thinning questions (yet another thread)

[noj]

I'd like to learn more about this, but I feel stuck.

The only one of the knives mentioned above (ones I thinned) I am willing to do more with is maybe the nakiri. I feel stuck on that because I am not sure there is enough metal left, plus not knowing if I am correcting issues B and C while working on issue D. I suspect I created issue D (low region in the soft steel just above the cladding line) while thinning. Right now the blade is dead flat (other than the low region) until somewhere in the last few mm, and it's about 0.6 mm thick at 5 mm behind the edge. The nakiri is also stainless clad, so I wasn't planning any fancy polishing results; just practice. Most of the thinning was done before I joined the forum, based on some (not so good recommendation) from a store.

Willing to try a different blade, but don't own one I am willing to experiment on, except for normal sharpening and performance.

Whether it's a new blade, or existing one, I am not willing to sacrifice much kitchen performance for polishing. If that means only polishing a wide bevel (people keep saying you have to flatten), then I would like to know. If it always makes kitchen performance much worse, maybe I will find another hobby.

 

[noj]

Bump.

If my questions are too whatever to answer, let me know what whatever is, and I will un-whatever them.

Willing to try a different knife with a defined bevel. Willing to put in the time if I can get feedback if I run into issues.

 

[NickMinton]

Hey NoJ,

Not sure if this is helpful but I learned a lot by sharpening other peoples knives that were badly taken care off

These were a lot of cheap deli style knives that had broken tips, chips in the blade or several previous episodes of terrible sharpening that resulted in multiple uneven bevels.

Because of this, I got a lot of experience in having to reshape, thin out, Rebevel and then resharpen these knives.

For a lot of these knives, I could only put a proper bevel on them originally if I was at 30+ degrees of height because of how thick they were.

The big savior to all of this was thinning on an Atoma 140 diamond plate, then thinning on an Atoma 400 plate while reprofiling the bevels on the Atoma 400 as well.

After all the thinning, my angle could then be at 20-25 degrees to sharpen and get an even, consistent burr.

Prior to this, I had always used pretty nice, thin Japanese knives that didn’t need a ton of thinning, so it was hard to quickly see whether my thinning made much of a difference.

Only once I started with really thick, cheap knives did I fully see what I was doing and how much of a difference it made

 

[noj]

Hey NoJ,

Not sure if this is helpful but I learned a lot by sharpening other peoples knives that were badly taken care off

These were a lot of cheap deli style knives that had broken tips, chips in the blade or several previous episodes of terrible sharpening that resulted in multiple uneven bevels.

Because of this, I got a lot of experience in having to reshape, thin out, Rebevel and then resharpen these knives.

For a lot of these knives, I could only put a proper bevel on them originally if I was at 30+ degrees of height because of how thick they were.

The big savior to all of this was thinning on an Atoma 140 diamond plate, then thinning on an Atoma 400 plate while reprofiling the bevels on the Atoma 400 as well.

After all the thinning, my angle could then be at 20-25 degrees to sharpen and get an even, consistent burr.

Prior to this, I had always used pretty nice, thin Japanese knives that didn’t need a ton of thinning, so it was hard to quickly see whether my thinning made much of a difference.

Only once I started with really thick, cheap knives did I fully see what I was doing and how much of a difference it made

I probably have 120+ hours in on these ..

1. 40 year old nakiri (thin, inexpensive)
fixed frown, as much clean up as I could do on such a thin knife
not used much any more
2. 40+ year old Sabatier chef's and petty knives
fixed all sorts of abuse: frown, badly rounded tip, thick behind edge, and low spots going to edge
the steel is so soft, it doesn't hold up without a 25 degree (per side) edge
much improved
3. H. Togashi Nakiri (discussed in this thread)
not sure what if anything to do with it, other than just use/sharpen until it gets thicker behind edge
4. mukimono (in a different thread)
don't want to deal with this right now
5. Forgecraft chef's knife (discussed in this thread)
still has a very slight low spot going to edge, but not sure if it's worth loosing more metal/height to remove it.
much improved
6. fixed cheap stainless thin and flexible petty-type knife
7. started thinning a very thick and uneven cheap stainless Sabatier knock-off
took forever to remove significant metal, even with Atoma 140, and the multitude of deep low spots going to the edge were not inspiring

I don't like working on stainless, the steel feels very gummy. Maybe I should get over it? That's one reason I worked on the Forgecraft. I worry picking up junkers at some charity place will get me back into something like my Sabatier knock-off.

