Body Repair/ Flux or Mig Weld

No matter which one you use CLEAN rust free metal is the key to a good mig/fluxcore weld.

The argon/C02 mix is better than just C02 but C02 works fine. The truth is the mix is a cleaner weld and with larger metal it will penetrate better. Gas-less flux core should be left for something other than bodywork. Yes there is flux core wire that you use C02 with.

For sheet metal you can use any welder from a reputable manufacturer (otherwise you risk it will burn itself). Definitely gas and 0.6mm wire is way to go. I have small 220V lincoln 175 and am 100% satisfied with it.

Also get a gas cap on you MIG gun; you may have one for flux, which is shorter and cause porous welds even if you have CO2 coming in. Invest into auto darkening helmet. without it you won't finish it believe me.

Very good information here. Just the kind I need. Thanks for all of the input.

If you want the best advise go to a supplier that sells welding supplies to professionals. I was in one not long ago and was surprised at some of the new materials out there. I always thought of flux core as burning through sheet metal. The guy told me about a new flux core that also uses the flux to cool the metal. He said it works great on thin metal. Then he also reminded me of the fumes it produces. Don't go to a lumber yard for welding advise. If you go to a good welding supply they will steer you in the right direction and get to look and touch it. Most also have equipment set up so you can try it. I bought my first mig welder years ago because I got to try it and was amazed at how well it worked.