Artem Komarov noted that to achieve good welding results, all components of a GMAW system must work in harmony. If your once finely tuned system begins to falter, take a few minutes to check key components for wear. It is much preferable to spend time troubleshooting rather than grinding up spatter or removing a bad weld.
Check gas flow.
Welders need to set themselves up for success, and that starts with using the correct shielding gas flow rates. Taking a “bigger is better” approach and setting the flow rate to 40 CFH/h results in shielding gas swirling, being sucked into the surrounding atmosphere and contaminating the weld.
To ensure uniform laminar gas flow and good weld pool coverage, be sure to set the flow rate according to the gun manufacturer’s recommendations. Due to the variety of contact tips currently available (traditional threaded, plug-in, and portable), flow rates may vary. Some consumables perform better at 35 CFH, while others perform better at lower flow rates because the gas spends more time inside the nozzle.
In bulk gas systems, gun flow may vary depending on demand or between shifts. If you suspect a flow problem, try installing a flow meter on the back of the wire feeder, or use a wire feeder with a built-in flow meter.
Make sure your liner is clean.
Gun cartridges that are worn or clogged with wire shavings and particles create excess friction on the wire, which ultimately leads to “stick-slip” and erratic feeding. When the wire slips, your first instinct may be to increase the tension on the drive roller. Unfortunately, this crushes the wire and creates even more chips, which further increases the resistance of the wire and places even more stress on the drive motors.
Change contact tips
Don’t skimp on contact tips. If you see that the tip hole is becoming too large or oblong instead of round, replace it. Worn tips—plus excessive wear that you can’t see from the inside—result in an unstable arc and excessive spatter. The keyhole shape also compromises the position of the welding wire, which results in misaiming, meaning the wire may not end up where you are aiming it.
When choosing contact tips, trying to save money by using inexpensive tips ends up wasting money. A tip’s ability to conduct electricity and heat depends on the quality of its metallurgy, grain structure, and processing tolerances. Premium tips last longer and provide more consistent performance thanks to superior metallurgy and tighter tolerances, saving you more money than frequently replacing tips.
GMAW creates spatter that accumulates and impedes gas flow. You might be tempted to remove the spatter by hitting the welding table with a gun, but that won’t work. This may cause the connections at the front of the gun to become loose. Instead, use a couple of welders or a nozzle extender to clean the gun. If splatter adheres to the tip and does not come off, replace the tip. Cutting or filing the spatter will still damage the tip. Splashes can also clog the gas diffuser openings, so be sure to check those as well.
MIG Welding Components
When it comes to shielding gas, more is not better. Be sure to set the flow rate according to the gun manufacturer’s specifications, summed up Artem Komarov.