# single bevel sharpening



## noj (Mar 6, 2022)

I have a new-ish single bevel knife, and a question on sharpening.

The knife, as new, was ground so badly, I sent it off for professional help. They did a good job of fixing the major problem: the entire flat section had a significant frown. It may have had other issues, but it was hard to tell with the frown. The knife came back with the frown gone, and nice flat surfaces (no concave spots).

The knife cut ok, but felt like it wasn't thin behind the edge. I lived with it, until it needed sharpening.

The issue at hand is the bevel between the lamination line and edge. When I place pressure very near the edge, there is no obvious angle I can feel. If I continue to grind in that manner, it's taking what seems like forever to remove the old "micro-bevel" (it looked like a macro-bevel to me). In fact, I can't really get to the edge without rotating the blade, which of course would make matters worse.

When I look at that surface in the knife, I see increasing convexity as I (visually) approach the edge. The last 2 millimeters are highly curved. The lamination line is about 6-8 mm from the edge. I would have expected most of the convexity to be near the lamination line, where the bevels are smoothed together. I am writing to confirm my expectations, and to inquire how I can make the blade better. I am not going to make complaints against the professional sharpener.

I am not sure how to proceed. Is the hamaguri geometry I described expected, or should be preserved? It doesn't match my understanding.

I was thinking of using a coarser stone to grind the entire bevel flat to the edge.
Perhaps I can get roughly the right angle on the bevel from lamination line to edge by just adjusting pressure afterward.

Please comment on my idea, or suggest a better approach.

Thanks in advance!


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## M1k3 (Mar 6, 2022)

Any pictures?


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## noj (Mar 6, 2022)

M1k3 said:


> Any pictures?


Just uploaded


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## adam92 (Mar 6, 2022)

You will find the answer how to sharpen single bevel knife from Jon video. It is very useful.


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## noj (Mar 6, 2022)

In case it helps understanding where I am coming from, much of what I know about single bevel sharpening comes from Jon at JKI. But thanks for the tip. It doesn't help with my questions though. If you compare my questions to Jon's videos, it's the difference between the geometry of my knife, and what is in the videos that is at the heart of my problem.


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## Greasylake (Mar 6, 2022)

If you wanted to thin the knife, you would need to move the shinogi up by doing shinogi sharpening like Jon does in the video, but I think you might notice an improvement by just grinding down some of the convexity and essentially thinning just behind the edge. You'll need a coarse stone for that, or it'll take forever. If it were my knife I would probably put it on a coarse stone until I ground down that big edge bevel and put my own edge on it, then see how it cuts before moving the shinogi. You are right that the convexity should be where the bevels are blended, convexity towards the edge is usually from not keeping a consistent angle (ask me how I know )


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## noj (Mar 6, 2022)

Greasylake said:


> [snip]



Thanks for the reply. That gives me more confidence I am on the right track.

The whole blade geometry wasn't my doing. Not so far anyhow! 

Regardless of where the convexity (and dang macro-bevel) came from, it sure makes knife sharpening a chore. I spent an hour on a 1000 grit to reduce the "micro-bevel" thickness by half. Add to that no feedback on the angle (from lamination line to edge), and I wasn't having fun.

I'll carefully read any other feedback, but if not, will try your approach, if I understand it. I think the only way to remove the convexity near the edge is to first grind the wide bevel dead flat (from shinogi to edge). After that, re-grind a secondary (larger) angle from lamination line to edge. Can that be done by just applying finger pressure near the edge? Setting that bevel consistently by hand, just a few degrees higher, would be a challenge.


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## adam92 (Mar 6, 2022)

Hope to see your result soon.


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## noj (Mar 6, 2022)

Any stone recommendation for the course stone? The only one I have (under 400 grit) is quite soft. It works great for thinning convex double bevels. I am not sure I trust it for setting a flat surface.


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## Greasylake (Mar 6, 2022)

Shapton glass 500 is what I use


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## M1k3 (Mar 6, 2022)

Norton Crystolon Medium
Norton India Medium
King 300
Shapton Pro or Glass 120


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## ian (Mar 6, 2022)

noj said:


> I'll carefully read any other feedback, but if not, will try your approach, if I understand it. I think the only way to remove the convexity near the edge is to first grind the wide bevel dead flat (from shinogi to edge). After that, re-grind a secondary (larger) angle from lamination line to edge. Can that be done by just applying finger pressure near the edge? Setting that bevel consistently by hand, just a few degrees higher, would be a challenge.



This all sounds good. Finger pressure is the way to go here. Don't try to set and hold a steeper angle. I suppose if you want to end up with more convexity, you could do most of your thinning with finger pressure near the edge.


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## noj (Mar 6, 2022)

ian said:


> This all sounds good. Finger pressure is the way to go here. Don't try to set and hold a steeper angle. I suppose if you want to end up with more convexity, you could do most of your thinning with finger pressure near the edge.



When I mentioned finger pressure near the edge, I was proposing using it to promote the (larger angle) bevel between lamination line and edge. I have no clue how else to do it. Ideally, it (bevel between lamination line and edge) would not be convex. I suspect there will be a little convexity because it's done by hand (with imperfect skills). It would be akin to the method used to sharpen a single bevel if it didn't have this issue.


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## noj (Mar 6, 2022)

Here's the result after an hour on 400 grit stone. Looks like I need to get one with coarser grit.


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## noj (Mar 6, 2022)

Sadly, the convexity toward the edge isn't uniform. It's worse near the heel, as can be seen from the black marker. The left hand side of photo is nearest the heel. I know I didn't put it there because I can still see the micro-bevel.


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## Pie (Mar 6, 2022)

I say get a coarser stone sooner rather than later - the more strokes, the more time, the more chances to get lulled into the wrong angle and bung the whole thing up. (Also ask me how I know )

To my entirely untrained eye it looks like you may have a ways to go to get the heel part flat. One thing to note is if you want the whole thing proper flat, you will need to take care in removing steel evenly along the full length of the blade, as to avoid waviness of the bevel. 

Last thing is I’ve found my fingers quite poor at applying pressure to just the core steel. My solution is to use my fingernails to apply pressure as close to the edge as possible. It works quite well, but can leave marks in the steel. Keep this in mind re: what your ura looks like after all of this. 

Man, good luck, and I mean it with no sarcasm whatsoever. I’ve never gone this far on a single bevel before, and it looks terrifying.


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## noj (Mar 6, 2022)

Pie said:


> I say get a coarser stone sooner rather than later - the more strokes, the more time, the more chances to get lulled into the wrong angle and bung the whole thing up. (Also ask me how I know )
> 
> To my entirely untrained eye it looks like you may have a ways to go to get the heel part flat. One thing to note is if you want the whole the proper flat, you will need to take care in removing steel evenly along the full length of the blade, as to avoid waviness of the bevel.
> 
> ...



If you think this looks bad, here's what the edge looked like from the knife maker. I didn't grind it enough to change the geometry. I marked the edge with magic marker, and started it on a 1000 grit stone to see what I was dealing with. I gave up, and sent it in for professional repairs. The topics discussed here are all after that repair.

Edge as brand new:


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## noj (Mar 6, 2022)

A sideways question I have been asking myself, should I just get a different knife?

