shorter cables minimize coiling that could lead to wire feeding issues. Remember to keep the cable as straight as possible during welding, too. Combined with some solid troubleshooting skills, the right gun can keep you welding for longer.
In today’s marketplace, companies continue to automate portions, if not all of their welding operation. The reasons are many: to address a shortage of skilled labour, to improve quality, to decrease waste and rework, and/or to increase productivity — in short, to seek benefits that provide a competitive edge. Not all companies, however, are successful in the process. Those beginning without a well-thought-out roadmap risk losing valuable time during implementation and operation and may miss the full benefits provided by a robotic welding system. Conversely, companies that begin with a careful examination of their welding needs and existing processes — and develop a detailed plan with clearly established goals — are more likely to achieve success. Planning should include an accurate assessment of parts, work flow and the current facility, as well as an evaluation of the potential return on investment (ROI). Companies should not only look at current needs, but also consider future opportunities to determine the best robotic welding system to scale for potential growth or changes to products they may produce later. In an economy where orders are increasing and welding positions are hard to fill, robotic welding can help maintain or increase productivity. In a semi-automatic welding operation, labour accounts for approximately 70 to 85% of the total cost of welding a part. A robotic welding system can reduce that cost and increase throughput by completing the work of two to four people in the same amount of time — however, companies still require skilled welding operators to oversee the robotic cell. 1. With the right robotic welding system, companies can improve first-pass weld quality and reduce the amount of rework or scrap parts. Depending on the welding wire and mode used, the system may also minimize or eliminate spatter, which reduces the need to apply anti-spatter compound or perform post-weld clean up. 2. A robotic welding system can reduce over-welding, a common and costly occurrence associated with the semi-automatic process. For example, if a company has welding operators who weld a bead that is 1/8-inch too large on every pass, it can potentially double the cost of welding (both for labour and for filler metals). Over-welding may also adversely affect the integrity of the part. 3. Companies can reallocate skilled employees to other production areas to fill open positions and gain additional productivity and efficiencies. 4. Welding automation can also provide a competitive advantage as it may be considered attractive to customers. The improvement in quality may prompt new customers to place orders or lead existing customers to increase their orders with the objective of growing their own businesses. 5. Finally, robots are fast. They don’t have to weld all day to be profitable. That fact improves productivity and the bottom line by making the same number of parts as in a semi-automatic process in less time. When considering an investment in a robotic welding cell, companies should have part blueprints, preferably in an electronic format. Without a blueprint, the part likely won’t meet the basic criterion necessary to ensure repeatability during the manufacturing process. A robotic welding system welds in the same place every time. When a part’s tolerances are unable to hold its position — if there are gap and/or fit-up issues — the company will simply be automating a broken process. This can increase rework or scrap. If a company currently relies on its welding operators to compensate for fit-up issues, it will need to look upstream in the manufacturing process to establish consistency. What processes need to change so these welding operators send uniform parts downstream? Or, if vendors supply the parts, can they guarantee consistency? A streamlined workflow is one of robotic welding’s benefits. To achieve it, companies need to look beyond the weld cell, making certain the facility can accommodate a smooth flow of materials. It makes little sense, for example, to invest in a robotic welding system to increase productivity, but then place it in a corner where employees may have to handle each part multiple times. There should be a consistent supply of parts to avoid moving a bottleneck from one area to another. It is also important to look at the expected cycle time of the robot. Can personnel supply parts to keep up with the demand of the robot’s cycle time? If not, the supply of parts, including where the company stores them and how it moves them, will need to be adjusted. Otherwise, a robot will sit idle waiting for components to come down the line. There is no single welding automation solution that is best for every company. When a company is considering the investment, it should factor in the expected lifetime of the job, the cost of tooling and the flexibility the equipment offers. Fixed automation is the most efficient and cost-effective way to weld parts with simple, repetitive, straight welds or round welds, where the part is rotated with a positioner. If a company wants to reuse the equipment when the current job ends, however, a robotic welding system offers more flexibility. A single robot can store programs for multiple jobs, so it may be able to handle the tasks of several fixed-automation systems. There is a certain volume of parts that justify the investment of welding automation for each company. An accurate assessment of goals and workflow can help determine what that volume is. If a company makes only small