Used Yanagi sharpening advice

[Heckel7302]

I bought this second hand Masamoto Yanagiba, my first single bevel aside from a couple of Kiridashi. It was used in a pro kitchen, apparently sharpened 6-8 times on a 600 synthetic Aoto and JNS 6000. I colored in the bevels and ran it on my king 800 to see what I was dealing with, using strokes with the knife diagonal to the stone. It appears that the previous owner sharpened it with lateral strokes, heel to tip. I surmise this not only from the lateral scratch pattern, but also the wear on the horn ferrule.

I appears to me that when it was sharpened previously the tip was raised when sharpening the heel leading to an over grind there, and heel raised a bit too much leading to a bit of an over grind at the tip. Or maybe it came that way. Who knows and it doesn’t really matter how it happened.

What would some of the more experienced single bevel sharpeners do in this situation? It seems a waste of steel to grind down the whole bevel to meet the heel over grind. I am thinking of just leaving it and eventually it will get down to even over time being sharpened. The tip I’m thinking of taking down though. No one ever complains about having a tip too thin, right?

I’d appreciate any insight. Thanks. Here are some pics.

 

[user 37848]

If you're planning to use it and don't care about picture-perfect aesthetics, just sharpen it, test it and slice things. Repeat this until you're happy with how it slices/cuts, whatever.

FWIW, I've had a few Masamoto's in which the horn was shaped like that when I received it brand new.

 

[ethompson]

Those are also very common places to find over-grinds on new knives, even higher end ones. My advice would be to sharpen normally and see how it slices and if you want to clean up the finish to use finger-stones or stone mud to blend those areas in and let them come out naturally over time.

 

[M1k3]

Have you checked to make sure the knife is not bent or twisted?

 

[Blank Blades.]

+1 for what @M1k3 said.

If I were going to fix the profile. (Which I would because it would drive me crazy if I didn't, not saying its necessary). I would probably do it pretty similar to a double bevel.

First check for straightness, and twists. You can do that by eye, and also by rubbing the ura side on a very flat, hard stone. Someone people look at the marks left on the stone to see what's going on, or you could color in the back like you did with the bevel and see what isn't getting worn.

After fixing any twists. Then I would basically stand the knife up and grind the profile I want with a very coarse stone. Then sharpen the blade to get rid of the flat spots from reprofiling. Then you can just go about it like you are sharpening it normally.

Oh and make sure if you are looking like you are getting too close to the concave in the back while reprofiling. You lay it down and sharpen a bit more to avoid getting the (I can't remeber the name of it, the little lip that is around the ura) to thin, you do want it to have at least a little bit of thickness to add stability to the edge.

 

[Heckel7302]

If you're planning to use it and don't care about picture-perfect aesthetics, just sharpen it, test it and slice things. Repeat this until you're happy with how it slices/cuts, whatever.

FWIW, I've had a few Masamoto's in which the horn was shaped like that when I received it brand new.

I'll be using it, but not a pro, so not very often. I mostly bought it because I wanted one and to play around with my jnats. So getting a nice polish on it is the goal, but I can live with the back corner not being perfect. Interesting about the ferrule. I haven't seen that in any pictures from retailers, but I guess it's possible.

Those are also very common places to find over-grinds on new knives, even higher end ones. My advice would be to sharpen normally and see how it slices and if you want to clean up the finish to use finger-stones or stone mud to blend those areas in and let them come out naturally over time.

It's a KA, not the highest end from Masamoto, but on the upper range, apparently hand finished. I suppose it could have come new like that with the low spots at the heel and tip. The heel I can certainly live with. I'm glad that it didn't have any low spots along the bevel.

Have you checked to make sure the knife is not bent or twisted?

It lays dead flat. No bend or twist for sure.

 

[ethompson]

Decent chance those over-grinds were at least partially there from factory - thiugh it remains very possible they were exacerbated over time. It’s my understanding it’s exceedingly difficult to not over grind those area when working on a big wheel.

If you want to rework geometry, one thing that is important is to change your angle of attack from 45° to holding the blade as close to perpendicular to the king axis of the stone as possible. This allows you the most localized control of geometry available.

 

[Pisau]

Subscribing.

the name of it, the little lip that is around the ura

Uraoshi. It's the loose term to describe the "lip", but strictly speaking it's a technique of flattening/pushing the ura thus "ura-oshi" (from osu, push!) in order to achieve a really flat cutting plane bte which surrounds the uraski. Although, in reality I personally do it very lightly on kitayama. Anyway..

It lays dead flat. No bend or twist for sure.

I'm more concerned with the back, what's it look like mate?

 

[Heckel7302]

Subscribing.



Uraoshi. It's the loose term to describe the "lip", but strictly speaking it's a technique of flattening/pushing the ura thus "ura-oshi" (from osu, push!) in order to achieve a really flat cutting plane bte which surrounds the uraski. Although, in reality I personally do it very lightly on kitayama. Anyway..



I'm more concerned with the back, what's it look like mate?

I was referring to the back when I said it’s dead flat. Here’s a pic from when I got it. It’s since just been cleaned up with flitz. The uraoshi is maybe a little thin a few cm from the tip, but within acceptable parameters I think.

 

[Atso_J]

The ura looks ok. The worst thing after an ura that looks like post nuclear disaster is an axe instead of a proper koba. Your edge looks pretty nice but you might wanna bring the tip to match the rest. Just leave the heel as it is and catch up over time. You could mayhaps clean the heel a little with a fine stone if there are any rough edges just to make sure it won't start slowly degrading.

I've schooled myself by bringing back nearly dead forgotten cheap low end yanagibas and that right there looks like a proper knife compared to those You're all good.

 

[Heckel7302]

Thanks. I may indeed bring the tip to match the rest. And yeah, this knife retails for over $600 and I paid about a third of that, so no complaints.

 

[Se1ryu]

Shinogi line doesn't look straight at the heel, lower than the middle part to the tip. Maybe you need to raise the shinogi kine at the heel a little bit. From the look in the picture looks like the kireha is flat from heel to kisseki (tip). Normal Yanagiba have a curve from middle side to the tip. and maybe you can work on that.

Ura side look fine just need a little bit cleaning with rust eraser.

Maybe the previous owner Sharpen the knife flat to the stone from heel to tip

 

[Atso_J]

Shinogi line doesn't look straight at the heel

To me it looks straight all the way. The kireha runs a bit thinner towards the edge at the heel which is fairly common (regular find for me on debas and yanagibas).

 

[Se1ryu]

To me it looks straight all the way. The kireha runs a bit thinner towards the edge at the heel which is fairly common (regular find for me on debas and yanagibas).

Yes the tip is thinner but looks like doesn't have any curve. IDK it's hard to tell from the pictures. We can feel it when sharpening on a whetstone