I am sure I can learn something from the process of fixing it. I enjoy learning more about sharpening, maintenance, technique (use).

That said, I am not a knife maker, and there's more injury risk.

It would make one of the world's most expensive garden tools though.


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## adam92 (Mar 7, 2022)

noj said:


> A sideways question I have been asking myself, should I just get a different knife?
> 
> I am sure I can learn something from the process of fixing it. I enjoy learning more about sharpening, maintenance, technique (use).
> 
> ...


I don't think you need a different knife, just need a coarse stone to save your time, I'm using Naniwa pink brick 220 grit for setting bevel/ fixing chips, SG 220 work fine as well.


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## Pie (Mar 7, 2022)

noj said:


> A sideways question I have been asking myself, should I just get a different knife?
> 
> I am sure I can learn something from the process of fixing it. I enjoy learning more about sharpening, maintenance, technique (use).
> 
> ...



For use? Maybe. For learning? This is a pretty good opportunity.. provided you enjoy putting in the time, I suppose. It’s already started as a project knife tho.


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## stringer (Mar 7, 2022)

noj said:


> A sideways question I have been asking myself, should I just get a different knife?
> 
> I am sure I can learn something from the process of fixing it. I enjoy learning more about sharpening, maintenance, technique (use).
> 
> ...



If you enjoy learning about this stuff then keep working on it. Get another one to check and compare your work after you've had a chance to make it your own in a few months or a year. You can't break it completely by just continuing to work on it with stones. Be patient. Be kind to yourself. No one is born a knife sharpener or knife maker. It takes time. Have fun. Keep asking lots of questions.


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## ian (Mar 7, 2022)

noj said:


> When I mentioned finger pressure near the edge, I was proposing using it to promote the (larger angle) bevel between lamination line and edge. I have no clue how else to do it. Ideally, it (bevel between lamination line and edge) would not be convex. I suspect there will be a little convexity because it's done by hand (with imperfect skills). It would be akin to the method used to sharpen a single bevel if it didn't have this issue.



Yea, that’s what I was saying. Usually with hamaguri sharpening you end up with the wide bevel divided into two flat-ish bevels of roughly equal size that are blended where they meet. You create the two angles by varying the placement of your finger pressure. I was just mentioning that since currently it’s quite thick behind the edge, if you want to save some effort and end up with more convexity (ie a bigger difference between the angles of those two bevels) than you usually get with hamaguri sharpening, you can thin while mostly keeping your finger pressure on the lower half of the wide bevel. If you do this, you may end up with more convexity than is typical on a single bevel, but if you don’t end up liking that you can of course keep going and flatten it.


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## noj (Mar 7, 2022)

ian said:


> Yea, that’s what I was saying. Usually with hamaguri sharpening you end up with the wide bevel divided into two flat-ish bevels of roughly equal size that are blended where they meet. You create the two angles by varying the placement of your finger pressure. I was just mentioning that since currently it’s quite thick behind the edge, if you want to save some effort and end up with more convexity (ie a bigger difference between the angles of those two bevels) than you usually get with hamaguri sharpening, you can thin while mostly keeping your finger pressure on the lower half of the wide bevel. If you do this, you may end up with more convexity than is typical on a single bevel, but if you don’t end up liking that you can of course keep going and flatten it.



I started down this path, albeit with a stone of too high grit. The problem I had was that the convexity (curvature) accelerated as you approach the edge, and most of it in the last 2 mm. If you apply finger pressure near the edge, there is no flat spot (natural angle) for reference. In fact there's air right underneath the edge. OK, stone slurry, not air;-) With no angle reference, I don't think I can do a good job by hand. So, I think I am stuck having to flatten it.


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## noj (Mar 7, 2022)

Thanks for the encouragement. I'll get a course stone, and see what I can do.

It may have been answered before, but I want to be sure I understand your ideas. Assume I flatten the entire bevel (shinogi line to edge). Should I set a second bevel from the lamination line to edge? If yes, how?

I think everyone said just finger pressure near the edge. Just checking my understanding. My guess is that procedure will tend to create a gentle convexity, simply because it's done by hand. Would it be best to create that second bevel by grinding it there with my course stone, or sort of let it evolve with normal sharpening.

Thanks in advance.


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## psfred (Mar 7, 2022)

Good thing I happened to take a peek at this thread. I'm fixing a yanagiba at the moment that had a rough secondary bevel on it when I got it (not an expensive knife or I'd have sent it back) that I proceeded to make very much worse by attempting to use my belt sander to remove the bulk of the excess bevel to get close enough to the edge. Big mistake, it was at the wrong angle and grabbed, so I've been grinding away off and on for a year and a half to fix it.

I'm using a King Deluxe 300, and having to "sharpen" the stone fairly often, the knife is very hard single steel and I have a huge amount to remove to fix my screw-up. What really speeds things up is some 60 grit silicon carbide loose grit on the stone and a minute or two of grinding with a piece of sandstone I'm flattening to use with straight razors and chisels. Once the 60 grit stops rolling freely I grind on the knife for a while keeping the slurry on the stone as long as I can -- it cuts VERY fast. Also keeps the 300 flat and cutting well. Don't do this if the 60 grit will reach the actual edge, as noted below.

I'll try to take a pic tonight, I'm approaching the edge after six or seven hours of grinding, total, on that 300 grit stone. The ura is in rough shape, but still deep enough I think I can get the edge properly sharp, it wasn't very deep or well executed, but then, again, this isn't an expensive knife. Cost enough I don't want to toss it, but not that high.

My advice, for what it's worth, is to grind on the coarse stone until you are near to where you want the secondary bevel to start, the switch to a finer stone (600 grit maybe) and approach but do not grind into the edge, when you are very close switch to a 1000 or 1200 grit stone and finish as per usual. The reason I suggest this plan of action is to avoid deep scratches at the actual edge. Coarse stone scratches at the edge are almost invariably accompanied by micro-cracks, and the very hard steel there will polish up nicely on the finer stones without removing them completely. In use the edge will chip easily as those cracks grow with stress. Takes longer, but I suspect the edge will last longer. Something I learned from honing straight razors, or at least trying to hone them. Diamond "stones" are the very worst at this, as the particles are very angular and make deep, V-bottom scratches.

For the actual geometry, probably pressure mid bevel until you switch to a finer stone, then edge pressure to get the slight convexity you want. That's what I will be doing when I get that far, still have way too much hard steel to grind off at the moment to worry about the edge profile yet, gotta get the gouges out first.


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## noj (Mar 7, 2022)

psfred said:


> [snip]



Thanks for the detailed write up, and especially the advice on course scratches near the edge. The problem though is I have it flat to the point where the secondary bevel should start. Because of the heavy convexity in the last 2 mm, I have no reference to set the secondary bevel. See photo above. If I place my fingers near the edge, there is no natural angle (no flatness whatsoever) to grind at. I know I don't have the skills to hold a 2 degree angle (or whatever the difference would be between the bevels) by hand. I tried that first. I think I have to grind it dead flat out to nearly the edge first. Other ideas welcome though.

I'm going to start with a Shapton Pro 120, and see how that works. I might try your trick with the silicon carbide grit if I have issues.

This knife was awful from the day it arrived. Neither the vendor or knife maker would accept a return, or even "re-sharpen" it.


