Originally Posted by thegnu
lap joints are a good trick , heres another 1 you can try if butt welding to light gauge metal an I can get behind it I will clamp a peice of 1/4 inch thick copper plate behind the weld you can weld all day on that copper an it will never stick or burn through.
If I need to fill small holes I've used a penny clamped to the metal behind the hole then rosetta weld. When you're done the penny will come off and leave a welded shut hole in its place. Good when doing auto body stuff and filling screw holes where chrome or parts were attached to the body.
Magnets are also useful for holding small, hard to clamp parts in place until you get them tacked together.