Any honbazuke advice?

[Qapla']

Hi all,

For those who deal with Japanese single-bevel knives, I have some questions for you regarding initial sharpening:

- When doing honbazuke (i.e., grinding out every last accursed high/low spot with the roughest stones one has), how much shinogi-raising should be involved and how much uraoshi should be done?
- How do I find out how to access the parts I'm missing? I use Jon Broida's technique of permanent-marker on the blade, but there are some spots that just don't go away even after hours with a Atoma 140 plate or a Shapton 120 stone, even if I try to press on those areas. (This seems especially difficult at areas near the point of a yanagiba or the "lead area" of a kama-gata usuba; somehow common-sensical "put the damned area in contact with the stone and make the damned passes" just doesn't seem to work._

Thanks all for any advice.

 

[Michi]

The Korin sharpening series includes videos for sharpening yanagiba, deba, and usuba. This might be useful regarding the uraoshi.

https://www.youtube.com/playlist?list=PLsSxXLQSZIe__A5THcrFGto9_PSkXWiN6

Michi.

 

[JBroida]

Hi all,

For those who deal with Japanese single-bevel knives, I have some questions for you regarding initial sharpening:

- When doing honbazuke (i.e., grinding out every last accursed high/low spot with the roughest stones one has), how much shinogi-raising should be involved and how much uraoshi should be done?
- How do I find out how to access the parts I'm missing? I use Jon Broida's technique of permanent-marker on the blade, but there are some spots that just don't go away even after hours with a Atoma 140 plate or a Shapton 120 stone, even if I try to press on those areas. (This seems especially difficult at areas near the point of a yanagiba or the "lead area" of a kama-gata usuba; somehow common-sensical "put the damned area in contact with the stone and make the damned passes" just doesn't seem to work._

Thanks all for any advice.

Would love to see pictures

 

[Qapla']

The Korin sharpening series includes videos for sharpening yanagiba, deba, and usuba. This might be useful regarding the uraoshi.

https://www.youtube.com/playlist?list=PLsSxXLQSZIe__A5THcrFGto9_PSkXWiN6

Michi.

I'm quite aware of those videos, but I'm not at all a fan of them; none of it explains the purpose of that particular choice of uraoshi or why the hell one would ever use diamond plates for uraoshi a la video #17.

Would love to see pictures

I will take some and post them up. (No, this has nothing to do with any knives from your shop; I just liked your instructional video and use your "marker on the bevel" technique.)

 

[Michi]

I'm quite aware of those videos, but I'm not at all a fan of them; none of it explains the purpose of that particular choice of uraoshi or why the hell one would ever use diamond plates for uraoshi a la video #17.

Ah, I didn't know that. I posted the link in case you hadn't seen them yet.

 

[Qapla']

Ah, I didn't know that. I posted the link in case you hadn't seen them yet.

My fault if that response came a bit hostile; I have in fact badly bungled up a single-bevel knife through ignorant/naive use of diamond-plates (including on the ura). I shouldn't have phrased it that way, sorry.

 

[Qapla']

Would love to see pictures

These two show the usuba; the two black markerspots near the "point" are things I can't seem to get rid of, while the entire area at the rear has been hard to finally abrade evenly with the rest (and there's a streak of marker left near the edge). Basically, this has all been the "raise the shinogi" phase of sharpening; I just can't get the thing to be neutral.

I'll post up the yanagiba after working on it more.

(As mentioned earlier, this isn't about you or any knife of yours, though I'd absolutely welcome your advice.)

 

[Michi]

My fault if that response came a bit hostile; I have in fact badly bungled up a single-bevel knife through ignorant/naive use of diamond-plates (including on the ura).

Sorry to hear that, I understand the distress that would cause.

I shouldn't have phrased it that way, sorry.

Not a problem, we both will recover from the situation!

Keeping my fingers crossed that you'll be able to rectify the bungle!

 

[osakajoe]

or why the hell one would ever use diamond plates for uraoshi a la video #17.

lol. I’m not a fan of a lot of their videos as well for this and other reasons I won’t say on here.

Are you trying to make it entirely flat or a hamaguri? For both Yanagiba and usuba

Some knives have low spots and to avoid removing too much you have to sometimes “lift“ a little to smooth it out. This may be the case with the usuba. But the shinogi still needs to be raised a bit at the tip. Doesn’t look straight in my opinion.

Straightening that out might fix your problem at the tip. If not you may need to lift a little.

 

[never mind]

reasons

Hello osakajoe, thanks for your help on this thread.



