Chisel Rehabilitation -- Setting the "finished" edge angle.

[gwagner]

I have a chisel that someone ground from the back side, so I must remove about 3 mm of metal before I get back to the flat on the back of the blade. As I grind the metal the edge angle will change. So if I start at 30 degrees and grind it all off I'll be at a much sharper angle when done.

Is there a trick or technique for setting the "finished edge angle" from the start, so that once all the bad material has been ground away I'll be at the 30 degrees I need?

Edit: Sorry -- when I saw the category of "planer blade" I thought of my carpenter's plane, which is a chisel blade. (I'll ask the question in the chisel category if I can find one.)

[RickKrung]

Hand Tool Woodworking subforum...

I don't have an answer for you, but I caution regarding avoiding too much heat as it will destroy the temper necessary to hold and edge.  That would be particularly of concern with so much metal to remove, which would be much more effectively accomplished on a standard or slow speed bench grinder.  You'll be at it all day if you try it with a standard Tormek. 

Rick

[Ken S]

Gill,

Here is alink to the chisel sharpening online class. Starting at minute 49, Wolfgang demonstrates supporting your chisel beneath the universal support bar placed close to the grinding wheel. If you are using the SG-250 or the SB-250, I would use it freshly trued. The SB-250 or CD-250 coRse will do the job more quickly. With any luck, you will be done by lunch.      Psychologically, you might wantto divide this job into two or three sessions.
Good luck.

https://youtu.be/wMATay8ITE8

Ken