Sanding hundreds of small round-bottomed holes

[Porter Bassett]

I'm making a board game with a bunch of 0.5" shallow round-bottomed holes for marbles, like you'd find in a chinese checkers game.

I'm having a horrible time sanding inside those holes. I'm doing it with a thin strip of sandpaper and my fingertip. It takes forever, and it hurts.

I tried gluing some velcro to the end of a pencil eraser and sticking little pieces of velcro-backed sandpaper, sticking the pencil in a drill press, and sanding that way, but the velcro-velcro contact wasn't strong enough.

I can't just take a rigid dremel tool to it, because then I'll just be gouging out divots in the holes instead of sanding them.

Any ideas on a better way to do this?

[Warren Clemans]

How about rounding the end of a 1/2" dowel, apply a small disc of sandpaper with spray adhesive, and chucking the dowel in a drill? Small discs of sandpaper will clog quickly, but it might be better than doing it by hand.

[glenn bradley]

Dremel make syntho sanding bits in different sizes and grits

http://www.lowes.com/lowes/lkn?actio...11E&lpage=none

[Jude Tuliszewski]

There are also mini sanding drums for dremel size rotary tools. They have a 1/8" shank and are variuos dia. I think Harborfrieght has them as well.

[David Keller NC]

"Any ideas on a better way to do this?"

Yeah - don't sand them. I suppose this might not help because the holes are already done, but perhaps a better way to make them would've been with a router, a core-box bit, a collar, and a drilled template. Provided the core-box bit is sharp, no sanding should be necessary.

If there's no other way around having to sand them, consider buying some loose grit, and make a hardwood dowel out of a suitably hard wood, like hickory (or even a scrap of rosewood, if you have it). Chuck the dowel into your hand drill, spread the loose grit over the surface, and use a drafting brush to sweep the grit into the holes. Then just buzz away with the hand drill and dowel, and turn the board over when done to empty out the grit.

[Doug Shepard]

Why do you need to sand them? Is there burning in the bottom of the holes or is it just a sharp edge at the top of the hole you're trying to soften?

[Bruce Page]

Get some grey or maroon Scotch-Brite, cut it into ~1” square pads, a 3/8” dowel chucked in a drill. Place pad over hole, push down with dowel, squeeze trigger.
Might work...

Might need to add some grooves to the end of the dowel so it will grab the pad.

[Mark Smith, too]

http://www.mcmaster.com/

Go to catalog page 2617. They have what you seem to need.

[Ken Massingale]

Buy or make a sanding mop, simple but great. Klingspors has them.

[Jack Briggs]

Originally Posted by Mark Smith, too

http://www.mcmaster.com/

Go to catalog page 2617. They have what you seem to need.

This is your answer, here.



Cheers,

[Porter Bassett]

Originally Posted by David Keller NC

"Any ideas on a better way to do this?"

Yeah - don't sand them. I suppose this might not help because the holes are already done, but perhaps a better way to make them would've been with a router, a core-box bit, a collar, and a drilled template. Provided the core-box bit is sharp, no sanding should be necessary.

That's how I was going to do it originally, but then I found a drill bit specially designed for marble holes. Unfortunately, I get a fair amount of tearout in maple. Maybe I should have just stuck with the router bit.

[David Keller NC]

Originally Posted by Porter Bassett

That's how I was going to do it originally, but then I found a drill bit specially designed for marble holes. Unfortunately, I get a fair amount of tearout in maple. Maybe I should have just stuck with the router bit.

Robert - If you build any more of these, I'd suggest sharpening the bit. I've noticed that even high-end Forstner bits are not up to snuff out of the box. I almost always hone them with slips like I would a carving gouge. The difference in performance, both in terms of speed, reduction in burning, and reduction in tearout is dramatic. You might have similar issue with that custom bit.

Of the solutions proferred, a carbide sanding burr might be your best option. If you've a Dremel, you can get bits like those in the McMaster Carr catlogue in a huge variety of shapes and sizes.

[Lee Schierer]

Originally Posted by Mark Smith, too

http://www.mcmaster.com/

Go to catalog page 2617. They have what you seem to need.

I was going to suggest the same thing.

[Kelly Craig]

I have often used round bottom and ball type grinding stones like machinist's use. They come in all types of grits and can smooth, polish and grind. Consider picking up a cheap set to experiment with.