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## ian (Mar 7, 2022)

noj said:


> Thanks for the detailed write up, and especially the advice on course scratches near the edge. The problem though is I have it flat to the point where the secondary bevel should start. Because of the heavy convexity in the last 2 mm, I have no reference to set the secondary bevel. See photo above. If I place my fingers near the edge, there is no natural angle (no flatness whatsoever) to grind at. I know I don't have the skills to hold a 2 degree angle (or whatever the difference would be between the bevels) by hand. I tried that first. I think I have to grind it dead flat out to nearly the edge first. Other ideas welcome though.
> 
> I'm going to start with a Shapton Pro 120, and see how that works. I might try your trick with the silicon carbide grit if I have issues.
> 
> This knife was awful from the day it arrived. Neither the vendor or knife maker would accept a return, or even "re-sharpen" it.



If you want to try something other than grinding a dead flat, rest it flat on the wide bevel, and then put your finger pressure as low down as you can without making the knife wobble. Steel will be abraded more quickly under your fingers, so you’ll eventually create some convexity. You could even keep pushing your fingers down lower when it seems like you can hold the angle without a wobble. 

All this will be easier on a coarse stone, though. With a faster stone, you’ll be able to cut in a much more uniform bevel, since you won’t have to hold the same angle for a billion strokes.


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## psfred (Mar 7, 2022)

I sympathize. Mine was barely usable out of the box, and after I screwed it up there wasn't any possibility of returning it even if the vendor would have taken a return. Profile was fine though, just a marked bevel at the edge which should not be there.

I could be wrong, but I was under the impression that a yanagiba should not have a secondary bevel of any size, just the convexity provided by pressure just behind the edge while sharpening, with the rest of the very wide bevel dead flat. In other words, if you can feel or see it, it's too big. 

That would mean more grinding for you, and a ton more for me!


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## noj (Mar 8, 2022)

psfred said:


> I sympathize. Mine was barely usable out of the box, and after I screwed it up there wasn't any possibility of returning it even if the vendor would have taken a return. Profile was fine though, just a marked bevel at the edge which should not be there.
> 
> I could be wrong, but I was under the impression that a yanagiba should not have a secondary bevel of any size, just the convexity provided by pressure just behind the edge while sharpening, with the rest of the very wide bevel dead flat. In other words, if you can feel or see it, it's too big.
> 
> That would mean more grinding for you, and a ton more for me!



I'll let folks with more experience than me answer the question about what the bevel is supposed to be.

What I was hoping for in a secondary bevel is a reference angle for sharpening the edge (and getting a burr) by finger pressure and placement near the edge. Specifically, only by finger placement, and not using a forced rotation from the wrist. If it helps making a better contrast between hagane and jigane, all the better.


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## SilverSwarfer (Mar 8, 2022)

I once had a seriously damaged yanagiba, and subsequently had opportunity to have it repaired professionally. The work was well done and I was able to repurpose the knife. However, I found myself in a similar situation as OP: I was dissatisfied with the new bevel profile. There was a hamaguri arc from shinogi to koba but the new setup was much thicker behind the edge and the microbevel was just obtuse beyond what I think/find to be useful.

The particular subject knife is honyaki and really pretty difficult to grind (this may be why the repaired condition ended up 'too thick'). My approach has been to chip away at the thinning and most importantly: raising of the shinogi line. If I can offer any advice it is to be patient and parse out your work over many sessions. Stop whenever you get fatigued or frustrated. Inspect your work often and use a sharpie if the scratch pattern is difficult to read.

Even if you end up less happy with the product of your work, you will definitely learn from the experience and develop your technique. IMO it's important to build enough skill to be able to raise your shinogi evenly and follow its original curve.



noj said:


> Sadly, the convexity toward the edge isn't uniform. It's worse near the heel, as can be seen from the black marker. The left hand side of photo is nearest the heel. I know I didn't put it there because I can still see the micro-bevel.



Some folks build a little extra convexity/thickness near the heel as a feature to fortify that region for tougher tasks that might cause chipping. Maybe the sharpener intended this?


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## noj (Mar 8, 2022)

SilverSwarfer said:


> [snip]



Thanks for sharing your experience and advice. I might not be terribly patient, but I do meter out my efforts. I can understand what you are saying about the thickness at the heel. There was no way I could get the edge in contact with the stone with finger pressure alone; I had to lift the blade. This was true for the whole blade, except near the tip, and worse at the heel. The original "sharpener" made the knife with a big fat frown in it, so my trust in their work is limited;-) I am not quite sure what to do with the idea about convexity near the heel. Maybe not grind that out flat?


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## SilverSwarfer (Mar 8, 2022)

noj said:


> Thanks for sharing your experience and advice. I might not be terribly patient, but I do meter out my efforts. I can understand what you are saying about the thickness at the heel. There was no way I could get the edge in contact with the stone with finger pressure alone; I had to lift the blade. This was true for the whole blade, except near the tip, and worse at the heel. The original "sharpener" made the knife with a big fat frown in it, so my trust in their work is limited;-) I am not quite sure what to do with the idea about convexity near the heel. Maybe not grind that out flat?


I had thought there was some professional intervention, post-frown?

RE: the heel, probably best to ignore the idea altogether! I was trying to offer an alternative possibility/explanation.


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## noj (Mar 8, 2022)

SilverSwarfer said:


> I had thought there was some professional intervention, post-frown?
> 
> RE: the heel, probably best to ignore the idea altogether! I was trying to offer an alternative possibility/explanation.



You are quite correct, I had the frown removed by a professional sharpener. I didn't ask them to change the bevel geometry, so I am guessing they just followed what was there.

My impression of the bevel as brand new is that it had this problem. It didn't feel right when cutting. When I tried taking it to a stone, it was such a mess, I couldn't say what I was dealing with:



https://www.kitchenknifeforums.com/attachments/ground-toward-edge-jpg.168845/



Then I put it on a flat surface, and saw the frown.


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## SilverSwarfer (Mar 8, 2022)

noj said:


> You are quite correct, I had the frown removed by a professional sharpener. I didn't ask them to change the bevel geometry, so I am guessing they just followed what was there.
> 
> My impression of the bevel as brand new is that it had this problem. It didn't feel right when cutting. When I tried taking it to a stone, it was such a mess, I couldn't say what I was dealing with:
> 
> ...


This pic reminds me of a couple Kitaoka K-tip yanis that I worked on a couple years ago... I found those 2 blades had pretty sloppy blade roads straight out of the box. You're most likely right: this knife had QC issues before the 1st owner introduced it to stones.


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## noj (Mar 8, 2022)

SilverSwarfer said:


> This pic reminds me of a couple Kitaoka K-tip yanis that I worked on a couple years ago... I found those 2 blades had pretty sloppy blade roads straight out of the box. You're most likely right: this knife had QC issues before the 1st owner introduced it to stones.



Ha, yes! That first owner was me. The picture is the knife brand new out of box, and all I had done was magic marker and a few swipes on a 1000 grit to see what I was dealing with.


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## SilverSwarfer (Mar 8, 2022)

How's the ura?


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## Bolek (Mar 8, 2022)

All that is just for curiosity as I do not have the level to re profile a single bevel. Why do you blend the two angles in Himaguri sharpening ? Aesthetic, tradition or a function ?


