Hey guys,
I have just started learning to weld with wire feed. I have a millermatic 174 running argon and .30 wire. I have successfully welded metals from 1/16 to 1/4 using various voltages and wire speeds.

My question is, What settings and wire thickness do I need to weld automotive thickness sheet metal? I want to start boxing up my Mustangs subframe and really don't want to make slop or holes in the body.

I have done panel replacement and repair by brazing but not with MIG.