floor pans

I think TIG is less likely to burn-thru. It is more delicate, like soldering on steroids (use both hands). I read the Chinese TIG/Plasma setups work well and are compact, but still pricey (~$350). The biggest problem w/ the baseline HF flux-wire welder is that it only has 2 power settings (min/max, plus wire-feed speed). On min, I have butt-welded exhaust pipes and 1.25" EMT tubing w/ no burn-thrus, but even a little gap gets burn-thru started, and hard to not have some gaps if trying to patch a large section. The trick is to hit it with little "spot weld" bursts, instead of trying to run a continuous bead. Use a drill wire-brush between each re-start. That also gives less warping. The gas flux-wire welders give less spitting. The HF welder has paid for itself many times by doing frame repairs and such. I saw bluing on the opposite side of 3/8" steel when welding tow brackets, so gives good penetration on "max", all from $90 and a 120 VAC outlet.