Miniature belt sander

[crashtech]

Been reading this and just thought share some thoughts. I've probably had to remove as many or more spot welds in the last 32 years as anyone on the forum. The only place a belt sander would be better than a die grinder with a weld grinding wheel would be in the odd inaccessible place. In those spots I use a drill bit or a spot weld bit. But those spots are few and far between as a spot welder has to have room to do its job. Nothing is going to cut a spot weld quicker or more economically than a weld grinding wheel on die grinder. Anyone who says different has no idea what they are talking about. Belt sanders are harder to control, slower and less economical.

My favorite size is the one on the blue die grinder. 1/8" inch works well too and is cheaper.

I have watched my helper in action with both cutoff wheels and belt sander, and he is ridiculously fast with the belt sander. it could be that our sander and belts are different that what you have, though. One other nice thing about the belt sander is that it's easier to direct sparks in the direction you want, where with a wheel it's often more limited just due to the geometry of the wheel and tool. I personally prefer cutoff wheels because it's what I am comfortable with, but in the right hands, our 1/2" wide 3M belts just rip through the welds.

 

[Evil_Fiz]

I bought the WEN 1/2" belt sander (Amazon Link: WEN 6307 Variable Speed Detailing File Sander) recommended earlier in this thread. I can't speak to its longevity but the build quality appears good, and it performs as well or better than expected. Combined with 36 grit 3M Cubitron II belts (PN: 33443) it made short work of grinding the back-side of some welds I couldn't otherwise get to.

Thanks for the recommendations,
Emil

 

[theastronaut]

I bought a 3/8" CP 858 last year and it's been handy for getting into tight areas where nothing else would fit. I most recently used it to knock down the welds on the back side of a cowl panel. I had shaved the antenna hole and had a low spot from weld shrinkage, but there was no access to the back side for planishing. I ended up having to cut out the lower edge of the cowl to fix rust so now I had access for planishing, but the weld beads needed to be smoothed first. The belt sander was just right to clear the inner door jamb bracing and reach the weld beads.

 

[Dean Jenkins]

I simply find the spot weld and grind it. You use the edge, just like you would use a thinner cut-off wheel. I use the same tool to grind welds as well.

So find your spot weld and then use the wheel, grind until you start seeing the metal turn blue. When it does that you know that the top panel is getting very thin in that spot. Do the same procedure for a few more spot welds.
Then I take a thin chisel, actually an old KD-Tools gasket scraper and put it between the panels at the spot weld I want to break. Start gently hammering the chisel manipulating it until the spot weld separates. Sometimes you may need to go back and grind a little more. Better to be conservative in order to not dig into the bottom panel.
Any thin gasket scraper works well for this. Keep the angle edge facing away from the panel you are removing.

I think @Chris_Hamilton has it right. I was using the spot weld cutter bits, but you basically have to drill a hole through the spot weld for the pin, or it will slip all over. And good chance of cutting into the panel that will be re-used.

I just pulled two door skins off and used Chris's grinder method. I'm sold!