sharpening chisels and block planes

Sharpening Jig on Bench Grinder for Chisel and Planes

I made a wooden jig to hold the blade at a correct angle so I could use my bench grinder to sharpen chisels and planes.

After testing I found it works very well and can sharpen a blade very quickly. The main danger is overheating the metal and damaging the temper.

Design Parameters

This sharpening jig holds a chisel or plane blade securely, can slide accurately across the bench grinder wheel, and can be adjusted for many angles from 90 degrees to 20 or so degrees. This looks after just about any situation I could think of.

Bench Grinder Jig

sharpening Guide

This is what I came up with. I use 2 hands to hold the sliding holder but one hand is holding the camera.

I have inherited some really badly mistreated chisels and using one as a test. It was badly corroded and nicked. I've ground the back flat and the end that is near the edge is very clean and now will grind the nick out before actually grinding the angle. I guess I could do it all on the wheel but it would take forever.

sharpening jig

This is what it looks like without the little holder. There is a slot that runs across.

The jig is bolted to the workbench but I cut a slot in the base so I can adjust it and move it forward or back. I made the slot by making a series of holes and using a file to smooth it out. My router is still packed somewhere? I will never move again.

I had a maple board so that's what I used. I think it needs to be a hard wood which will not flex.

sharpening with stone

Detail of the holder. It can hold a plane blade, or by using the middle hole as in the photo, a chisel can be clamped in. I only had one butterfly nut, I'll get another.

The bottom section of the holder fits exactly into the slot in the jig. It is also the same thickness as the slot, or rather a breath thicker. The top section is slightly thicker. It slides easily. I'm planning to put a thin coat of shellac over the jig to keep it clean.

sharpening with stone

The underside view shows the recessed hole that fits the end of the bolt. I did not seem to need to glue it in place but if it starts not tightening well I will put a bit of epoxy in the space and shape the hole so the bolt does not spin when the top nut is tightened. I think If I oiled the bolt and bedded it into the hole with thickened epoxy I could remove the bolt when everything had set and have a nice hex shaped depression.

grinder sharpening jig

The pivoting piece is made of 2 thicknesses of maple. I cut a 45 degree angle so the jig could be closer to the wheel. It pivots on a threaded bar. Before I glued the 2 pieces together I made a slot that fit the treaded bar tightly. There is no wobble in the pivot. I could not figure out how to make a hole through so I used the table saw and cut shallow grooves in both pieces to fit the rod. I used a file to round the hole. It worked well and when I glued the 2 pieces together I put the rod in so it would be perfectly aligned. I slid it out after, to cut it to length. It's a quarter inch rod and I had a butterfly nut to fit it. There is enough clearance between the piece and the support to put a washer on each side. It tightens well and holds its position in use.

The support sides of the jig have curved ends. This allows the little sliding holder to slide over the side.

sharpening with stone

To keep track of the position I used the same method I have for the honing guide. I'm showing the honing guide here but I also brought the wooden holder to the edge and traced the chisel. In fact I glued a small piece of wood at the end so I can just push the chisel in the exact spot again.

How did it work?

After trimming the threaded rod and placing the chisel in position I checked that everything was square and that the angle was good and slowly started grinding.

The jig worked very well and slid smoothly across the wheel. I had dressed the wheel so it was nice and square.

The main problem of this set up is that the blade heats up quickly and it's very easy to overheat it. I'm using a carbide fine blade but it is not designed for fine sharpening. There are nice wheels made for this and I think it would be a good investment. Lee Valley has one for about 45 Canadian.

I think the way to use this set up is to make several little sliding holders and mount several chisels that need sharpening. Then slide one across, let it cool, grab another slide it across, and have 3-4 going at once.

It worked very well in my test chisel and I think I will add this to my regular sharpening.

NOTE: After some time and much use, I have found that the jig works really well for a quick and easy sharpening of chisels. I've tried it on the planes and I found that once again it is useful. It has not given me as good an edge as careful hand sharpening. This however takes more skill. What I am doing now is keeping a couple of planes for hand sharpening and a couple for quick use and I sharpen these on the grinder. I got a better wheel and it does not heat up as much so I'm pleased with it.

email me if you find mistakes, I'll fix them and we'll all benefit: Christine