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## SilverSwarfer (Mar 8, 2022)

Bolek said:


> All that is just for curiosity as I do not have the level to re profile a single bevel. Why do you blend the two angles in Himaguri sharpening ? Aesthetic, tradition or a function ?


For me and my purposes, the primary benefit of hamaguri shape is enhanced food release. I suppose arguments could be made for all 3 reasons mentioned.


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## noj (Mar 8, 2022)

SilverSwarfer said:


> How's the ura?


The ura looks fine. It lost a little after the frown was removed. I haven't had to touch it yet as part of my work so far, with one exception. When brand new out of box, they had a micro-bevel on the ura side, which I promptly ground off.


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## Pisau (Mar 10, 2022)

noj said:


> This knife was awful from the day it arrived. Neither the vendor or knife maker would accept a return, or even "re-sharpen" it.





SilverSwarfer said:


> I once had a seriously damaged yanagiba,



Firstly, thanks for sharing your tales of woe fellas. I'm learning a lot. I'm also horrified by the level of customer service and terrified because thinning is inevitable someday. However, moving on... I immediately checked my relatively new yanagi and this is how a senior sharpener would leave his mark pre-honbadzuke, so this is stock ootb:







One more in opaque...






As you can see the whole blade road is convex but not much, notably on the jigane which is 4-7 mm from the edge (I am guessing where the thinning action should be). It's pretty much flat from the shinogi to the hazakai. The koba is like barely half a mm and there is not even an uraoshi. It's all migaki to the edge, I suppose he's leaving it up to you how to set it up...

Obviously this is just an anecdotal sample, but I can't help but be shocked by the level of the other "Sakai" blade!


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## noj (Mar 10, 2022)

Pisau said:


> [snip]



Thanks for those pictures and detailed observations. What you described is about what I was expecting. Looking at the light reflection in the first photograph, the convexity appears both small and uniform. On mine, the curvature rapidly accelerates toward the edge. Yours doesn't have a perfectly flat area on the jigane, but close enough to be able to reach the edge and maintain an angle while sharpening with finger pressure alone.

For those interested, here's how the whole saga started ..






expectations and experiences with new blade


I have a question on expectations for sharpening when purchasing a new knife. I am well aware that the final edge finishing (or more) may be left to the chef. My question pertains to the shaping of the blade and bevels that will become an issue when sharpening. Specifically, imperfections...




www.kitchenknifeforums.com


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## noj (Mar 10, 2022)

Pictures and observations after an hour an 120 grit, comments welcome.

First, it's going to take a while to get rid of that thick convexity behind the edge, even with 120 grit. The stone loaded up a couple times.

The forward 1/2 - 2/3 seem to be going well. The width of the overly convex area (ie measured parallel to blade road) is larger near the heel. I might be having some issues with what to do in the first 1/3 of the blade from the heel.. If I place my fingers at even the a little from the edge, I hit the shinogi. If I place my fingers really close to the edge, I am concerned I may start grinding just near the edge before I am ready.

As I reach the forward 1/3, I can place my fingers over the hazakai and not hit the shinogi.


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## psfred (Mar 10, 2022)

Those last two pics look a lot like the condition of my knife at the moment. I finally got out my much too soft "golden tiger" 220 grit stone and sacrificed a couple mm of it. With lots of mud and very little pressure (and lots of flattening) I'm about as close to the edge as you are. Mine is rougher, but so far only slightly convex with a steep bevel to the very rough edge. 

Bought a couple stones today -- Naniwa "traditional" 220 in silicon carbide that is hopefully somewhat harder than my mud stone, and a Naiwa Green Brick to replace my blue synthetic aoto that has been glued together twice now.

I should be able to get the grinding done this weekend -- the mud from the 220 works wonderfully on my King Deluxe 300! Very gritty and very fast -- and it stays flat, unlike the 220 grit stone. I think you can rub grit off with your thumb on that stone, it's by far the softest one I've ever used, even worse that a Naniwa Superstone 220.

You will have to decide how much of that convexity you are willing to grind off this moment -- eventually you will get it all gone as you sharpen repeatedly, but I don't want to grind off steel without a good reason. If the knife cuts well with some extra convexity at the heel I'd leave it rather than grind a lot of steel off the rest of the blade and end up needing to restore the ura.


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## noj (Mar 16, 2022)

Still working at it. The stones were a bit of a surprise. The Shapton Pro 120 is very slow to release grit. I could go a rather long time with what felt like 1-3 course rocks and nothing else under the blade. It worked quite well when I forced a slurry first though. As one might expect, the stone is very slow to dish. The Shapton Pro 340 (my next step) was totally different. It releases a sandy grit very fast. A pleasant contrast to the 120, until you look at how fast it dishes. At this point, I may be close to the limit of what I can do with the 340 grit and not eat into the edge. The dark spot near the heel is just a water mark.


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## noj (Mar 16, 2022)

Hours on the 1000 grit, but I can't get to the edge. I cleaned it up a little to see what it looked like, but the edge is still ragged. The ura wasn't on the 1000 grit, obviously.


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## Forty Ounce (Mar 18, 2022)

noj said:


> Hours on the 1000 grit, but I can't get to the edge. I cleaned it up a little to see what it looked like, but the edge is still ragged. The ura wasn't on the 1000 grit, obviously.View attachment 170210


You mentioned that lifting the knife would make the problem worse, but that's not the case. You'll need to carefully lift, just a tiny bit, to get rid of the large bevel just behind the edge and then lay it down a little and grind, then a little more, and grind more, til you have the geometry that you want. It's not easy, but that's how it's done.


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## Forty Ounce (Mar 18, 2022)

This is for grinding a sword, but should give you an idea of how to grind in sections. Blend them together afterwards.


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## noj (Mar 18, 2022)

Forty Ounce said:


> You mentioned that lifting the knife would make the problem worse, but that's not the case. You'll need to carefully lift, just a tiny bit, to get rid of the large bevel just behind the edge and then lay it down a little and grind, then a little more, and grind more, til you have the geometry that you want. It's not easy, but that's how it's done.



Interesting. Seems to be different advice from what I heard/understood so far. What grit would you start the process based on where I left off? I have about 1 to 1.5 mm of unfinished area at the edge.


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## noj (Mar 18, 2022)

Forty Ounce said:


> This is for grinding a sword, but should give you an idea of how to grind in sections. Blend them together afterwards.
> View attachment 170506



One question on the photo. After being ground in that way, can the knife be sharpened "normally"? My that I mean just using finger pressure near the edge to get a burr as shown in Jon's (of JKI) videos. I ask because the profile in the picture (as envisioned for a single bevel of course) gets increasingly convex near the edge. It was exactly that feature I was trying to remove because it couldn't be sharpened (as I understand it "normally"). There was no preferred angle I could achieve near the edge; I could get "any" angle depending on minor (and not easily repeatable) finger placement and pressure.


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## Forty Ounce (Mar 18, 2022)

noj said:


> Interesting. Seems to be different advice from what I heard/understood so far. What grit would you start the process based on where I left off? I have about 1 to 1.5 mm of unfinished area at the edge.


