Common MIG Welding Issues, MIG Welder Machine Gunning

Common MIG welding issues. MIG: Popping and spatter.“Machine gunning” is the stuttering effect seen and felt usually at the beginning of a MIG weld while the arc is being struck. This is possibly a result of several factors that may be present. One of the primary causes is holding too long of a standoff as the arc is struck. Usually this happens as one tires, or from trying to lift the nozzle too high to see the puddle. The wire will then begin to stutter or pop with intermittent arc flashes as the wire tries to burn back to adjust to the short circuit. This can also happen by holding too loose of a grip and allowing the force of the wire to “push back” the nozzle back when it first strikes the metal. A chain reaction begins as the nozzle bounces forward after the wire burns back as the hand naturally pushes it forward. This is not unlike holding too light of grip on a semi-automatic pistol when firing. It can either misfire, or “accidentally” fire off several rounds if the grip is not firm and able to handle the recoil. Usually this is a problem with beginners as they are either surprised by the arc start or not used to the pushback that will be felt as the arc is struck. They key to correcting this problem is to establish a standoff of around 3/8” inch and firmly grasp the gun, supporting your arm if necessary and gently pull the trigger. If the gun begins to push back on you, push it forward consciously with a firmer grasp. Do not let it push the nozzle of the gun away from the weld. If you do this and the machine gun continues, the arc does not want to establish, and/or the wire begins to curl up without melting or even pops irregularly as it is fed, then it is likely that you do not have enough voltage to match the speed of the wire. Increase the voltage by 1 volt and test again until the arc establishes well and the feed rate feels constant as the puddle develops. If you do not have full control of the voltage, as with tap type transformer welders, step up to the next “click” or notch on your scale and see if it fixes the problem as it will give you a higher voltage. Continue to do so until the arc is striking and burning smoothly.Everlast Power Equipment, your MIG welding experts.Learn more on our welding forum