I have mentioned in previous posts that my preferred method of sharpening for chisels and plane irons is on my Eze-Lap diamond plates using a honing guide. I have also acknowledged that I ought really to try and ditch the guide and learn to do it freehand. Well, recently, I have experimented with some freehand sharpening with plane irons, with surprisingly good results. However, I have found that instead of a nice flat bevel, I end up with a rounded one; a convex camber if you will, that curves back from the cutting edge. I have learned from my maestro, Paul Sellers, that far from being a problem, this camber actually strengthens the cutting edge, supporting it and lengthening the time between sharpenings. I don’t know if this is true or not, but it certainly doesn’t seem to have a negative effect.
Anyway, the reason I am writing this post is because I doubt that a freehand approach will be suitable for my mortise chisels, and I don’t think that they will fit into my honing guide. So my question to you is: How do you sharpen your mortise chisels? Also, what angle do you sharpen them at? I have measured the bevel on mine and it is 25º, which is apparently fairly standard, but I have read that a secondary bevel of 35º is advisable. I am at a loss at how to achieve this with the equipment presently available to me.
If anyone out there can shed any light on this I would be most grateful. I have searched online for an answer, to no avail. Perhaps my googling skills aren’t up to it, so if anyone could point me towards some kind of tutorial, that would be fantastic. Any advice would be welcome.
Thanks everyone. Hopefully I’ll see you in the comments.