Reply to "Spot weld cutter???"

Larry, I have two kinds and have used them. Both work. Depends on how much access you have, and whether you intend to reattach a part again later. Type 1 is simply an odd-looking 'drill-bit' that really needs a clamp system (think portable drill-press with a magnetic base) to keep the reverse-ground 'drill' from wandering. It often goes thru both sheets of thin steel if you push too hard, same as a std drill bit. They are usually high-speed steel & need lots of cutting oil or they dull rapidly. I always have trouble with these things.

Type 2 is a tiny hole-saw (some are carbide; long-lasting but brittle)) that removes a little disc from the top sheet without penetrating the second (much). Needs the same kind of lube & clamp/guide system or it will wander, and it leaves a large-ish hole. Some of both types use pilots for hand drilling but pilots won't correct for drilling angled or off-center with any hand-held cutter. The little saw will absolutely remove all of a spot weld; reattaching the same part later means rosebud-welding each big hole you cut, to fill in the removed disc (only if you intend to reuse the part). The result will not look stock without a LOT of work on each hole.

I've also used a thin chisel & hammer between 2 sheets to tear spot welds apart without any drilling, but this also often wrecks any re-use of the removed part. Simple, cheap, needs very little access and you can even use a small air-chisel. You'll find that some spot welds are very firm while others are almost not there. Those are easiest done with a chisel & hammer. Save the spot-weld cutters for the really difficult ones.