runs of parts, robotic welding becomes more challenging. But, if a company can identify two or three components that can be automated, a robot can be programmed to manufacture those parts, offering greater versatility and boosting productivity. This may benefit even small companies that may not have significant volume of a single part. Although a robot is more expensive than a fixed-automation system, it is important to consider the cost of the tooling before deciding between the two. Fixed automation systems can become quite expensive if they require extensive changes to retool a new part so it can be welded consistently. The physical footprint for a robotic welding system and the area needed for parts to flow into the welding cell is typically greater than that of a semi-automatic welding operation. The available space needs to be adequate for the robot, welding power source and other equipment. This helps minimize the need to customize products, such as cables, nozzle cleaning stations (or reamers) or the robotic MIG gun to fit the work envelope. A company with less space can still make welding automation work. One option is to purchase fewer pieces of robotic welding equipment that are capable of performing multiple tasks, such as material handling or vision/scanning systems. A third-party integrator can help determine whether a facility suits the installation of a robotic welding system. System integrators are knowledgeable about facility modifications, including important safety regulations that apply in a company’s region, country or state — in addition to those specified by OSHA and RIA (Robotic Industries Association). In addition to offering advice on facility modifications and helping a company select the right robot, a robotic systems integrator or welding automation specialist can: 1. Help determine if parts are suitable for automation, and, if not, what is required to make them suitable 2. Analyze the workflow and facility to identify potential roadblocks 3. Analyze the true costs involved with the investment, including facility updates and tooling 4. Determine the potential payback of the investment 5. Help identify goals and develop a precise plan and timetable to achieve those goals 6. Explain automation options and help select those that best fit the company’s needs 7. Help select a welding equipment that has the flexibility to maximize travel speed, minimize spatter, eliminate over-welding, provide great arc stability and increase first-pass weld quality Integrators can also help select additional equipment for the robotic welding cell, including positioners, tooling, the robotic MIG gun, welding wire and peripherals. Each item serves a distinct function. The positioner turns, rotates or otherwise moves the part into an optimal position for welding. In many cases, this involves moving the part so that the system can weld in a flat position for optimal deposition efficiency. A positioner can also allow for coordinated motion between the robot and weldment. The tooling holds the part in place during welding and is a critical component of a robotic welding system. The robot arm and robotic MIG gun travel a programmed path each cycle. If the weld joint is out of place because the part is misaligned, it can result in inadequate fusion or penetration and rework or scrap. It is important to design the tooling correctly upfront when investing in a robotic welding cell and monitor it for mechanical wear or heat distortion once it has been put into operation. This helps ensure consistent part fit up so that weld quality doesn’t suffer. The robotic MIG gun should never be an afterthought when considering an investment in welding automation, nor should the welding wire. Both can have a significant impact on productivity and profitability. An integrator can help with the selection based on how the gun and wire perform in conjunction with the rest of the system’s components. The gun will be subject to intense heat and spatter, so it must be durable. It also needs to be the appropriate size to maneuver around the tooling and gain proper joint access. Finally, peripherals, such as reamers, an anti-spatter sprayer and wire cutter are good options to discuss with an integrator prior to making the investment in welding automation. These devices can improve uptime and welding performance by keeping the welding gun consumables free of spatter, operators out of the weld cell and providing consistent wire stickout during welding. Companies cannot simply purchase a robotic welding system and let it go. They need a welding operator or other employee skilled in robotic welding programming. This will likely involve additional training to upgrade his or her skill sets. The good news is, programming a robot today is much quicker than in the past. Simplified teach pendants, along with the availability of desktop programming, help expedite the process and reduce downtime. Despite the ease of programming, however, companies may need to alleviate some existing tasks to allow time for the employee to oversee the robotic welding cell without becoming overloaded with too many responsibilities. Most robot OEMs offer a weeklong training course explaining how to operate the equipment. This course, followed by a week of advanced programming, is recommended when implementing welding automation. If the personnel investigating the prospect of robotic welding determine it’s a good fit, they will likely need to justify the investment to upper management or an owner. Calculating the potential payback is essential. There are several steps to consider. First, determine whether the volume of parts the company needs to produce requires the speed of welding automation. Remember, the key benefit of a