Mig welding using short circuit transfer can handle sheet metal thickness all the way up to the beefy thick metal if done right. But for the really thick stuff, spray transfer can be the ticket. 90/10 argon/co2 gas allows for spray transfer if you are using .035″ er70s6 wire at about 25 volts and 350 ipm inches per minute of wire feed speed. It’s hot… It’s fast… and it really needs a heavy duty mig welding machine. read more