I don’t bother people & I trust you more than even many sellers & knife smiths here because many things you said made sense to my brain (reasons vs. blah blah):



Please enlighten me for educational purposes in full (and possible some other folks) what was wrong, what was okay (gray areas in practices either right or wrong) and what was right about the Korin VDOs on youtube? Please?



I respect you and the guy. But I am interested in your opinions, honesty & judgement in this situation for educational purposes (or you can PM me, please).



Just wanted to sharpen knives better than yesterday.



Thank you.

 

[JBroida]

To answer some of your original questions, the amount of how much the shinogi line will need to be raised will depend on how significant the low spots are and if you are trying to get rid of all of them, which is not technically necessary). That being said, it usually isn't that much that the shinogi line gets moved up. In terms of the low spots, the mistake you seem to be making is focusing just on those areas. You actually want to focus on the areas around it as opposed to directly over it, as the issue is that the surrounding areas are taller than that area, and thus the low spot is still visible. Also, hamaguri sharpening helps make this process a lot easier, as it gives you somewhat independent control of the shinogi line and edge.


In looking at the pictures, the tip section seems to be a function of not lifting up quite as much as you might need to. It also looks like you aren't having as much pressure towards the edges you might need to. That is not to say that you need to change the angle so significantly, but rather that you need to apply pressure with your fingers in the correct area to get to these spots that you are missing. Also, keep in mind that you will need to work the areas around them as well.


I also happen to agree with Osakajoe in that the shinogi line seems to drop down a little bit towards the tip.

 

[Cyrilix]

To answer some of your original questions, the amount of how much the shinogi line will need to be raised will depend on how significant the low spots are and if you are trying to get rid of all of them, which is not technically necessary). That being said, it usually isn't that much that the shinogi line gets moved up. In terms of the low spots, the mistake you seem to be making is focusing just on those areas. You actually want to focus on the areas around it as opposed to directly over it, as the issue is that the surrounding areas are taller than that area, and thus the low spot is still visible. Also, hamaguri sharpening helps make this process a lot easier, as it gives you somewhat independent control of the shinogi line and edge.


In looking at the pictures, the tip section seems to be a function of not lifting up quite as much as you might need to. It also looks like you aren't having as much pressure towards the edges you might need to. That is not to say that you need to change the angle so significantly, but rather that you need to apply pressure with your fingers in the correct area to get to these spots that you are missing. Also, keep in mind that you will need to work the areas around them as well.


I also happen to agree with Osakajoe in that the shinogi line seems to drop down a little bit towards the tip.

If you focus on the low spots, won't you automatically focus on the area around it because you won't be able to abrade those low spots and only the area around will come into contact with abrasive?

 

[osakajoe]

...and what was right about the Korin VDOs on youtube?

I’ll only say that I highly disagree with how they sharpen their single bevels. Their take on ura oshi is on steroids imo. It’s good advice to knock a few years off your knife by constantly sharpening the back and always starting with it.

Check out the old guys knife in his yanagiba sharpening video. You see how thick the sharpening line is on the back? That’s textbook over sharpening of the back.

Jon can put into words on the specific of sharpening better than myself and I highly recommend using him and his videos as source.

I’m only good at pointing things out and simple sentences and explanations unless it’s in person and I can show you.

 

[adam92]

To answer some of your original questions, the amount of how much the shinogi line will need to be raised will depend on how significant the low spots are and if you are trying to get rid of all of them, which is not technically necessary). That being said, it usually isn't that much that the shinogi line gets moved up. In terms of the low spots, the mistake you seem to be making is focusing just on those areas. You actually want to focus on the areas around it as opposed to directly over it, as the issue is that the surrounding areas are taller than that area, and thus the low spot is still visible. Also, hamaguri sharpening helps make this process a lot easier, as it gives you somewhat independent control of the shinogi line and edge.


In looking at the pictures, the tip section seems to be a function of not lifting up quite as much as you might need to. It also looks like you aren't having as much pressure towards the edges you might need to. That is not to say that you need to change the angle so significantly, but rather that you need to apply pressure with your fingers in the correct area to get to these spots that you are missing. Also, keep in mind that you will need to work the areas around them as well.


I also happen to agree with Osakajoe in that the shinogi line seems to drop down a little bit towards the tip.

Hi jon, i love all the video you teaching how to sharpen knife on video, very useful and i very appreciate .

Thank you very much, in chinese country usually people don't like to share they knowledge, you're the man !

 

[Qapla']

Are you trying to make it entirely flat or a hamaguri? For both Yanagiba and usuba
...
But the shinogi still needs to be raised a bit at the tip. Doesn’t look straight in my opinion.