 

[noj]

Bump.

Guess this thread died.

Maybe if I break up each question and/or knife into it's own thread?

Maybe people blocked me, and/or don't read my posts?

 

[Rangen]

Bump.

Guess this thread died.

Maybe if I break up each question and/or knife into it's own thread?

Maybe people blocked me, and/or don't read my posts?

The last is extremely unlikely.

I went over the last few pages, and my best guess about why you are not getting many responses is: no one can tell what unanswered questions you have. I couldn't. I couldn't even manage a guess about what you want answered at this point.

If you make a post that is as clear as this one you just made, that asks your unanswered questions, just one sentence for each, I'd bet you'll get some answers to those questions.

 

[Heckel7302]

I find it difficult to put things into words, especially without seeing the problem in person. Best advice I can give is don't give up. I've learned more from practice, playing around with different things until something works.

For the nakiri with the low spot, I don't think you can really go too far, except close to the edge. Work from the shinogi down. Try to create a hamaguri bevel, isolating the cladding and core steel, then blending at the end.

 

[ian]

The last is extremely unlikely.

I went over the last few pages, and my best guess about why you are not getting many responses is: no one can tell what unanswered questions you have. I couldn't. I couldn't even manage a guess about what you want answered at this point.

If you make a post that is as clear as this one you just made, that asks your unanswered questions, just one sentence for each, I'd bet you'll get some answers to those questions.

Yea, you need to ask more direct and specific questions, @noj. As is, you’re just describing your experience and saying “make me a better sharpener”.

 

[noj]

First, thanks for the feedback; I will improve my style. Just to repeat, I am interested in practice grinding knives for better pre-polishing or polishing.

Which, if any, of the knives I mentioned are worth working on?

My guess is just the Togashi Nakiri (also based on @Heckel7302 reply), and the fact that I don't want to deal with the single bevel. If narrowed down to one knife, questions are a lot easier to formulate.

 

[Heckel7302]

First, thanks for the feedback; I will improve my style. Just to repeat, I am interested in practice grinding knives for better pre-polishing or polishing.

Which, if any, of the knives I mentioned are worth working on?

My guess is just the Togashi Nakiri (also based on @Heckel7302 reply), and the fact that I don't want to deal with the single bevel. If narrowed down to one knife, questions are a lot easier to formulate.

If polishing is the goal, then definitely something clad with a distinct shinogi is your best bet. Full convex is another level up in skill, one I don't feel comfortable with yet. Iron clad certainly more forgiving than stainless clad. The vintage monos like forgie and sab I would say are fine for practicing geometry, but I always finish those with sandpaper to make them look nice.

 

[noj]

Based on the comments, I'd like to discuss the Togashi Nakiri. I did get a thickness measurement. It's about 0.5 mm at 5 mm behind the edge, so I don't think I should take it measurably thinner. I assume that means raising the shinogi, but I don't want to make it look or cut badly.

My question on the topic of the Togashi Nakiri:
Is there is something left to learn on this specific knife in terms of better pre-polishing?

If not, I am ok with getting a practice knife.

The one photo I posted here gives some idea, and you can see the hamaguri bevel:
https://www.kitchenknifeforums.com/threads/thinning-questions-yet-another-thread.62237/post-988402
There appear to be high spots (polished vs rough) along the shinogi, and core steel, and course scratches just above the cladding line in the stainless. Either it was originally slightly concave, or I did it. If the latter, I would like to learn how to stop it. I am usually pretty good about keeping the course stones flat and clean.

