regrinding chisels for dedicated paring

[Duncan S Robertson]

I have a set of 9 chisels from 1/8" to 3/4" that I want to regrind for dedicated paring. I do a lot of work in pine and the softer hardwoods. I've been told to grind them to a 17 degree angle. Why 17 degrees? If 17 is good would 16 be better or would 20 be as far as you want to go? Suggestions on the best way to change the bevel angle? Thanks for the help
cheers,
Duncan

[Frank D.]

Hi Duncan,
For paring 20° is fine; less might give you an edge that's too fragile so you'll spend more time touching it up than paring, and your bevel will be quite long so it might bend easily and tend to dive into the wood. But if you put a microbevel on your edges, you won't be too far from 20° anyway. I'd say try out an angle (any angle) and see how it goes for you. If you're happy with it, fine; if not, change it.
I know I'd use a power grinder to change the bevel to a lower angle. Set up the tool rest to the proper angle and take your time, dunking in water frequently. When the water on the bevel starts to steam off, dunk for a few seconds. When you get close to the edge, you can switch to a coarse stone and continue by hand to make the bevel flat. If you want to keep a hollow grind, make sure the angle you want is at the very tip of the chisel. If you go for an average angle of 20° across the whole bevel (the angle between the heel and the tip of the bevel), the tip will be much too fragile with a hollow grind.
HTH

[Jim in Burlington]

Some chisels of better quality can stand to have a lower angle. Wider chisels can withstand lower grind angles in the under 20 degree's. Personally to change the bevel angles I'd use a magic marker and 6" grinder. Smaller chisels can be done by hand easily with sandpaper and glass setup.