In my last post, I showed the three chisels I bought from an antique store to restore. Now I’m going to show how I cleaned them up. I put them in the electrolysis tub to derust them and then oiled them to keep the rust from returning. I made sure not to clean and oil the insides of the sockets for a reason I’ll explain below. In the picture below, the top chisel is a firmer, followed by two paring chisels which are ground for paring work.
Two of the chisels had handles already. One of the handles was worth reusing while the other had a large crack in it. I decided to clean up the good handle by stripping off the finish using the lathe. I put it on the lathe and sanded back to bare wood. Here’s the handle before I started.
Once I was happy with it, I put a coat of boiled linseed oil on it. The end of it was a little beat up so I touched it up using the belt sander.
The firmer chisel had the cracked handle that I didn’t want to reuse. To make a new handle I found a piece of wood that had been drying since October. I don’t recall what kind of wood it is but it was very tough. I cut out a block of it and roughed it into a cylinder.
These types of chisels are called socket chisels due to how the handles fit into the chisel. The inside of the socket is tapered which means, if you want your handle to stay attached, that your handle must have a matching taper. To do this, I get the cone on the handle close to the right size and then use a trial and error approach to fit it. I take the handle on and off the lathe and try fitting it in the socket. With the handle in the socket, twist the handle. This will leave a mark on the handle showing where it is contacting. If the inside of the socket is still a little rusty it will leave marks for you. If not you will need to find something that will show the contact area such as soot from a candle or a marker. If it marks up the cone uniformly along the length then you’re done. If not, go back to the lathe and remove a little material where the marks are. Repeat until the marking pattern covers all of the cone. Here’ a pic showing a test fitting and the resulting marks.
Here’s the handle after I finished sanding it.
I made another handle for the wide paring chisel using the same technique described above. Next, comes sharpening. First, I ground the edges of the chisels perpendicular to the sides using the grinder.
Next, I freehand ground the bevel on the grinder being sure not to burn the edge which will make the metal soft. If you look close at the top left corner of this chisel, you’ll see a small bluish area where I got it to hot. This has to be ground off to get a good edge.
Here are the edges off of the grinder. The wider paring chisel had a decent bevel on it that didn’t require the grinder. These bevels are used only to clean up the surface. The cutting edge will be created using stones.
To make a sharp edge you need to surfaces that intersect along a line. I first start by flattening the back near the edge. I used some 150 and 220 grit wet-dry sandpaper on my granite block because they removes metal faster than my sharpening stones.
After that, I used 800, 4000, and 6000 grit water stones to polish the backs. They aren’t perfect I think they’re good enough.
With the backs flat and smooth I turned my attention to the front of the chisels. Once again, I roughed out the bevel on the sand paper and then turned to the sharpening stones.
After this you can strop the edges if you feel the need to. Here are the restored chisels. I really wish I remembered what kind of wood I used for the larger handle. The thinner, middle handle is red oak from a dowel I had in the scrap bin. All in all, not bad for $9 and a bit of time.