robotic welding system is the ability to produce high volumes of quality welds or in smaller facilities to offer the flexibility to weld smaller volumes of multiple parts. Calculate payback by assessing the current volume of semi-automatic parts and cycle times. Compare these to the potential cycle times of a robotic welding system. Again, an integrator or welding automation specialist can help. Establishing the comparison is critical to estimating the potential return on investment. That said, even if a company will produce the same number of parts with a robot, it could justify the investment by the amount of labour it can reallocate elsewhere in the operation for jobs that boost production, eliminate bottlenecks or increase quality. For example, a company could utilize the skills of semi-automatic welding operators to complete challenging welds that are too complicated for a robot to manage. It’s important to factor the bulk cost of shielding gas and welding wire when looking at the potential payback. While there is an initial cost for a shielding gas/manifold system, it can help optimize a company’s robotic welding capabilities in the long term by minimizing downtime for cylinder changeover. The same is true for welding wires. The larger drums — typically ranging from 500 to 1500 pounds — can further reduce costs in a robotic welding cell since they require fewer changeovers and often come with purchasing discounts. Companies need to keep in mind that the benefits of robotic welding can be significant. However, those benefits come at an upfront price. Many companies, especially smaller ones or those that frequently change production lines, need a faster payback — no more than 12 to 15 months is common to justify the investment. If a company will have the same production needs for many years, it can typically justify a longer payback period. Management and owners should discuss their payback goals with a trusted robotic welding integrator as part of the assessment process.
Robotic welding systems continue to gain in popularity due to their ability to increase productivity, improve quality and decrease costs in the right application. But they also offer a way to address a shortage of skilled labor for manual operations. Welding automation provide companies with a means of staying competitive in a demanding marketplace, while using their existing and potential workforce to oversee the weld cell. With more and more robotic welding systems being implemented — the Robotics Industries Association (RIA) cited that 20% of all industrial applications had robotic welding cells as of 2017 — comes the need for increased attention to safety. From the robotic welding gun and peripherals to the robot itself, following safety best practices is essential. Statistically, welding automation is safer than manual or semi-automatic welding. However, operators overseeing the robotic welding cell must still remain vigilant. This is particularly true when performing nonstandard operations; these include programming, maintenance and any other tasks that involve direct human interaction with the robot. Conducting a thorough welding risk assessment helps identify potential safety hazards associated with a specific robotic welding system (whether it is a pre-engineered or custom cell) and is a critical first step in establishing a safer welding environment. This assessment provides a baseline for implementing solutions for identified risks and establishing appropriate welding safety training. In addition, it helps companies maintain compliance with safety standards, which most importantly protects employees but also protects the bottom line. Noncompliance and/or safety violations that can lead to injury become can be costly in terms of fines and workers’ compensation. Companies can obtain welding safety resources through the American Welding Society (AWS), including Safety in Welding, Cutting, and Allied Processes, ANSI Standard Z49.1, a free download at aws.org. The National Fire and Protection Association (NFPA) also offers resources. RIA follows American National Standards Institute (ANSI) standards and offers safety seminars and webinars. RIA also provides information on industrial machinery and guarding, as well as guidelines to help companies, including the American National Standard for Industrial Robots and Robot Systems – Safety Requirements, ANSI/RIA R15.06-2012. The Occupational Safety and Health Administration (OSHA) is another valuable safety resource. Many robotic welding integrators or robotic welding system manufacturers offer training for the safe use of their equipment, including how to test safety functions and at what frequency. They also provide manuals and safety standards for their systems. It is critical to read and follow these thoroughly. Manufacturers of robotic MIG welding guns often integrate design elements into these products to aid in their safe use. These elements are intended to protect operators during routine maintenance and minimize or eliminate the need to enter the weld cell to complete tasks. For example, guns that are compatible with front-loading liners help improve safety in a robotic welding cell. These liners can be installed from outside the weld cell — there is no need to climb over tooling or maneuver around the robot to complete replacement. Operators or maintenance personnel also don’t need to remove electrical connections to replace components during the process. An insulating disc is another important safety feature in select guns. It helps protect operators from the welding current during maintenance and protects the robot from the current, limiting potential damage. In addition to integrated safety features, there are some key best practices