Well, the original goal was to do hamaguri sharpening as per Jon Broida's videos. But when seeing that lots of areas had marker-ink left on them, I decided that making the thing straight was a greater priority; that's why I took it to the diamond-plate and ultra-coarse stone. You're definitely right about the point; that failure to effectively target the point-area with the plates has been a pain and is likely a part of the problem.

To answer some of your original questions, the amount of how much the shinogi line will need to be raised will depend on how significant the low spots are and if you are trying to get rid of all of them, which is not technically necessary). That being said, it usually isn't that much that the shinogi line gets moved up. In terms of the low spots, the mistake you seem to be making is focusing just on those areas. You actually want to focus on the areas around it as opposed to directly over it, as the issue is that the surrounding areas are taller than that area, and thus the low spot is still visible. Also, hamaguri sharpening helps make this process a lot easier, as it gives you somewhat independent control of the shinogi line and edge.

In looking at the pictures, the tip section seems to be a function of not lifting up quite as much as you might need to. It also looks like you aren't having as much pressure towards the edges you might need to. That is not to say that you need to change the angle so significantly, but rather that you need to apply pressure with your fingers in the correct area to get to these spots that you are missing. Also, keep in mind that you will need to work the areas around them as well.

I also happen to agree with Osakajoe in that the shinogi line seems to drop down a little bit towards the tip.

Thanks! I am going to work on this. I didn't think of the areas around it; not sure what I was thinking.

I was in fact looking to do hamaguri-style sharpening, but this was all still at the "raise the shinogi" phase as I haven't yet evened things out (as you and Osaka Joe pointed out, the shinogi-raising wasn't entirely even; I've often had it insufficient at the point and risked being excessive at the base, so I've been trying to remedy that). I haven't gotten to the "sharpen the area below the lamination" phase yet, though it'd probably do a lot more direct grinding on the areas near the low-spots.

My current plan is to even out the shinogi line and preferably solve the low spots with the 120-grit stone, and then once it's flattened, clean out the scratches up to 2000-grit and then start the hamaguri'ing with the sharpening of the area below the lamination. Then to use a 6000-grit for both the shinogi-area and below-lamination area, and then do the bevel-fusion. Is this a reasonable plan?

I will post some pictures when I work on it more.

 

[SilverSwarfer]

Well, the original goal was to do hamaguri sharpening as per Jon Broida's videos. But when seeing that lots of areas had marker-ink left on them, I decided that making the thing straight was a greater priority; that's why I took it to the diamond-plate and ultra-coarse stone. You're definitely right about the point; that failure to effectively target the point-area with the plates has been a pain and is likely a part of the problem.



Thanks! I am going to work on this. I didn't think of the areas around it; not sure what I was thinking.

I was in fact looking to do hamaguri-style sharpening, but this was all still at the "raise the shinogi" phase as I haven't yet evened things out (as you and Osaka Joe pointed out, the shinogi-raising wasn't entirely even; I've often had it insufficient at the point and risked being excessive at the base, so I've been trying to remedy that). I haven't gotten to the "sharpen the area below the lamination" phase yet, though it'd probably do a lot more direct grinding on the areas near the low-spots.

My current plan is to even out the shinogi line and preferably solve the low spots with the 120-grit stone, and then once it's flattened, clean out the scratches up to 2000-grit and then start the hamaguri'ing with the sharpening of the area below the lamination. Then to use a 6000-grit for both the shinogi-area and below-lamination area, and then do the bevel-fusion. Is this a reasonable plan?

I will post some pictures when I work on it more.

How’s the sharpening going? I was really interested in the progress, as it mirrors some of my past, present, (future too) projects. The shinogi line raising is particularly important to me. I really pore over preservation of the natural curve and the beauty it reflects. Now I find myself totally and unfairly judging other chefs on their attention or lack of on this often overlooked detail.

 

[Qapla']

How’s the sharpening going? I was really interested in the progress, as it mirrors some of my past, present, (future too) projects. The shinogi line raising is particularly important to me. I really pore over preservation of the natural curve and the beauty it reflects. Now I find myself totally and unfairly judging other chefs on their attention or lack of on this often overlooked detail.

So far I'm still doing battle with the raising the shinogi at the front of the blade; still working on that and the overall flattening process (i.e., that accursed low-spot near the heel of the blade). I ended up having to actively off-angle the knife while focusing on the front of the blade to intentionally "overfocus" on the shinogi area just to compensate (not sure if that's the right thing to do, but hey...). A lot of the rest of it is actually reasonably flat now, but the part near the edge still has those low-spots.

I hadn't been working on it again until recently. It's quite a project even with something as coarse as a Shapton 120. I'll post up pictures in a few days, hopefully I'll have accomplished some more with it.

