# Does my gyuto need thinning?



## oval99 (May 20, 2019)

Well, I’ve just started sharpening my Takamura Migaki on some Shaptons and am happy with my rookie results so far. I’d say it’s been sharpened six times between me and pro sharpeners. However, it occurred to me that when I looked at the choil that perhaps the shoulders looked a little thick and I may need to thin. I still like the cutting performance and it doesn’t wedge too badly (although it is getting harder to split an onion without much effort). 

In others' more expert opinion judging by my pic, should it be thinned? If so, I’ll thin it for my next sharpening session. For comparison, I’ve also included pics of my Takamura Hana gyuto (only been professionally sharpened twice by Dave) and my CCK cleaver, which is super thin. EDIT: Does the right side of the bevel on the Migaki look slightly flatter than the left? Is this a result of my rookie sharpening? If so, why? 

Thanks!


----------



## M1k3 (May 20, 2019)




----------



## McMan (May 20, 2019)

If you're asking, the answer is "yes"


----------



## chinacats (May 20, 2019)

McMan said it best...if you're asking then it likely needs thinning


----------



## oval99 (May 20, 2019)

OK, sometimes it really is that simple! Thanks all.


----------



## lemeneid (May 21, 2019)

The Takamura is already super thin though. Why are you thinning a laser knife?


----------



## refcast (May 21, 2019)

When you start thinning, try doing it from the edge up and make the transitions as smooth as possible for smoothest cut.

Or make a wide bevel with shoulders for more food release, though I don't advise that.

Or start from bottom third or half of the blade and go down. Again, I don't recommend this because most of the effect first lies closes to the edge. Not that you can't do these things, because I have. It's just I like the first option more, and it keeps the overall knife feel more.


----------



## labor of love (May 21, 2019)

Need some better choil shot pics than those to know for sure. Takamura is superthin ootb. Do you have any experience thinning?


----------



## oval99 (May 21, 2019)

Hi Labor of love. I've actually had the Takamura for about 4 years now and it's been sharpened by myself and others about 5 times. I just started sharpening with stones not too long ago and just sharpened the Takamura this weekend on a 1500 Shapton Pro and then finished on a 5K Shapton Pro. I've heard that thinning is just part of a regular sharpening session as any knife, no matter how thin, will start to thicken at the shoulders after it's been sharpened enough. And no, I don't have any experience thinning.

I just noticed that the knife isn't flying through stuff like onions like it once was. There is definitely some resistance when making slices in the onion. By no means is the knife dull (it push-cuts phone book paper), but I'd just like the kind of high-octane performance you see in youtube vids where it looks like they're cutting through air 

But perhaps this is an issue of the edge not being refined enough. Maybe for that kind of performance I'll need to go to an even finer stone (around 8K) and then strop with some micron spray. Or make a more acute angle?

Thanks and I'll try to get a better choil shot.


----------



## lemeneid (May 21, 2019)

If you’ve only sharpened the knife 5 times total, that’s not enough practice to know what sharp is. Before thinning, I suggest practicing sharpening it more. Finer stones won’t do you much good if your technique isn’t right. FWIW, Takamura knives are 3000 grit OOTB, so you clearly need to practice sharpening more.


----------



## oval99 (May 21, 2019)

Thanks lemeneid. Certainly my technique needs improvement. I'm just a little confused by what you mean that I need more practice to "know what sharp is." I must be doing something right if it cuts much better than before, can flow through phone book paper like water, and once nearly stuck into my cutting board. Although I can't feel a burr on either the 1500 stone or the 5K stone I've read on at least one thread that not feeling a burr on finer stones isn't necessarily a bad thing, but it does make me wonder when I should stop on the finer grit stones if I can't feel a burr? Perhaps I wasn't spending enough time on the finer grit stones and eventually I'd raise a burr and then it would be able to glide through something like an onion with almost no resistance.

Later today I'll upload a better choil shot.


----------



## Carl Kotte (May 21, 2019)

lemeneid said:


> If you’ve only sharpened the knife 5 times total, that’s not enough practice to know what sharp is. Before thinning, I suggest practicing sharpening it more. Finer stones won’t do you much good if your technique isn’t right. FWIW, Takamura knives are 3000 grit OOTB, so you clearly need to practice sharpening more.



But wait, look at the first post! It is clearly stated that the knife has been sharpened by a pro too previously. So why would not OP know what sharp is? What do you base that assertion on? (Btw, the number of times one has sharpened a knife oneself is not obviously relevant to one’s capacity to assess sharpness. It is in principle possible to know what sharp is, without knowing how to sharpen).


----------



## Carl Kotte (May 21, 2019)

I have sharpened a friend’s Takamura a few times. I am the first and only person to have sharpened it yet. It is still super thin and slices very well so I have not even considered thinning it yet. But, at some point it will certainly need thinning. Just not there yet.


