Brace yourself! A brand new review is coming up online...

Yes Chris the question is do you do that on debas? What would be the reason for that on a single bevel? This here is a simple overgrind. You can see how both edge and shinogi lines are lifted.

I would agree that a tad higher heel on a chefs knife could make it more pleasant sometimes, for the rockers at least.

So I had a bit of time to just continue with the XC.

Flatened the bevel so its ready now to attack it with C


Now on this photo you see a light reflection of a .5mm at the edge. This is desirable imho, cause now I will grind on the back side as well as bring the front and back together, so this knife will have an edge finally.

The heel, on which I struggled a little


And I broke of little more of the tip


Which is no reason for panic. It actually just made the blade more interesting in a sense. Clearly the back side doesnt support the tip yet, but is it possible for this blade to be that hard?
The working with it is easy and pleasant. Used 12 minutes on the XC to make that bevel straight. Not bad at all.

 

UP!

This blade must have the worst back side I ever seen on any higher end single beveled knife.
Plenty of effort to make it just decent enough really. Waves all over the place, tip a drama.

Pictures to follow

 

Ahh, I understand. I've never used, or even seen a single bevel or deba first hand. I'm very much enjoying this thread .

 

OK so I started to grind the back



Here you can see how much of an gap there is for the spine to actually meet the edge

But Im closing the gap


Some wire edge?

 

Interested. Keep the updates coming!

 

Can you please elaborate more about problems with back side? I had no personal experience with single bevel knives and to me it's not obvious from your pictures what was wrong with back side.

 

I'm guessing that it's supposed to have a shallow hollow filling almost the entire back side, surrounded by a 3-5mm flat all the way around the profile of the knife. In the first picture, you can see that the hollow actually breaks through the edge bevel (which, remember...is supposed to go all the way around the profile if I'm correct) along the top nose area. In a practical sense, I don't know what issues this would cause...but I can definitely see it as sloppy work.

If I recall, it's called uraoshi?

Here is an image to illustrate:


I've been really considering doing some single bevel stuff, so this thread is of great interest to me.

 

Hm, please correct me if I'm wrong: the whole purpose of hollow ground on single bevel knives — is to ease sharpening (and maybe to make knife a bit lighter). From this point of view it seems that "before" blade would be easier (faster) to sharpen, because it needs much less material to remove. Apparently I'm missing something, but I can't understand what.

 

Possibly it also ensures that the blade is being sharpened evenly? If it's uneven to start, you could easily be changing the angle of the bevel on the off side.

Again, from a practical standpoint...like you, I don't know what the issue is in this...other than sloppy workmanship. We'll both just have to wait and see .

 

Jon at JKI can do a much better job of explaining this than I, but here is my take. The flat side of most Japanese single bevel knives is not actually flat, but concave. This helps with drag and release through food. The concave shape is called Urasuki. Sharpening single bevel knives, as you would expect, focuses a lot on the bevel side. A good knife has a complex bevel from the Shinogi line to the edge....often called a Hamaguri edge. You work your way down from the Shinogi line to the edge, usually in multiple steps, particularly if you want to add a micro-bevel. As you create a burr at the edge, both to remove the burr and strengthen the edge, you perform uraoshi sharpening on the flat side. This makes the edge less brittle. Master Sugai from Korin told me this isn't even considered sharpening...just burr removal. Too much and you're wasting your your edge.

 

This makes total sense...and as I mentioned, that flat ridge around the entire concaved urasuki would be sort of a guide for ensuring you're keeping the entire 'flat' side of the knife in proper orientation on the stone.

 

OK so I got a small hour to work on this thing. I will explain in a little more detail









Here is the most clear picture I managed with the back closest to how it looks in reality.

Anton, to answer you, the lower arrow is pointing into the the place the twist itself starts. How is that? [It is most annoing and visible on usubas] At this exact spot youre grinding most metal away[from the bevel side, when sharpening and/or thinning the bevel].
Think of it this way: spine is straight more or less, but the edge side, on the other hand, at the mentioned spot, bends inwards, towards the heel. This makes for this spot to be the highest point and naturally your removing most metal right there.
So with a flat edged knife like usuba, this will mean the hole will just keep on getting more shallow and eventually you end up with a blade that only touches the board with the heel and the tip.
The other story is the heel, there is the same story just on a smaller scale. This is why the The end of the heel lifts up.
ANy of this makes sense? I am tired today cant even read it myself

 

Man, they really chunked up that grind, didn't they.

 

Looking forward to see how this one comes out.

 

UP!
It came out. I cant really do any more with it Bill. I find it a shame for someone reputable to sell this for premium coins. This is cheapo Yoshihiro , in fact NO!, my cheapo Yoshihiro seems to have gotten better QC than this...

I was able to break down one halibut, not really impressed with the edge, but at least managed not to break the tip...Have to sharpen it one more time, and off it goes to the owner next week.

 

When you say that the blade "twists" are you describing an issue with the grind (overgrind)? Or is it warping after forging and heat treat that wasn't straightened?

 

The blade is bent. Or edge side of the blade is bent.
I dont know really if its warped after forging or its just badly finished... My guess forging but HEY, it was made by the best smith out there. According to best mastersmith bodybuilder