Depends on how fast you want to do it and how you are on the stones. Coarse would be my preference, but if you do it wrong, you can do more damage than good. Keep in mind that when lifting that you don't lift too much. You should only be removing material down to the edge, forming a burr means you're going too far. This is assuming that you've already got a profile that you're happy with, otherwise you'd want to correct that before thinning.


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## Forty Ounce (Mar 18, 2022)

noj said:


> One question on the photo. After being ground in that way, can the knife be sharpened "normally"? My that I mean just using finger pressure near the edge to get a burr as shown in Jon's (of JKI) videos. I ask because the profile in the picture (as envisioned for a single bevel of course) gets increasingly convex near the edge. It was exactly that feature I was trying to remove because it couldn't be sharpened (as I understand it "normally"). There was no preferred angle I could achieve near the edge; I could get "any" angle depending on minor (and not easily repeatable) finger placement and pressure.


That photo is not meant to be copied. It's just an example of how to grind in facets before blending.


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## noj (Mar 19, 2022)

Forty Ounce said:


> Depends on how fast you want to do it and how you are on the stones. Coarse would be my preference, but if you do it wrong, you can do more damage than good. Keep in mind that when lifting that you don't lift too much. You should only be removing material down to the edge, forming a burr means you're going too far. This is assuming that you've already got a profile that you're happy with, otherwise you'd want to correct that before thinning.



Thanks for all the interesting information and advice. I'll have to ponder what stone to start the next phase on.

Ian suggested using a course stone because you avoid having to hold a precise angle through many strokes. psfred said to be careful using a course stone in contact with the edge. With only 1-1½ mm of rough area left, it will be a delicate balance. I may start with a 1000 grit just to get the feel of the process, and correct mistakes before I remove much metal. If it needs more work, I can switch to a courser stone.

One last question before I start this phase. There is a small wobble in the edge where it should be dead flat. In this case, I mean holding the knife perpendicular to a flat surface (back side of Atoma plate) and looking for light from behind. I can't really measure it, but I would guess it's off by only a 1-2 mil (0.001 inch). The rough area at the edge isn't 100% uniform either, though much improved; it's wider in the middle part of the blade. Would it make sense to start with a very flat stone, and create a uniform and known high (angle = TBD) bevel, and correct some of the irregularity first?


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## Forty Ounce (Mar 19, 2022)

noj said:


> Thanks for all the interesting information and advice. I'll have to ponder what stone to start the next phase on.
> 
> Ian suggested using a course stone because you avoid having to hold a precise angle through many strokes. psfred said to be careful using a course stone in contact with the edge. With only 1-1½ mm of rough area left, it will be a delicate balance. I may start with a 1000 grit just to get the feel of the process, and correct mistakes before I remove much metal. If it needs more work, I can switch to a courser stone.
> 
> One last question before I start this phase. There is a small wobble in the edge where it should be dead flat. In this case, I mean holding the knife perpendicular to a flat surface (back side of Atoma plate) and looking for light from behind. I can't really measure it, but I would guess it's off by only a 1-2 mil (0.001 inch). The rough area at the edge isn't 100% uniform either, though much improved; it's wider in the middle part of the blade. Would it make sense to start with a very flat stone, and create a uniform and known high (angle = TBD) bevel, and correct some of the irregularity first?


If this is your first single bevel project, I'd say just leave it and correct it later on. Since yanagi aren't used on the board in the same way that gyuto are, it's not crucial that the profile is perfect.. a little recurve is no big deal. It's fun chasing perfection, but it can be maddening.


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## noj (Mar 19, 2022)

Forty Ounce said:


> If this is your first single bevel project, I'd say just leave it and correct it later on. Since yanagi aren't used on the board in the same way that gyuto are, it's not crucial that the profile is perfect.. a little recurve is no big deal. It's fun chasing perfection, but it can be maddening.



Thanks. Not my first single bevel sharpening, but never had to re-grind the whole thing before.

I've thinned double bevels, but that's another topic.


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## natto (Mar 19, 2022)

noj said:


> It may have been answered before, but I want to be sure I understand your ideas. Assume I flatten the entire bevel (shinogi line to edge). Should I set a second bevel from the lamination line to edge? If yes, how?


This only works if there is no taper. Please check the spine. My usuba only has about .5mm taper, hard to see with naked eyes. Edge and shinogi beeing parallel means the angle inreases a little from tip to heel. Flattening the whole bevel will move up the shinogi at the heel or shorten the bevel at the tip.

Please don't ask how I know.


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## noj (Mar 19, 2022)

natto said:


> This only works if there is no taper. Please check the spine. My usuba only has about .5mm taper, hard to see with naked eyes. Edge and shinogi beeing parallel means the angle inreases a little from tip to heel. Flattening the whole bevel will move up the shinogi at the heel or shorten the bevel at the tip.
> 
> Please don't ask how I know.



Thanks, and I hope your usuba feels better now;-)

Yes, there is a small taper (I measured with micrometer just before the shinogi). I think that explains why the bevel at the heel was getting ground, as if something was amiss, and in fact it was. Thankfully, I now have a method (from member natto) to get the secondary bevel started, and I can hopefully steer clear of any further issues there. My shinogi is only 1 mm taller at the heel vs tip, so hopefully isn't noticeable.


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## noj (Mar 19, 2022)

noj said:


> [snip]



I gave it (ie suggestion from member natto) a try, and it looks promising. I spent 90 min on a 400 grit. Sounds like a lot of time, but it wasn't all grinding. I went slow, used magic marker several times, examined, thought about the process and what I observed, etc. The rough junk is gone, looks like a gentle convexity from lamination line to edge. For the first time, I can apply just finger pressure and grind at the edge, and not scrape the shinogi at the heel, and it sounds "good" on the stone. I need a bit more work on the last 5 mm of the tip, and I'll see if I can finish the job. But I have had enough for today.


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## natto (Mar 19, 2022)

You are pretty fast. thumbs up


noj said:


> Thanks, and I hope your usuba feels better now;-)


Thank you, I am fine with that trainig knife. My initial idea was to sharpen the bevel flat on the stone, you see? But my memory saves the moment I got it sorted out, not hours of grinding bad to worse. The topic is explained on a vid in the awesome thread.


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## noj (Mar 19, 2022)

noj said:


> I gave it (ie suggestion from member natto) a try, and it looks promising. [snip]



Oops .. the suggestion from Fourty Ounce was the main one that was tried here. Specifically:

" You'll need to carefully lift, just a tiny bit, to get rid of the large bevel just behind the edge and then lay it down a little and grind, then a little more, and grind more, til you have the geometry that you want. "

Tips from natto used also.


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## M1k3 (Mar 19, 2022)

natto said:


> You are pretty fast. thumbs up
> 
> Thank you, I am fine with that trainig knife. My initial idea was to sharpen the bevel flat on the stone, you see? But my memory saves the moment I got it sorted out, not hours of grinding bad to worse. The topic is explained on a vid in the awesome thread.


Togitogi?


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## natto (Mar 21, 2022)

noj said:


> Oops .. the suggestion from Fourty Ounce was the main one that was tried here.


Yes, my point was about geometry. But anyway



M1k3 said:


> Togitogi


??? Would you mind to explain?


