[john walker's workshop]

spot weld only. no continuous beads. sheetmetal welding with a mig is just a series of overlapped spot welds. first, position the piece in place with a spot every inch or so, then do a series of spots for about 1/2 inch from each original spot, moving around from one area to an opposite area to keep the heat down. don't cool it with a wet rag, because that can cause more warping than the original weld. let it cool by itself, then weld more. a bright light behind the panel will show pinholes which can be spotted closed.