Originally Posted by
Jessica de Boer
Stanley Covington recently told me about an experiment that was done at a university in Japan on a convex vs a flat bevel. They found it's faster to sharpen a flat bevel and there was no noticeable difference in edge retention. The bevels on my chisels have always been convex so I decided to see if I can get them completely flat or at least very close to flat. I found it impossible to create a truly flat bevel by freehand sharpening them but I'm very close. My bevels still have a tiny bit of convexity, maybe 0.25mm but I have already noticed a difference in speed of sharpening. It's now much easier to erase the scratch marks of the previous stone as I work my way up in grit size. I have ordered a Richard Kell Nr.2 honing guide and my plan is now to do the initial sharpening with the guide on the coarse grits to create a flat bevel (and keep it flat), and do the finer grits freehand. I'm also going to make a block with several stops so I can easily set the distance I need for my oire, usu and atsu nomis.
Jessica, how did you measure the .25mm or even detect it?
Chris
Everything I like is either illegal, immoral or fattening