concave cut?

[pbadad]

Ball rasp or spade is correct. I will help you w/ the spade modification if you need it.

[numbskull]

I've done the ball rasp thing and that is not pleasant. In prior posts guys have talked about a carbide spiked rasp (looks sorta like a dandelion) ......a "cutzall" maybe (?) that supposedly will do it without burning or catching.

First time I read about it I asked Flap to cut mine, since he was the closest Klutzall I could think of, be he just got mad and told me to go search again.

[Mr. Sandman]

I asked this question a month or so ago and picked up one of those ball rasps. Well, it drew blood the first time I tried it but I think I got the technique now. You have to hold this in you hands while you work it in your drill press. Don't push too hard, it will run off the side and CUDZULL your friggin hand up in a nanosecond.
If your skin touches this thing, it will start taking lots of small chunks out of it in a hurry. Be careful, it is agressive. That said, it does a nice job on the wood, once you clean the blood off. I need to get a larger set of balls now. (both meanings)

[outnumbered]

Saves you from coloring the mouth red though.