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So I've become "the knife guy" at work, sharpening for my coworkers and such. I've done my chef's Miyabi Artisan SG-2 8" gyuto a couple times; it seems that it's kind of thick behind the edge and the bevels are getting rather large in the sort of way that indicates that it would benefit from thinning. He has used this one for a couple years, sharpening mostly on Miyabi's Rollsharp I believe, and I've never seen a brand new one so I don't know exactly how much height has been ground away (although I just realized that I could take a caliper measurement and compare to the factory specs).
I can get the knife quite "technically" sharp on my stones, i.e. it will do the demonstrative tests such as shaving hair, shredding paper, and so on, but in terms of "functional" sharpness, i.e. performance vis-a-vis cutting food, it seems to require more effort than other knives that are equally sharp at the edge. Of course, I'm still not very experienced with J-knives, so I'm unable to quantify how far out of original spec the thickness behind the edge and the cutting performance are, and how far from optimal the original characteristics are.
This knife, which I've seen described as "blingy" on either this or another forum, has a tsuchime finish, a mirror polish on the upper and lower parts of the blade, a kasumi type band between the upper hammered shiny area and the shiny area immediately above the edge, and what appears to be an etched line where the cladding meets the core steel. It looks like this would be difficult to restore to original condition after any grinding on the face of the blade.
Unfortunately/fortunately, I am cursed/blessed with a powerful drive to optimize and refine and to ensure that I do things as correctly as possible in the best possible way. From what I've read about thinning and blade geometry, I see my options as the following:
-Continue to sharpen the edge bevels as they are. He gives me the knife to sharpen, I return it to him sharper. Pro: no risk of damaging or appearing to have damaged my boss's favorite tool. He seems pleased with my work on it so far. Con: I think it could cut better, and eventually it will cut noticeably worse.
-Thin it above the edge bevels and stop there. Pro: It will cut better, maybe even impressively so. Con: it will look, if not ugly per se, quite different from how it's "supposed" to. In its original form it is admittedly beautiful, although I prefer the simpler beauty of my Gengetsu, Hiromoto, or Sabatier.
-Thin it and restore the finish. Pro: better cutting performance, without diminishing the aesthetics. Doubly impressive. Con: I don't know how to do this. I'll have to figure out thinning first, which I'm working on with some cheap knives, intending to progress to my old 10" T-I Sab and maybe my MAC, and then polishing -- this thing is more reflective than any knife I've ever seen, so I wouldn't know what to use. 15k stone? 5000 grit automotive sandpaper? Polishing compound and a cloth? That's not even considering the four different finish types on this knife and the order in which to perform the operations.
So now that I've written this out, clearly in the short term option 1 is the safest - low risk and do exactly what Chef asks, option 2 is what I'd start with if it were my knife but is not viable for someone else's, and what I really want to do is option 3, despite the effort and learning required, because the term is knife knut and not knife knormal for a reason, amirite? :biggrin:
There's also option 1a: sharpen, do not thin, but ease the shoulders in a hamaguriba-esque sort of way for better cutting than an abrupt change in angle, if I understand the process accurately, and 3a: learn how to do all the tasks first, thin some knives, polish some metal and find a method to get it as shiny as a new Miyabi, and then offer to do it for other people.
What do you think? Any tips on thinning and restoring complicated finishes?
I can get the knife quite "technically" sharp on my stones, i.e. it will do the demonstrative tests such as shaving hair, shredding paper, and so on, but in terms of "functional" sharpness, i.e. performance vis-a-vis cutting food, it seems to require more effort than other knives that are equally sharp at the edge. Of course, I'm still not very experienced with J-knives, so I'm unable to quantify how far out of original spec the thickness behind the edge and the cutting performance are, and how far from optimal the original characteristics are.
This knife, which I've seen described as "blingy" on either this or another forum, has a tsuchime finish, a mirror polish on the upper and lower parts of the blade, a kasumi type band between the upper hammered shiny area and the shiny area immediately above the edge, and what appears to be an etched line where the cladding meets the core steel. It looks like this would be difficult to restore to original condition after any grinding on the face of the blade.
Unfortunately/fortunately, I am cursed/blessed with a powerful drive to optimize and refine and to ensure that I do things as correctly as possible in the best possible way. From what I've read about thinning and blade geometry, I see my options as the following:
-Continue to sharpen the edge bevels as they are. He gives me the knife to sharpen, I return it to him sharper. Pro: no risk of damaging or appearing to have damaged my boss's favorite tool. He seems pleased with my work on it so far. Con: I think it could cut better, and eventually it will cut noticeably worse.
-Thin it above the edge bevels and stop there. Pro: It will cut better, maybe even impressively so. Con: it will look, if not ugly per se, quite different from how it's "supposed" to. In its original form it is admittedly beautiful, although I prefer the simpler beauty of my Gengetsu, Hiromoto, or Sabatier.
-Thin it and restore the finish. Pro: better cutting performance, without diminishing the aesthetics. Doubly impressive. Con: I don't know how to do this. I'll have to figure out thinning first, which I'm working on with some cheap knives, intending to progress to my old 10" T-I Sab and maybe my MAC, and then polishing -- this thing is more reflective than any knife I've ever seen, so I wouldn't know what to use. 15k stone? 5000 grit automotive sandpaper? Polishing compound and a cloth? That's not even considering the four different finish types on this knife and the order in which to perform the operations.
So now that I've written this out, clearly in the short term option 1 is the safest - low risk and do exactly what Chef asks, option 2 is what I'd start with if it were my knife but is not viable for someone else's, and what I really want to do is option 3, despite the effort and learning required, because the term is knife knut and not knife knormal for a reason, amirite? :biggrin:
There's also option 1a: sharpen, do not thin, but ease the shoulders in a hamaguriba-esque sort of way for better cutting than an abrupt change in angle, if I understand the process accurately, and 3a: learn how to do all the tasks first, thin some knives, polish some metal and find a method to get it as shiny as a new Miyabi, and then offer to do it for other people.
What do you think? Any tips on thinning and restoring complicated finishes?