Will the MIG weld stainless? I hope to fabricate my own exhaust next off season.
There are just some things that you have to come to terms with when using a mig. Welding thin wall mild steel, ( like exhaust tubing) can be accomplished with a mig. If you use a thin wire, have your heat set right, and pulse trigger the gun, you get a weld that looks like the one I posted above, except it will stand on top of the joint because you're butt welding pieces together. If you can achieve that look, Despite the " stacked nickels" appearance, Most would elect to grind that down in order to have a seamless appearing joint.
Now,...throw in aluminum, or stainless.
Stainless can be mig welded, but why would you? Stainless doesn't like the excessive heat mig welding can generate and can become brittle when mig welded. Starting off not knowing how to weld, attempting to learn how to TIG, and then going out and using thin wall stainless to learn on is gonna be like a 1 year old baby attempting to run the Boston marathon.
There's gonna be a lot of crying, a bunch of mess, what's not messy wil be ruined, and it's gonna take forever.
Stainless is about the biggest pain in the ass to fabricate going.
It's 3-5 times more expensive
It's a pain in the ass to cut/ drill/ grind, will kill standard drill bits, and saw blades, and will wear out standard flap discs much faster than when used on mild steel.
Grinding on it will show the " tooth marks" of the disc you used to grind on it, requiring even more grinding to smooth it out, and it's already way thinner than the standard tubing to start with.
But,....if you master the TIG process, you don't touch the weld,..you want it visible. And nothing looks better than a TIG welded set of stainless headers.
There's just no way in hell anybody jumps from "a to z" w/o dozens of hours spent welding with a TIG. Anybody who can write their name legibly can learn to mig in a week.