hey guys,
thought i'd chime in on this as well. I recently put a quarter panel patch panel on a '66 Impala. I'd previously read an article about using a certain technique to butt weld the panel so i gave it a try (may be typical, but the first i'd heard of it). basically i put the new, replacement panel over the top of the panel needing replacement (due to rust). I used self tapping sheet metal screws to hold it in place. Then i used a air cut off wheel w/ a .035 thick wheel. Then i carefully cut around the edge of the new panel all the way through the old panel underneath. Once completed, it leaves a .035 gap between the new panel and the remaining sheet metal around the outside...which was perfect for a butt weld. I believe the article was in "Classic Trucks" magazine and he actually did this technique on floor pans....which is overkill in my mind. But, worked very well for me on the quarter panel, got it welded in, ground down, and it turned out great.
