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

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

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.