well i have started to rip my car apart to replace the floors, i bought a cut off grinder and although my air compressor is a bit small, it seems to work pretty good, i will admit i bought a spot weld drill as well, i had my doubts about it, but i am very impressed by the way it works. i will probably pick up a couple of more of them just to be on the safe side. I read on here to use a small drill bit and drill all the way through the spot weld first, and i admit that is the best way to do it. I guess the point of this thread is to say thanks to everybody who recommended the right tools for the job, this will make it quite a bit easier.

 

I never drill 1st, I punch mark and use a spot weld drill that is a small hole saw like cutter on a spring loaded bit with a pointy guide pin spring loaded, align the pin press down with the drill spinning and you can "feel" it going through the upper layer of material. A small air chisel and same hammering then usually makes short work. Next with a small 90deg. angle grinder I grind off the residual spot welded upper layer for fresh metal.

This thing!

 

I use a 1/2 drill bit....works great.

 

thats what i have. i tried the center punch, but it still wanted to wander when starting the cutter. as for using a 90 degree grinder, i will only have to do that in a few spots, i am replacing the whole side of the floor with new aftermarket, so no grinding needed there.

 

Forget that, those cutters suck.

Cutter use "Winzer 993.02008132"
That is a 8mm, they have a 10mm if the spot welds are bigger, 8mm is most common.

http://www.winzerusa.com/?__event=br...4fab7c2a000965

For cutoff wheels try "Mirka 1226" (1/32)

http://www.abglovesandabrasives.com/...dsh-Off/Detail

 

I use the same style cutter as Twin Turbo and they work great.