Mortise/pigsticker chisel sharpening question

[Evan Ryan]

I want to sharpen this old chisel that I bought to cut big mortises.

When I see big mortise chisels they usually have a curve from the shaft to the tip, but in the sharpening advice that I've found, people sharpen pigstickers and they get rid of that curve.

Do I sharpen it like the drawing that I've included, the bevel is a long straight angle? Like Ray Iles mortise chisels.

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Or can I just sharpen the tip after the curve, like the photo I've included with the chisel laying on my grinder rest?

Most of the threads I have seen are concerned with secondary bevels, and I bet my question is basic, so
thank you for looking and providing your help and any opinions you have about getting this chisel working.

[Kees Heiden]

Some people indeed recommend a curved bevel. It should engance the leverage inside the mortise? I wouldn't think too much about and just sharpen the edge.

[Warren Mickley]

Evan, I recommend a flat bevel at 30 degrees or slightly higher. In use a mortise chisel rides on the bevel, so a flat bevel makes it more stable and so easier to control. The heel is helpful when levering out the waste especially in deep mortises; it acts as a fulcrum.

[Brian Holcombe]

Evan, I recommend a flat bevel at 30 degrees or slightly higher. In use a mortise chisel rides on the bevel, so a flat bevel makes it more stable and so easier to control. The heel is helpful when levering out the waste especially in deep mortises; it acts as a fulcrum.

Warren's advice has worked wonderfully for me. I used to despise hand mortising, then I saw his suggested method in a thread a while back and put it to use. It's spot on and now I can move through a mortise pretty quickly and with a clean cut.

[Evan Ryan]

Thank you for the help.

i should've mentioned that it is a 7/16" mortise chisel.

so historically, and I'm asking out of pure curiosity, I am not a period furniture maker, was the curve an old sharpening method?

[Patrick Harper]

I'll echo what others have said. I'll add that I really like a shallow primary bevel and I try to keep the secondary small (20 and 35 degrees or so, respectively). The small primary bevel allows the chisel to drive deeper with a given amount of effort. Ray Iles espouses this setup for his mortise chisels.