----------



## M1k3 (May 21, 2019)

I have a Takamura. When I sharpen it, I do some thinning. A few passes at 1k, a few at 6k on each side. Then sharpen as normal. I definitely notice if I skip the thininning. I basically follow the videos I posted but don't do it as extreme.


----------



## oval99 (May 21, 2019)

M1k3 said:


> I have a Takamura. When I sharpen it, I do some thinning. A few passes at 1k, a few at 6k on each side. Then sharpen as normal. I definitely notice if I skip the thininning. I basically follow the videos I posted but don't do it as extreme.


This is helpful, thanks. Perhaps I'll make a few swipes on my 1500 and then on my 5K and then sharpen. Do you find it necessary to thin at a coarse grit (I have a 220) for this thin a knife?


----------



## M1k3 (May 21, 2019)

oval99 said:


> This is helpful, thanks. Perhaps I'll make a few swipes on my 1500 and then on my 5K and then sharpen. Do you find it necessary to thin at a coarse grit (I have a 220) for this thin a knife?



I don't find coarse grit necessary. I'm only trying to remove as much metal thinning as is removed from the edge sharpening. "Maintenance thinning" I guess it could be called? Just keeping the "shoulders" away.

P.S. Your knife will probably not look as flashy after this. I just deal with it. But I also work in a restaurant full time so for me, Performance > Aesthetics.


----------



## chinacats (May 21, 2019)

Tendency is for new sharpeners to dull the knife w a finishing stone. I would also suggest that your knife should "glide through on onion like butter" just as equally after a clean 1k finish. 

Cutting paper doesn't tell you much. 

If you're reaching the apex with your final stone then you're creating a burr even if you can't feel it.


----------



## krx927 (May 21, 2019)

In my experience the knife definitely needs thinning after 5 sharpenings (even sooner), even if we are talking about ultimate laser like Takamura. Even you are saying that you can see the shoulders.

About your other question why the right side on the pics looks flatter (this is actually left side when you hold the knife), this is normal grind for Japanese knives. The right side is always more convex to help with food release on the right handed knives. Nothing to do with your sharpening.


----------



## Nemo (May 21, 2019)

Carl Kotte said:


> But wait, look at the first post! It is clearly stated that the knife has been sharpened by a pro too previously. So why would not OP know what sharp is? What do you base that assertion on? (Btw, the number of times one has sharpened a knife oneself is not obviously relevant to one’s capacity to assess sharpness. It is in principle possible to know what sharp is, without knowing how to sharpen).


It depends on who the "pro" was and how they sharpened the knife.

Whilst it is true that on a theoretical level, the ability to assess sharpness is distinct from the ability to make a knife sharp, the two skills both tend to be improved by practice sharpening and thinking and learning about sharpening.


----------



## Nemo (May 21, 2019)

M1k3 said:


> I have a Takamura. When I sharpen it, I do some thinning. A few passes at 1k, a few at 6k on each side. Then sharpen as normal. I definitely notice if I skip the thininning. I basically follow the videos I posted but don't do it as extreme.


I also tend to do a little thinning on a medium stone every time I sharpen on a medium stone. Reduces the need for a massive thinning job later on. I don't usually bother if it's just a touch up on a fine stone.


----------



## M1k3 (May 21, 2019)

Nemo said:


> I also tend to do a little thinning on a medium stone every time I sharpen on a medium stone. Reduces the need for a massive thinning job later on. I don't usually bother if it's just a touch up on a fine stone.



Definitely if it's a touch-up/stropping, no need to thin. Otherwise I hit the sides.


----------



## lemeneid (May 21, 2019)

oval99 said:


> Thanks lemeneid. Certainly my technique needs improvement. I'm just a little confused by what you mean that I need more practice to "know what sharp is." I must be doing something right if it cuts much better than before, can flow through phone book paper like water, and once nearly stuck into my cutting board. Although I can't feel a burr on either the 1500 stone or the 5K stone I've read on at least one thread that not feeling a burr on finer stones isn't necessarily a bad thing, but it does make me wonder when I should stop on the finer grit stones if I can't feel a burr? Perhaps I wasn't spending enough time on the finer grit stones and eventually I'd raise a burr and then it would be able to glide through something like an onion with almost no resistance.
> 
> Later today I'll upload a better choil shot.


I get a nice big juicy burr even on my super fine Narutaki stone. If your edge is thin enough, you will get a burr no matter what.

Also don’t look at paper cutting as a good test, cut some tomatoes and onions instead, that should tell you how good the knife cuts.


----------



## M1k3 (May 21, 2019)

lemeneid said:


> I get a nice big juicy burr even on my super fine Narutaki stone. If your edge is thin enough, you will get a burr no matter what.
> 
> Also don’t look at paper cutting as a good test, cut some tomatoes and onions instead, that should tell you how good the knife cuts.



Lemons and eggplant also.


----------



## Jville (May 21, 2019)

It sounds like you need to thin the knife. You can really feel a knifes grind on onions. That knife shouldnt struggle with onions.