If pictures would help, I can post some as-is, or magic marker and then some light grinding on a 1k stone.

Alternatively, I could burnish (maybe without the magic marker mess) to show you the high spots.

 

[noj]

Based on the comments, I'd like to discuss the Togashi Nakiri. I did get a thickness measurement. It's about 0.5 mm at 5 mm behind the edge, so I don't think I should take it measurably thinner. I assume that means raising the shinogi, but I don't want to make it look or cut badly.

My question on the topic of the Togashi Nakiri:
Is there is something left to learn on this specific knife in terms of better pre-polishing?

If not, I am ok with getting a practice knife.

The one photo I posted here gives some idea, and you can see the hamaguri bevel:
https://www.kitchenknifeforums.com/threads/thinning-questions-yet-another-thread.62237/post-988402
There appear to be high spots (polished vs rough) along the shinogi, and core steel, and course scratches just above the cladding line in the stainless. Either it was originally slightly concave, or I did it. If the latter, I would like to learn how to stop it. I am usually pretty good about keeping the course stones flat and clean.

If pictures would help, I can post some as-is, or magic marker and then some light grinding on a 1k stone.

Alternatively, I could burnish (maybe without the magic marker mess) to show you the high spots.

Since no answer ..

As it turns out, and concavity or low spots were much less than the thickness of magic marker ink (plus the stuff gums up my stones).

One oddity was a spot roughly mid blade where the shinogi dips toward the edge, which made me guess it was a low spot. However, on the stones, the bevel below it burnished bright with dark scratches on both sides, indicating a high spot. I spent some time grinding it lower, plus blending things together, and the surface looks pretty uniform now, albeit rough (Shapton ceramic 1000).

Being soft stainless cladding, is there anything worth doing next, even if it's just practice? The hard steel could be polished more, but as far as I know, stainless just gets dark grey with finer grits.

Excuse the lack of pretty, this is a well used kitchen knife.

Good, bad, try this or that?

 

[noj]

is there anything worth doing next?

 

[Jovidah]

Rounding the choil?

 

[noj]

Rounding the choil?

Thanks, I will consider that later perhaps. It's hard to see, but the choil finish is quite polished, but the shape is perhaps odd. In fact, the shape triangular with the slightly rounded point to rest your finger against;-)

I was mainly interested in learning more about pre-polish and polish right now. I just don't know what, if anything, is worthwhile with soft stainless.

 

[ethompson]

You can make stainless cladding into a nice kasumi, in fact it'll often have a lot of grain and character if that's your type of dragon to chase. It's just not usually a pleasant experience to get there. My usual process for stainless cladding is to try every stone I have on it and then when none of them work try the first one I used which somehow magically decides to work on second approach. Joking aside, a lot of forced slurry will help keep things even and overcome some of the gummy-ness that often happens with stainless.

My other suggestion here would be to use tape and sand paper to create a nice hairline finish and the impression of a crisp linear shinogi. The original finish was probably done with a media blaster and stencil, so this approximates that. Take it up to 2k or so with very linear strokes and then finish with a bunch of stone powder or soft finger stone to bring back some contrast.

Not needed at all though.

 

[tostadas]

Kasumi is doable on stainless. Here are my takamura r2 and kaeru ss.

 

[noj]

Kasumi is doable on stainless. Here are my takamura r2 and kaeru ss.

Nice, thanks for the pics/movie.

After your ~1000 range of stone, what did you use?

In the next grit range, I have Naniwa Chosera 3000 and Naniwa SS 3000, and both turn the steel dark. I have a JNS red Aoto also. Maybe cleaning up with sandpaper or metal cleaner when done?

 

[tostadas]

Nice, thanks for the pics/movie.

After your ~1000 range of stone, what did you use?

In the next grit range, I have Naniwa Chosera 3000 and Naniwa SS 3000, and both turn the steel dark. I have a JNS red Aoto also. Maybe cleaning up with sandpaper or metal cleaner when done?