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## noj (Mar 21, 2022)

natto said:


> Yes, my point was about geometry. But anyway
> [snip]



Your comments on geometry were most helpful. It prevented me from grinding away at what I thought was a problem, but in fact wasn't. That kept me from creating a new problem.

I was at a point in the process where I was not able to make progress on a second bevel (or convexity) from lamination line to edge using finger placement/pressure alone. I got un-stuck using the suggestion from Fourty Ounce.

Hopefully that clarifies, Thanks again.


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## natto (Mar 21, 2022)

noj said:


> Hopefully that clarifies, Thanks again.


Sorry, poor english here. But you are right. I was not sure wether you got the whole picture. Nice to hear you got it.

Thank you too


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## noj (Mar 21, 2022)

Next question ...

I think I have the bevel geometry about right. I am having some trouble removing all the roughness (micro-chips) at the edge. I have noticed that I can sharpen on a 1000 grit, feel an even burr, and remove it (ura with 8000 grit), yet the edge isn't clean. It is hard to even see the problem until I go to finer grit, so it's taking a lot of time. A microbevel doesn't remove it (because I wasn't going to make it more than micro). I have been over it 3 times already, and it may be improving. It is cutting cleaner each time. I haven't gone back to a courser stone because I was afraid of making it worse. Suggestions? Otherwise, I'll just keep going on this path until I get it. Latest picture below, but I don't really have a good way for you to see the rough edge, and anyhow, you know what that looks like.


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## Forty Ounce (Mar 22, 2022)

noj said:


> Next question ...
> 
> I think I have the bevel geometry about right. I am having some trouble removing all the roughness (micro-chips) at the edge. I have noticed that I can sharpen on a 1000 grit, feel an even burr, and remove it (ura with 8000 grit), yet the edge isn't clean. It is hard to even see the problem until I go to finer grit, so it's taking a lot of time. A microbevel doesn't remove it (because I wasn't going to make it more than micro). I have been over it 3 times already, and it may be improving. It is cutting cleaner each time. I haven't gone back to a courser stone because I was afraid of making it worse. Suggestions? Otherwise, I'll just keep going on this path until I get it. Latest picture below, but I don't really have a good way for you to see the rough edge, and anyhow, you know what that looks like.
> 
> View attachment 171015


Are you alternating between the back and front when deburring?


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## noj (Mar 22, 2022)

Forty Ounce said:


> Are you alternating between the back and front when deburring?



Yes.

Almost always on 8000 grit for the ura. I used a 3000 once after the initial rework because the edge was worse.

For better or worse, I cleaned up the edge with microbevel, which I then polished. The microbevel is larger than I prefer (for single bevel). I think the knife can be used as-is for now. As I get more inspiration or ideas, I can see if it sharpens normally.


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## natto (Mar 23, 2022)

noj said:


> I have been over it 3 times already, and it may be improving.


That's good news.

Heat treat on the hard side not only allows micro chipping. The chips might indicate micro cracks. And cracks can grow further up. It's just one way to look at this compromised materal above the edge.

I checked this on my double bevel. It took some serious sharpening to get rid of this problem. Touch ups or usual sharpening didn't work. The knife is a Mizuno white 2, so nothing crazy hard.

Good news is, after removing compromised material the knife improved. My initial sharpening didn't remove enough material. 

And Korin got a vid, mentioning ura sharpening and brittle edges.
*Learn How To Sharpen: Episode 11 - Deba Basics*


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## Forty Ounce (Mar 23, 2022)

noj said:


> Yes.
> 
> Almost always on 8000 grit for the ura. I used a 3000 once after the initial rework because the edge was worse.
> 
> For better or worse, I cleaned up the edge with microbevel, which I then polished. The microbevel is larger than I prefer (for single bevel). I think the knife can be used as-is for now. As I get more inspiration or ideas, I can see if it sharpens normally.


It kinda sounds like you just have some residual burr left. This is a guess, ofc, since I can't check it out in person, but I'd keep going and see if it improves


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## Forty Ounce (Mar 23, 2022)

natto said:


> That's good news.
> 
> Heat treat on the hard side not only allows micro chipping. The chips might indicate micro cracks. And cracks can grow further up. It's just one way to look at this compromised materal above the edge.
> 
> ...


Dunno that I'd recommend that deba video.. Korin vids tend to not be great.


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## adam92 (Mar 23, 2022)

Forty Ounce said:


> Dunno that I'd recommend that deba video.. Korin vids tend to not be great.


I follow Jon technique in his sharpening video on YouTube, so far everything is good, great vendor!


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## noj (Mar 23, 2022)

Forty Ounce said:


> It kinda sounds like you just have some residual burr left. This is a guess, ofc, since I can't check it out in person, but I'd keep going and see if it improves


I think so too. At least with a clean microbevel, now I can more clearly see what I am doing. Hopefully, the micro chips/cracks have been ground off. If they reappear, I will have to re-evaluate. I have been following Jon's (of JKI) videos.


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## Forty Ounce (Mar 23, 2022)

Good. Korin videos are evil.


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## noj (Mar 26, 2022)

What I seem to be seeing is and edge that is too fragile to hold up. I apply a microbevel (very gently). I see, maybe even feel, "microchips" after deburring on ura (tried 3 different stones on ura 8000 grit or more). Tried refining microbevel with different stones, and more deburring on ura. Tried a tiny bit more convexity near edge. When I say "microchips", what I usually see is a clean microbevel away from the edge, but as I turn the knife towards the edge I can see issues. I know that means the microbevel isn't perfectly flat, but it looks pretty good. The microbevel is about 40 degrees. The steel is supposed to be blue 2 [corrected, said 1].

[begin rant] Repeat .. repeat .. repeat. It's sharp, but can't get it clean. Even if I get it right, I am worried it may be to fragile to actually use. I can't have a knife that goes dull cutting paper, only to spend 20h to sharpen it again. [end rant] ;-)


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## psfred (Mar 26, 2022)

Lol, I understand. I got mine ground down to the edge, but it still had enough nicks in that edge I'll have to go back to the 220 grit stone for a while. Cuts well considering the edge condition and it's inherent cheapness.

An unstable edge on a new knife isn't uncommon, and if it ever met power tools during manufacture, the very edge can be either de-tempered or de-carbonized. More grinding away of the edge will fix that as you get to good steel pretty quick. This is also true for straight razors. Initial edge may fail pretty fast. 

And grinding to the actual edge with a coarse stone or wheel at high pressure in hard high carbon steel will give you fits with microcracks until you grind the damaged steel off.

Straight razor users strongly recommend NOT using paper to test an edge, it's abrasive enough to make a straight uncomfortable just slitting a single sheet, so that may not be a good test for your knife. And then it may be a stressed edge and it's gonna fail repeatedly until you grind off the bad part -- sadly, on single bevel knives, that's a huge amount of work!


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## noj (Mar 26, 2022)

Well, it's had 2 mm ground off the edge before I even started on it. It came brand new out of box with a 2 mm frown (and other high/low spots near the edge). I sent it off to be professionally repaired. The frown was fixed, but it was so thick behind the edge, it was worse that useless. I have been doing more grinding of the edge now for 2 weeks. Not full time, but several revisions. I am starting at 1000 grit at this point.

