I have been practicing butt welding before trying a patch on my truck. I am using a millermatic 185 with .023 wire and gas. I have been stagering spot welds and trying to hammer and dolly the spots to counteract the minimal warping/shrinking that is occuring. This has worked well. The problem is that the area of the patch is partially obstructed by an interior metal panel that will prevent me from doing any hammer and dolly work. Am I missing something? Is there another way to butt weld and avoid the shrinking? I have actually tried this on a scrap bed panel and the end result is horrible.