for working with robotic welding guns, consumables and reamers (or nozzle cleaning stations). First and foremost, always de-energize the robotic welding system when installing a robotic MIG gun or consumables, and follow all lockout/tagout procedures. When possible, it’s ideal to have a window or opening that allows consumables to be changed or inspected from outside the weld cell. When possible, it’s ideal to have a window or opening that allows consumables to be changed or inspected from outside the weld cell. If this isn’t feasible, programming the robot to stop near the weld cell door simplifies consumable changeover and eliminates the need for the operator to enter the cell, maneuver around tooling or climb on anything to complete the job. The appropriate personal protective equipment (PPE) is also important when changing over consumables or the welding wire. The nozzle and contact tip may be hot, and there is the risk of the welding wire puncturing the operator. Leather or other thick work gloves are a must, and safety glasses should be worn at all times. Always use the proper tool to change over the nozzle and contact tip. We recommend a pair of welpers. When performing maintenance on a reamer, begin by resetting the equipment to a home state, de-energizing it and following lockout/tagout procedures. Be certain there is no supply of air or electricity to the reamer. When changing over cutter blades, always wear gloves and use two wrenches to remove and install them. Reset the reamer to a home state when finished. This is an important last step, as the reamer will automatically complete a cycle as soon as it receives a start signal and is reenergized. Welding operators and maintenance personnel should familiarize themselves with the emergency stops on a robotic welding system as a first safety step. The number and location of these stops varies by system. For example, welding cells typically have an operator station emergency stop that ceases all robot functions and turns off the robot servo power, along with an emergency stop on the teach pendant. Operators should test these emergency stops periodically, although testing too frequently is stressful on the mechanics of the robotic welding system. Understanding brake release procedures is also critical. RIA sets standard requirements for these; however, every robotic welding system is different, and the location of the override buttons may vary. As when interacting with a robotic MIG welding gun, consumables or reamer, always follow proper lockout/tagout procedures before entering the robotic welding cell. Many systems have multiple lockout/tagout locations that are indicated by stickers. Some pre-engineered welding cells feature sliding programming access doors with magnetic keys that indicate that they are fully open and ready to be locked out prior to maintenance, helping to prevent pinch points or a trap hazard. A built-in awareness barrier in pre-engineered cells is another means of aiding operator safety. This hooped barrier inside the weld cell covers the sweep area of the indexing table. Its purpose is to protect the operator from pinch points during teaching operations by separating the him or her from the space between the robot and the wall of the weld cell. For robotic systems that are not enclosed, guards around the cell are necessary. These can take the form of physical barriers, like perimeter fencing or light curtains and/or electronic guarding such as area scanners that stop the robot when an operator is present in a specific area of the system. Lastly, robotic integrators and robotic welding system manufacturers provide risk assessment documentation, typically in the operator’s manual. It is important to review this assessment thoroughly and train employees on the proper techniques to mitigate any identified risks. For example, programming the robot introduces mechanical hazards such as the potential for pinching or impact, which can be addressed by standing a safe distance outside of the weld cell or by using a slower teach speed if offered on the teach pendant. In addition to the best practices outlined for robotic MIG welding guns, consumables and systems, there are steps to further protect employees. Safety in welding automation should be top of mind among operators, management and maintenance personnel. Ongoing training needs to be a priority, whether it is conducted through company programs or seminars offered by outside resources. The goal is to ensure that everyone involved with the robotic welding system is playing an active role in employing best practices. When following them properly, the result is a safer work environment and a stronger bottom line.
How to Successfully Implement a Robotic Welding System
How to Successfully Implement a Robotic Welding System
Why robotic welding?
In addition, the national and international marketplace has become increasingly competitive, with companies seeking contracts from any number and any size of business. Investing in welding automation can help set up a company on the path to compete at a global level.Here are additional benefits:
Repeatability is key
Assess the workflow
Robotics or fixed automation?
Consider the available space
Integrators and equipment selection
Employee training
Justifying the expense and calculating payback
Improving Welding Automation Safety With Risk Assessment and Training
Improving Welding Automation Safety With Risk Assessment and Training
Robotic welding safety hazards and resources
External Resources
Safe use of robotic welding guns, consumables and reamers
Personal Protective Equipment (PPE)
Navigating the robotic welding cell safely
Unenclosed Robotic Systems
Other safety considerations
Creating a culture of safety
