MIG welding is an art. And in order to become great at it, you’ll need lots of practice, plus an understanding of how it works. It also helps to know what might be going wrong if your welds aren’t quite studio-ready. To help you get there, we’ve rounded up some tips and tricks to overcome the most common problems with MIG welding. (If you’re new to MIG welding, make sure you’re starting out on the right foot by reading our blog on setting up your MIG welder.)
Setting the Bar
So what are we aiming for with a great MIG weld? Ultimately, the goal is total metal fusion. The weld needs to be strong and join the two pieces of metal firmly together without warping or burning through them. Appearance will vary depending on the type of weld you’re doing, material, etc., but overall it should have consistent, even ridges like a stack of dimes; have very little splatter; and not be too thick or too thin. If your weld isn’t quite right, there are several things that might be happening:
Improper settings: Voltage, wire feed speed and gas flow rate can all be adjusted on your welder, and requirements vary based on metal thickness and whether you’re welding aluminum or another material. If something doesn’t look quite right, check to make sure you’re using the correct settings recommended on the welder. Some machines, like the Chief MultiMig 522 and 511, offer preset weld programs that help you get going correctly the first time. When you know you have the settings right, you can start to correct other things that might be going wrong.
Going too fast: Getting the speed right is key. If the gun travels too fast, you’ll have a thin, convex or even spotty and spattered weld because you’re not putting down enough wire to create that nice even bead.
Traveling too slow: If you go too slow, the weld will be too large, could damage the metal and may not fuse properly. When you’re pushing or pulling the gun at the right speed, you’ll hear a consistent crackle – like cooking bacon – and you’ll have secure sturdy fusion. Practice makes perfect here, so just keep at it.
Improper stickout: Having more than about ¾ to ½ of an inch of wire sticking out of the gun when you start can cause problems from the beginning and lead to an uneven weld that might have pools and spatter. To avoid this, check the length of the wire before starting and trim or extend as needed. Also check the contact tip and gun nozzle. If spatter has built up, replace the tip and/or clean off the nozzle.
Inadequate grounding: If your welder seems to be working improperly or inconsistently, one of the first things to check is your grounding clamp. In order to function, the machine needs a steady flow of electricity through a complete circuit. To achieve that, make sure the clamp has full contact on a clean area.
The wrong equipment for the job: Make sure your machine is up for the job. For instance, if you’re working on aluminum, you’ll want a welder with a push-pull wire feed system. This will keep the softer wire used with aluminum from tangling and creating a big mess.
Working with a MIG welder gets easier every time you use it. Keep practicing and correcting, and you’ll get those nice even beads you’re looking for.