Im a welder for a living. I have used from -023 to 5/64 wire. What I use at home is .030 its the best for the smaller welders. I use straight c02 gas. It gets alittle more penitration then 75/25 and it lasts a lot longer the bead may not be quite as pretty but it gets the job done. Yes it will weld thin sheet metal too. A good trick for sheet metal is to get a copper bar and hold it up to the weld joint to take away some of the heat so you dont burn through. And trigger or spot in the weld if you have too. make many many small welds so you dont warp the metal. I have built some trailer hitch drop stringers with my setup. Also On think stuff get a torch and preheat it. That will help ALOT. I did a vertical up weld test on 3/8s and passed with mine.
