Thin metal welding tricks

Go to the hardware store and buy a $ .49 copper sleeve for 1/2" pipe and smash it flat in a vise or with a bfh. Hold it behind your weld and you will be good to go. Setup is everything, you should be able to weld real thin with .023, most of the sheet metal I have done is with .030. Don't try to run beads just a series of tack welds is all you are after. Stitch the panel in every inch or so and let areas cool, go back and stitch in between your previous stitches until you are done. Then grind her smooth