 

[SilverSwarfer]

I think I’d call it good for now and work out the coarse scratches. You can do a war of attrition on the remaining problem areas.

I have 2 new yanagiba. Both have low spots in the blade road. Both had additional and more significant patches before I did my initial sharpening(s) and started using. Now I just sharpen more frequently and for longer and focus on lessening the remaining spots.

Those couple spots do bug me a little, but they contribute zero to performance- in use, I don’t know they’re there.

Of note: I needed-wanted to start using some new stuff for work. I guess that makes a big impact on the decision to start using or to perfect the aesthetic and performance dynamics. So please consider my comments with that in mind. I definitely understand and respect having a project with specific goals!

 

[Qapla']

Is there any technique for raising the shinogi at the point area? Somehow I'm still having a problem targeting it enough...

So far I've effectively ended up doing a significant amount of shinogi-raising as a result of my flattening efforts, and one of the markered low-spots near the point is finally gone. The other markered-spot at the point and especially the markered-spot (and surrounding low area) at the heel still remain problems.

How’s the sharpening going? I was really interested in the progress, as it mirrors some of my past, present, (future too) projects.

That's pretty cool; what kinds of projects have you got coming up?

I think I’d call it good for now and work out the coarse scratches. You can do a war of attrition on the remaining problem areas.

I have 2 new yanagiba. Both have low spots in the blade road. Both had additional and more significant patches before I did my initial sharpening(s) and started using. Now I just sharpen more frequently and for longer and focus on lessening the remaining spots.

Those couple spots do bug me a little, but they contribute zero to performance- in use, I don’t know they’re there.

Of note: I needed-wanted to start using some new stuff for work. I guess that makes a big impact on the decision to start using or to perfect the aesthetic and performance dynamics. So please consider my comments with that in mind. I definitely understand and respect having a project with specific goals!

So at what level of grit would you recommend attempting hamaguri'ing the bevel?

As far as performance goes, I'll admit it's not that much a factor yet; I'm a home-user and I still can't katsuramuki worth anything. (Nowadays with the usuba still remaining a "project" I try to approximate with a gyuto, but with that I still can only do the "create the initial cylinder" and that's not always all of the time, depending on the [a]symmetry of the initial material and luck [or lack thereof] on my part.)
My goal was to "debug" it permanently and then learn to do normal sharpening on a thereby "properly shaped" knife, but I'm no longer sure if that'll happen. In some ways I'm dreading what will be necessary if I ever do get good enough with this that I'd consider upgrading. (As a collector, part of me wants to add to the collection, but seeing how much of a literal grind this has been so far tends to give me second thoughts.)

 

[SilverSwarfer]

When I’m focused on shinogi raising near the tip, I’m usually a little nervous and always very careful. Generally there’s a curve involved in my cases so it complicates the contact/pressure control. There are several angles of pressure involved which make discussion tedious. There’s downward but also torsional or “twisting” pressure that change depending on the stroke (edge lead/trail). You can feel the shinogi line when you’re working on it and you can adjust “sharpness” with pressure. Also I’m changing the strikes in progressive passes. Initial passes will be more “scrubbing” shorter strokes and finishing passes will be long, flowing strokes. I think of the longer strokes as having blending effects.

I’m really trying to raise the line gradually in every case. That is moving it up incrementally as material is removed from the edge. In cases where I’m trying to adjust the line without removing material I take it slowly. Very slowly. A little bit in each session. In long sessions, fatigue and frustration cause errors. Those errors extend the work.

It looks like you could get good results on the low spots near the edge by raising the spine a little so most of your blade road in not in contact. Then I would work long flowing strokes, some near vertical and some at varying angles, working across the stone and grinding parallel to the edge. This would help blend. I’d check results and then work in scrubbing batches with pressure focusing front-direct-back of each spot. Then blend again.

Katsuramuki with a curved edge is different and I’d try not to practice too much with a curved edge. You’ll develop a feel and your technique will be shaped by your feel. If you get pretty good with the curved edge, you might have to learn new/different technique to be effective with an appropriately straight blade shape.

I’d be fearless of upgrading. You’re doing pretty good and a knife that would be considered an upgrade could likely have no significant issues to correct before “normal” sharpening and use.

I polish way more than what I read most folks on the forum recommend. Therefore I hesitate advising you here. I enjoy 8k edges when I work with synthetics on single bevels. That’s what I’m used to and that’s what works for me. I really really love a JNAT finish. So if it was my knife in my kitchen I’d run a full progression burr based Hamaguri sharpening (focus sharpening on the 1/3 of the blade road near the edge) and then step back to my softer Suita to get an even polish and aesthetically pleasing edge with great performance characteristics. For me. In my kitchen.