Millermatic 200

I got the .023" drive rolls on Friday. This weekend I experimented on sheet metal for the first time. I was welding 22 gauge and I can weld it but it's pretty easy to burn through if not carefull. I have the voltage set one notch above the lowest setting. I really can't get it to weld on the lowest setting. On number 2, it welds nice but I have to keep moving or it will burn through. I think it will be quite a bit easier on 20 gauge which is what these cars are.