For the core, I usually go full synthetics up to 6k. Then for cladding I start with king 800 and then go to naturals. If you want a kasumi, don't follow it with sandpaper or else it will basically remove your work. Sandpaper does a decent job at clean finishes, but you will not get any hazy look from it.

 

[noj]

For the core, I usually go full synthetics up to 6k. Then for cladding I start with king 800 and then go to naturals. If you want a kasumi, don't follow it with sandpaper or else it will basically remove your work. Sandpaper does a decent job at clean finishes, but you will not get any hazy look from it.

I tried an Aizu on the cladding. With no slurry, I started getting interesting, but very fine detail, but the metal is grabby. I tried slurry, and it was much easier to move over the stone, but the detail went poof;-) More specifically, it got dark. I'll try some other things as I have time.

 

[noj]

Slurry from other/finer stones reacted better.

There's a very fine detail in the stainless I can't capture with my camera. The entire surface is covered with tiny rectangular/rhombus patterns.

I still see what I guess are small low spots, because they don't polish. I hid some of it with a finger-stone. There's a long streak parallel and just below the shinogi. I am not sure what it's origin is; perhaps a bit of a high spot?

Any suggestions or comments welcome.

If I have to phrase as a question: what's right or wrong with what I did?

I'll work the other side next.

 

[noj]

Aha, posting a related thread in case it helps others (or myself).

Thinning...?

 

[milangravier]

Slurry from other/finer stones reacted better.

There's a very fine detail in the stainless I can't capture with my camera. The entire surface is covered with tiny rectangular/rhombus patterns.

I still see what I guess are small low spots, because they don't polish. I hid some of it with a finger-stone. There's a long streak parallel and just below the shinogi. I am not sure what it's origin is; perhaps a bit of a high spot?

Any suggestions or comments welcome.

If I have to phrase as a question: what's right or wrong with what I did?

I'll work the other side next.
View attachment 248946

My opinion : That "long streak parallel and just bellow the shinogi" is the "natural" shinogi where the blade wanted it to be set, the few mm above would be some overgrind.
When you shape the bevels of your knife, longitudinally, things are pretty align along the edge (if not you could have a hollow blade profile for exemple), but along shinogi it is not really easy to feel where it should be set in order this shinogi is one plain line without waves (within the thickness, not the shinogi shape). Looks like the blade would have prefer a lower shinogi in the middle on the blade so it would have been one line from heel to "tip"

 

[noj]

My opinion : That "long streak parallel and just bellow the shinogi" is the "natural" shinogi where the blade wanted it to be set, the few mm above would be some overgrind.
When you shape the bevels of your knife, longitudinally, things are pretty align along the edge (if not you could have a hollow blade profile for exemple), but along shinogi it is not really easy to feel where it should be set in order this shinogi is one plain line without waves (within the thickness, not the shinogi shape). Looks like the blade would have prefer a lower shinogi in the middle on the blade so it would have been one line from heel to "tip"

Thanks for the expert feedback!

This particular knife had a long history, and as some have pointed out, perhaps not the best type to try and polish.

It all started when I tried to thin and sharpen (as well as I understood at the time). There were high/low spots all over the wide bevel. I tried to grind them away, but used way too fine a stone, and (correct me if in error) ground way too much at the shinogi vs hard steel. I have tried to make it a little better since then, but can't put metal back (except in my imagination).

That streak doesn't show up (or I can't see it) any more. I also included a photo with a reflection of a window screen to look for flatness, if that's of interest. Although hard to photograph (so didn't), if I get a reflection of a straight line above the shinogi, it's quite full of ripples, especially near the curves in the shinogi.

Obviously, I did some more work on it. Finer stones to polish, and a relief bevel which isn't blended in.

 

[noj]

Aha #2, posting a related thread in case it helps others (or myself).
https://www.kitchenknifeforums.com/threads/hand-position-for-thinning.69342/