I never actually saw it get dull cutting paper;-) As a kitchen tool, it's got to be tougher than that for my taste.


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## Rangen (Mar 26, 2022)

Straight razor users are paranoid about their ultrathin, delicate edges. I know, I am one. For knives, don't worry about paper unless you're going to shave with them.


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## psfred (Mar 26, 2022)

I agree, edges that chip really easily are not good for kitchen use. I have to be careful with my Tojiro DP paring knife, I've chipped it by twisting it by accident while slicing up orange skins to candy them. Big pain to grind out.

With that much ground off it may just not be a good example -- or it needs to be re-tempered to drop the hardness at the edge some.


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## noj (Mar 26, 2022)

I can't re-temper it. Maybe just sell it.


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## BoSharpens (Mar 27, 2022)

noj said:


> I can't re-temper it. Maybe just sell it.



Buyer won't like it either. I've had to take 3 mm off a single bevel to get back to "virgin metal edge temper". What caused it during manufacture or afterwards I can't say, but the edge constantly fractured & flaked off.

It was a pain, but once I redid the final edge it cut fine. No, I'm not talking a literal razor edge, but it was great for cutting on a normal PP or Maple board.


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## Feiii (Mar 27, 2022)

noj said:


> I have a new-ish single bevel knife, and a question on sharpening.
> 
> The knife, as new, was ground so badly, I sent it off for professional help. They did a good job of fixing the major problem: the entire flat section had a significant frown. It may have had other issues, but it was hard to tell with the frown. The knife came back with the frown gone, and nice flat surfaces (no concave spots).




I have a question about this. Shouldn’t the flat side be concave with traditional knifes? It shouldnt be flat flat. Right?


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## noj (Mar 27, 2022)

Feiii said:


> I have a question about this. Shouldn’t the flat side be concave with traditional knifes? It shouldnt be flat flat. Right?


By flat, I meant the side profile, not the bevel.


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## Pisau (Mar 28, 2022)

Seems pretty close to your problem on a Suisin blade. I am aware that Sakai Takayuki (Aoki hamono) is different from Suisin (Junro Aoki & Son), but are they somehow related? Was the grind "error" intentional? Could there be something lost in translation somewhere, like their own style of hamaguri or something?



noj said:


> I sent it off to be professionally repaired. The frown was fixed, but it was so thick behind the edge, it was worse that useless.



I don't mean to knock anyone, but personally I would not send a complex job like this to a retail shop. Mate, how about sending your knife to CO? It'd be interesting what Yosuke-san can come up with...


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## noj (Mar 28, 2022)

Pisau said:


> Seems pretty close to your problem on a Suisin blade. I am aware that Sakai Takayuki (Aoki hamono) is different from Suisin (Junro Aoki & Son), but are they somehow related? Was the grind "error" intentional? Could there be something lost in translation somewhere, like their own style of hamaguri or something?
> 
> 
> 
> I don't mean to knock anyone, but personally I would not send a complex job like this to a retail shop. Mate, how about sending your knife to CO? It'd be interesting what Yosuke-san can come up with...




Thanks for the tip. The video was interesting too. I never heard of him before, and there are few references I found on the forum.

The original problem (new out of box) was a 2 mm frown across the whole blade, plus low (convex) spots at the edge, plus a (not very micro) microbevel on both sides. Yes, the ura had a microbevel. I could not evaluate too much of any hamaguri style, or even sharpen it. I did get the impression that it was very thick and convex behind the edge. Neither the retailer or Aoki hamono would help. I had it repaired where I did based on recommendations from the forum. Upon return, the frown was gone, but as I said, the hamaguri was very steep and thick near the edge. I was not able to sharpen it with that geometry, it didn't cut well with that geometry. In order to be useful to me, I need to be able to sharpen it with techniques I understand (ie Jon's videos from JKI). I suspect the geometry was original (vs changed when I had it repaired). I have no way of determining if it's some maker's style or not.


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## Forty Ounce (Mar 28, 2022)

noj said:


> I can't re-temper it. Maybe just sell it.


Before you do that.. send it to me and I'll see if I can put an edge on it. If you pay for shipping, I won't charge ya.


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## noj (Mar 28, 2022)

Forty Ounce said:


> Before you do that.. send it to me and I'll see if I can put an edge on it. If you pay for shipping, I won't charge ya.


That's very generous of you. I'll message you shortly (next couple days).


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## noj (Mar 29, 2022)

More questions .. and not signaling anything different from what I said.

I still don't know where the micro-chips at the edge post-sharpening are coming from.

What should the edge look like before applying a microbevel? It's effectively a razor edge, but I have never gotten it "perfect". Specifically, I can see shiny spots on the edge in bright light (after burr removal from ura work). Before the ura work, it's hard to be sure what I am looking at because of the burr.

What should I expect to feel while doing the ura? I have a couple stones of 8000 grit and above I have tried, all carefully flattened and clean. I try to use just enough pressure to keep the blade flat and not hydroplane. I get a sensation that feels a little rough. I could imagine bits of burr on the surface. Cleaning the stone and repeating doesn't change anything much. What is expected about water/slurry on the stone during the process? The first pass towards the edge acts like a squeegee.

I wonder if applying the microbevel is causing damage to the edge. I use a very light pressure; I can't imagine less, and still have proper angle and pressure control. Whether I use a 5000 or 8000+ grit didn't seem to matter. Is it correct to start at the final angle you want? That's what I have been doing. I can imagine steaking up on it, but I think I would get a wide round "less-micro" bevel.


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## Forty Ounce (Mar 29, 2022)

noj said:


> More questions .. and not signaling anything different from what I said.
> 
> I still don't know where the micro-chips at the edge post-sharpening are coming from.
> 
> ...


Have you checked the blade for straightness? The coarse feeling could be from it being bent.


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## noj (Mar 29, 2022)

Interesting. I set the ura on the backside of my Atoma, and there's at least 1 mm (could be 2, just eyeballed it) deflection away from the Atoma. I was careful to place the heel at the edge of the Atoma, so this isn't due to something funky near the handle.


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## Forty Ounce (Mar 29, 2022)

noj said:


> Interesting. I set the ura on the backside of my Atoma, and there's at least 1 mm (could be 2, just eyeballed it) deflection away from the Atoma. I was careful to place the heel at the edge of the Atoma, so this isn't due to something funky near the handle.


Well.. that sucks. Good news though, I can fix that easily (again, no charge)


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## natto (Mar 30, 2022)

Forty Ounce said:


> Well.. that sucks. Good news though, I can fix that easily (again, no charge)



I appreciate your offer and this kind forum. 

Years ago I got stuck with my first and only single bevel. Thought about this and that or buying another one. But the initial idea was to learn single bevel sharpening. So I'ld have been disappointed with having to send it out to repair.


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## natto (Mar 30, 2022)

@noj
Because of this thread I took my usuba out of the project box. Thank you 

So far it looks like I am able get the ura straight again. Have to recheck it today with less pressure.


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## natto (Mar 30, 2022)

M1k3 said:


> Togitogi?


You puzzled me. But yes, it was Togitogi.

TOGITOGI, or why the kireha can't be flat.

This video and the previous ones, about checking the ura and the front bevel in relation got me going.


