Anyone have a hollow grind form for sanding the grind area?

I was thinking [yup- there he goes again] about a form for sanding the hollow grind on blades.

Maybe a piece of pipe the same diameter as the wheel that could be covered with sandpaper and stuck in a vice. Then the knife could be run back and forth across the form to clean up the grind area.

Any ideas?

Dave

Dave,I don't do hollow grinds,but if I was making a sanding form for it,I would cut a piece wood and glue a strip of rubber or leather to it. Make the combination the same diameter as your wheel and you should be good to go.Dave

If you have a grinder and can do hollow grinds now, why not use the grinder as your form? Sometimes I will put a new belt on my grinder and run it around a few times to get it centered. Then turn it off and slide my blade in and out froom the side of the wheel. Works great and you don't need to make anything special.

If you do want to make something else, why not just glue several pieces of particle board together and cut it to the diameter you need? You could cut that in half and tape sandpaper to it, set it on your bench and sand away.

Geno has a thick piece of rubber (He calls it the finger) that he wraps sandpaper around and uses that. It really works quite well.

How do I know? Because Geno gave me the finger a long time ago.

Up here in the frosty frozen north we use hockey pucks that have been reprofiled to fit the curve of the grind. They work great but you gotta use the rubber kind.

Hocky pucks is a good idea. I wonder if they are available in Texas. Not much ice here in the winter.

If you are looking to get a hand finish,or just to help clean up any little flaws use the above mentioned ideas,but remember to put a small radius on the edge of whatever you use.This will help eliminate any chance of scratches in the form of swirls that will ruin a hand finished blade.

Also whatever you make can stand to be a bit oversized(tiny bit) because the dia. is different with different grits of belts.(coarse are larger than fine,as so forth)

If you can't find a hockey puck (sounds like they would work well),pick up a sanding block from an auto paint shop.Cut into blocks and grind to the required radius.Make sure you use the hard rubber kind.I've been using these for a long time and they work well.
Doug

I use some stuff that is sort of like 1 " thick micarta- it is layers of canvas, but in a rubber matrix rather than phenolic. I got it at a place I used to work, and I *think* it was designed for use as either a shock absorber or electric insulator for heavy machinery.

It bandsawed fairly easily into pieces with radii consistent with my contact wheels (I made an 8" and a 10" version), and I just wrap a 1" strip around the edge. I use it for all of my hand finishing.

For a 8 in wheel the old fashion sanding block that is sold at the hardware store the rubber kind with a slit in each end that you use to hold the sand paper to the block, the ones at my store have a 4 in radius on the back side, just slice a 1 in thick piece off and you have a sanding blocb Gib

Rubber is what I use.
Wood, felt, macarta, plexiglass, cork, many things can be used as a backing.
Make your own and find out what works best for you.

Here is something that works for me, though I hardly ever hollow grind. When ready to hand sand I toss a few craft sticks (popsicle sticks) in a bowl of water. After they have soaked for a while they become limber enough to bend. I cut my sandpaper about 3/4" x 4". Then just hold the paper on the stick with your index fingers and push down with your thumbs. The softened sticks will conform to any hollow grind no matter the radius. This also allows some movement at an angle to the previous rub.

I made one of these for 12" and 8" hollow grinds. Uses sandpaper strips. I used contact cement to bond rubber to wood.

Bill I am dying to see this but I don't have access to the album ????

Can anyone else view the pics?

Thanks,
Dave

Dave, I edited the pic. You can probably come up with a more ergonomic handle. I just made these and I think I'll shorten the handle.
Bill

Neccessity is the mother of invention. I take an old 5/8" piece of garden hose, split it up the side, epoxy it to a 1" dowel rod some 6" long. It makes a pretty good radi when the sheet sandpaper is rolled around it one time--I normally use a little 3m spray adhesive. Guess there are a number of ways to get to the same effect.--Dan