At the end of January, I joined several members of the St. Petersburg Woodcrafters guild at Heritage Village, where we demonstrated some traditional woodworking techniques.
One of the things we were trying was cutting some three-sided tenons (basically, deep notches) using hand tools. Andy Gibson, the guy who put a new handle on my rip saw, was slicing and dicing with the best of them as he cut the two sides of the notch. But, to slice out the bottom of them, he was using a mortising chisel I had purchased a few years ago. Andy whacked the heck out of it as he cut into the wood, and remarked, “Dude, why don’t you sharpen your tools?”
Which got me wondering – have I ever sharpened my mortising chisels? The answer is a resounding no.
So, my first thought was to turn to my Tormek with the standard straight-edge guide – the regular method for sharpening bench chisels. But, there is a slight problem…
You see, mortising chisels are so much thicker than bench chisels. They are designed to be banged on with a mallet, driven into the cut. So, they have to be much tougher to take that beating. Which means, of course, they don’t fit in to the square edge jig.
Bummer.
So, I started reading through the guide for my Tormek, and I thought it would be a good idea to use the universal platform for this. It is basically a piece you can adjust to any angles and clamp on the guide bar.
And, this worked OK. It was difficult to keep total control over the chisel, and I spent a lot of time concentrating on holding the bevel against the wheel and holding the chisel as straight as possible.
The results were OK, but not spectacular. My bevel ended up faceted, and I was afraid that my grip could have shifted during the session, leaving me with a non-square tip.
I will have to do some more research on this, but I’m sure that as versatile as this tool is, there is going to be a solution…
Hi Tom,
Here are two options:
1. There’s a Tormek jig that can be used for parting tools (as well as skew chisels, roughing gouges, and others). It’s the SVS-50. I’ve mounted a mortise chisel in that jig the same way that I would mount a parting tool, and it works really well for that.
2. Most mortise chisels have a pretty high bevel angle, about 35º or so. You can use the Tormek (or a regular grinder, which would be way better) to roughly grind a bevel at 30º, and then freehand a 35º microbevel on the universal platform. Since the area of contact of the microbevel will be very small, it will be a lot easier to control the chisel as you freehand it, compared to having the whole bevel contact the Tormek wheel.
I don’t own and don’t use mortise chisels, but maybe instead of hollow grinding on the Tormek, you just hone/sharpen on stones.
Tom,
Could you not simply use a small square against the rear edge of the Universal Platform to ensure you hold the chisel at a consistent angle? Then again, facets on the bevel aren’t really a problem, anyways.
Chris
Another vote for some type of stone sharpening. A cheapo side clamp honing guide and a set of stones would make quick work of your mortising chisels.