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## noj (Mar 30, 2022)

Forty Ounce said:


> Well.. that sucks. Good news though, I can fix that easily (again, no charge)


PM sent, thanks again.


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## Forty Ounce (Mar 30, 2022)

natto said:


> I appreciate your offer and this kind forum.
> 
> Years ago I got stuck with my first and only single bevel. Thought about this and that or buying another one. But the initial idea was to learn single bevel sharpening. So I'ld have been disappointed with having to send it out to repair.


I completely understand that feeling.. but I also know just how difficult it can be to learn when the knife isn't straight. I figured that I could help get it ready for a proper learning experience.


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## noj (Apr 8, 2022)

Forty Ounce sharpened it for me, and provided some good feedback. Apparently, the thinning I did was pretty good, but the microbevel I used wasn't big enough, leaving the edge way too thin.

I was surprised videos don't seem to cover this aspect (much), or the balance between work on the wide bevel vs microbevel.

Thanks Forty Ounce, and everyone for all the help.


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## psfred (Apr 9, 2022)

That's good news. 

All of life is a learning experience I've found, and I expect to screw things up the first time I do something. Sounds like you got very close on the first try!


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## mengwong (Nov 21, 2022)

For closure, could you share a photo of the “after”?


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## noj (Nov 21, 2022)

Sure. I still haven't used or modified the knife. Sorry if my pictures aren't great, it's all my phone does. One photo hopefully shows the micro bevel Forty Ounce added. The other shows the overall finish. There are scratches in the area where the hagane and jigane meet that may indicate a low spot. I don't know if this came from the maker, or perhaps swarf buildup when I was working on it.


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## mengwong (Nov 21, 2022)

Thanks. It’s been super interesting to follow the progress of your project. I’ve been thinning my double-bevel gyuto and sujihiki recently and getting more confident about returning to the single-bevels. I’m learning to read the convex profile of the bevel by tilting the edge under the light so the reflection tells the curve. I know the other method is horizontal blinds but I don’t have those handy. Under the microscope, though, quite a lot is visible. That and calipers and vaguely obscene pinching of behinds. Behind the edge, that is.


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## mengwong (Nov 21, 2022)

noj said:


> The video was interesting too.


I’d give two thumbs up to this video except I had to sit on my hands, watching him slice up and bleed out his left thumb, oh man. It’s like the pessimal midpoint between the thumbnail test and the three-finger test.


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## noj (Nov 21, 2022)

And just for fun, here's a photo again of how it all started. The picture was the knife brand new, except I colored with magic marker, and started it on a 1000 grit stone to see what I was dealing with.


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## ahhactive (Nov 22, 2022)

Forty Ounce said:


> This is for grinding a sword, but should give you an idea of how to grind in sections. Blend them together afterwards.
> View attachment 170506


Wow i got enlightened! Thanks!!


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## ahhactive (Nov 22, 2022)

Im also attempting to polish my single bevel. But i still got messy in the middle of the kireha and a big low spot right near the tip. Question: i know a small microbevel helps the integrity of the edge but a yanagi is used unlike a gyuto where its not slamming too much on the board. What are the common guidelines?


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## ethompson (Nov 22, 2022)

Avoid adding the micro-bevel unless it starts to chip on you. With a good board and proper use chipping shouldn’t be an issue at a “zero edge.”


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## ahhactive (Nov 22, 2022)

ethompson said:


> Avoid adding the micro-bevel unless it starts to chip on you. With a good board and proper use chipping shouldn’t be an issue at a “zero edge.”


Sweet. However is too thin an issue for zero grind? I felt mine was a tad thin. How do i tell?



This is the finish from your shiro suita btw!


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## noj (Nov 22, 2022)

If it matters, my blade would not "take" a zero grind. By that, I mean the edge was full of micro-chips. I tried different stones, worked both the bevel and ura, used a very light pressure, etc. I repeated the whole process from a medium grit multiple times. It's not exactly a fair comparison, but none of my double bevel knives have this problem.


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## Lurkernomore (Nov 30, 2022)

ahhactive said:


> Im also attempting to polish my single bevel. But i still got messy in the middle of the kireha and a big low spot right near the tip. Question: i know a small microbevel helps the integrity of the edge but a yanagi is used unlike a gyuto where its not slamming too much on the board. What are the common guidelines?


Is that a Byakko?

That’s not a low spot, that’s just slight convexity and you not following the radius of the upward curve. You can follow it by adjusting your finger placement. You may also need to raise your right hand slightly just like when doing the tips of gyutos. 

Many yanagi come with a secondary bevel out of the box. That’s why you do honbazuke. A small microbevel can help with retention and chippy blades and it also speeds up touch ups when you got work to do and have absolutely no time to whip out the stones. Touch up your microbevel on the finisher and go. The downside is that you can only do that so often before the bevel fattens up and you have to do a serious sharpening session.

OP‘s Mukimono was also fine, as demonstrated by a competent sharpener. They’re notoriously hard to sharpen, up there with Kama usuba. I have messed up one as well, didn’t post that on any forum though. Getting a mukimono when you have no idea what you’re doing is a great recipe for a bad time.


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## noj (Nov 30, 2022)

Very little of the OP's knife was fine;-)

1. came new with
- big frown
- low/high spots going to the edge
- very think behind edge
- large "micro" bevels on both sides
2. sent out to sharpener to fix
- decent job, but still way too thick behind edge 
3. lot's of work on my part, with good advise here
- edge won't take a zero grind without lots of micro-chips, and 
- my micro-bevel not big enough to compensate
4. Forty Ounce kindly helped
- added more micro-bevel
- may have straightened blade


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## Lurkernomore (Dec 1, 2022)

Forty ounce did a great job. I very much believe he could do a great job because the knife was fundamentally solid. Crisp shinogi indicating no low spots on the hira and I have yet to see a wavy back on a nishimura grind.

Maybe you need another one, forged and ground by a completely different set of craftsmen. Getting for example a Masamoto KS one would put things into perspective. Owning and sharpening different knives of each type gave me a frame of reference and that’s really the most important thing.


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## noj (Dec 1, 2022)

I am not sure you are following the story. 

Did you read how it started out? The photos show some of the issues. The final pictures are the result of my work, with the exception of the work done by Forty ounce, plus another knife shop grinding off the frown, and hopefully adjusting the bevels accordingly.

I had to remove a lot of steel after the frown was ground off. It was so thick behind the edge, it not only didn't cut well, it couldn't be sharpened normally. Specifically, finger (or even finger nail) pressure couldn't get the edge to the stone.

Yes, Forty Ounce generously made a larger clean micro-bevel (and possibly straightening). This was the last step giving me trouble because the edge had micro-chips, and my small micro-bevel wasn't removing them.

For worse or better, the steel will not take a zero grind without a lot of micro-chips, no matter how gentle I was.

Sorry if I am repeating myself.


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## ahhactive (Sunday at 4:50 AM)

Lurkernomore said:


> Is that a Byakko?
> 
> That’s not a low spot, that’s just slight convexity and you not following the radius of the upward curve. You can follow it by adjusting your finger placement. You may also need to raise your right hand slightly just like when doing the tips of gyutos.
> 
> ...


Yes this is a byakko, love it great price great product! Ok i will attempt again. Thank you for the advice!


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