Belt Grinder For Wood Chisel Sharpening?

Belt grinders are handy, but they don't make very good tool grinders. They run too fast and you can easily overheat an edge if you aren't very careful. I finally changed mine over to VFD drive and it usefulness went up by an order of magnitude.

Another problem with full speed edge grinding is that a standing wave tends to develop in the belt just ahead of the edge (assuming you are grinding with the tool edge leading) which tends to produce a slight rounding of the edge instead of a flat. This is not a problem if you finish hone the edge on a flat stone, but you need to be aware of the problem

The belt platen will eventually wear hollow causing a similar problem as above, so watch out for that. I licked that on mine by making a new platen with a carbide wear surface. The piece of carbide was expensive, but eliminated maintenance of the platen for a very long time.

Randy

I would only use the belt to remove a badly damaged edge from the chisel. And then only with a frequent dip into the water cup to keep the heat down on the edge. Afterwards use the 1/4 or half sheet wet sanding papers on glass with progressively finer grits. Once they are back to serviceable edges I would never let them near a high speed grinder.

My two cents

Jim Vrzal

Unisaw A100 wrote:

That's a point that seems to be missed by many people. It is not to be taken lightly, especially if rake or relief angle is critical. The rounding occurs right at the cutting edge, so if you're sharpening something like a lathe tool that has minimal rake, it can quickly turn into negative rake at the point of contact. Sharpening drill bits by that method often yields poor results, a drill that appears to be sharp, but fails to cut properly because the cutting edge is ever so slightly lower than the area directly past it. Assuming you address these issues, a belt sander is far superior to a wheel in metal removal and cool cutting. I still prefer to use a wheel, one that runs at proper speed, roughly 6,000 SFPM.

Harold

I tend to agree with Jim, but I don't bother with the sand paper. I will grind a chisel if badly nicked, Then I use a diamond hone followed by a fine stone. The final is to buff to a mirror finish. Using this technique I end up with a razor sharp edge.

If you have a badly damaged wood chisel/putty scraper /paint can opener you can get it shaped pretty quickly on a belt. Notice I said shaped and not sharpened. Use a new 80 grit zirc/aluminum oxide belt and get the general shape defined and then take it to a stone. The 1" belt grinders with a leather belt and some chromium oxide rouge make a nice strop to just barely put that micrbevel on an edge. FWIW the enco 30" belt grinders don't have enough clearance to run a leather belt.

I got an old rusty abused Stanley 1.5" wood chisel for .$50 Sunday. It looked like it had been used to chisel concrete. I had to set the bevel back 1/4":

1) Wire wheel off the rust. 2) Grind free hand the bevel back on a standard 6" bench grinder course wheel while frequently dipping in water to cool. 3) With a 1-2-3 block and miter pinched in the fingers on the table of a white wheel carbide grinder with the table set at 90 degrees to the end of the wheel, make the bevel flat. 4) Soak a fine water stone in water and polish the bevel