----------



## oval99 (May 22, 2019)

Wow, a lot of great advice here. After looking at all the comments, I think my best course of action is to moderately thin the knife using a 1500 stone and then sharpen it again on the 1500 and finish on the 5K, hopefully raising a tactile burr. If I can't feel the burr, I have a 30x loupe that may help.

I've posted a better choil shot here and would love to know if people think the knife needs to be thinned...


----------



## labor of love (May 22, 2019)

M1k3 said:


> I have a Takamura. When I sharpen it, I do some thinning. A few passes at 1k, a few at 6k on each side. Then sharpen as normal. I definitely notice if I skip the thininning. I basically follow the videos I posted but don't do it as extreme.


I’ll take this advice as well.
Thanks


----------



## labor of love (May 22, 2019)

oval99 said:


> Wow, a lot of great advice here. After looking at all the comments, I think my best course of action is to moderately thin the knife using a 1500 stone and then sharpen it again on the 1500 and finish on the 5K, hopefully raising a tactile burr. If I can't feel the burr, I have a 30x loupe that may help.
> 
> I've posted a better choil shot here and would love to know if people think the knife needs to be thinned...
> 
> View attachment 53537


Definitely needs thinning.


----------



## Carl Kotte (May 22, 2019)

Nemo said:


> It depends on who the "pro" was and how they sharpened the knife.


True - and obvious, right?! But, if OP tested the Takamura ootb he had some relevant idea of sharpness to assess the quality of a pro’s work (from my experience they are delivered sharp enough, and quite consistently though discrepancies occurr). So my point still stands - noise notwithstanding.


----------



## oval99 (May 22, 2019)

Carl Kotte said:


> True - and obvious, right?! But, if OP tested the Takamura ootb he had some relevant idea of sharpness to assess the quality of a pro’s work (from my experience they are delivered sharp enough, and quite consistently though discrepancies occurr). So my point still stands - noise notwithstanding.


Yep, agreed. I definitely remember when I got it out of the box. It kept sticking to the board. That’s when I realized what sharp truly was. And it just shot through onions/tomatoes/whatever like they weren’t there. Also remember when I got it back from Dave — same Ferrari performance.

Putting everything together (both from this thread and my new sharpening experience) I really do think it needs thinning. The knife certainly isn’t “dull” (barely have to use more than the weight of the knife for celery, scallions, and even tomatoes slice pretty well) but stuff like carrots and onions feel like I need to push through more than I used to.

So off to thinning I go!


----------



## Carl Kotte (May 22, 2019)

oval99 said:


> Yep, agreed. I definitely remember when I got it out of the box. It kept sticking to the board. That’s when I realized what sharp truly was. And it just shot through onions/tomatoes/whatever like they weren’t there. Also remember when I got it back from Dave — same Ferrari performance.
> 
> Putting everything together (both from this thread and my new sharpening experience) I really do think it needs thinning. The knife certainly isn’t “dull” (barely have to use more than the weight of the knife for celery, scallions, and even tomatoes slice pretty well) but stuff like carrots and onions feel like I need to push through more than I used to.
> 
> So off to thinning I go!



Very wise!


----------



## Carl Kotte (May 22, 2019)

Carl Kotte said:


> Very wise!



And good luck! Come back with a report on the result!


----------



## Jville (May 22, 2019)

I suspect it will be back to blazing through onions.


----------



## M1k3 (May 22, 2019)

I just remembered another tip! Use a sharpie on the blade face. It'll show where the high and low spots are as you're thinning. Be warned, you may get sad at how uneven it is.


----------



## oval99 (May 22, 2019)

OK, so things are heading in the wrong direction  I spent about an hour on my coarse 220 Shapton stone thinning the bottom 1/3 of the blade. I marked with a sharpie the bottom third and checked to see if I was removing it. I was. But instead of things getting better, they got progressively worse. Now the knife REALLY wedges in onions, way worse than before. Two choil shots below: one on the top is new, bottom one is the previous shot before thinning.

I have three theories about why this is happening:

1) I've applied unequal pressure when thinning, and some parts of the knife are thinner than others
2) I've concentrated too much near the edge of the knife and not further up towards the "shoulders" --* judging by my new pic, I think this is the culprit. The old pic (one on the bottom) has a profile that is more "straight" (like a razor blade) whereas my new pic seems to bulge out (get "shoulders") much earlier from the edge. Perhaps I need to work exclusively on the area further away from the edge (about 1/2" or so).*
3) The blade is becoming dull from all the thinning (unlikely)

Anyone know what's going on?


----------



## M1k3 (May 22, 2019)

You need to get roughly 2/3rds of the way up.


----------



## oval99 (May 22, 2019)

Wow, that will take a long long time! Thanks for the tip though


----------



## refcast (May 22, 2019)

Try polishing the surface a bit with sandpaper, metal polish, or bar keeper's friend. Often after going really coarse, I find the surface left over is really grippy to food and causes wedging not due to geometry, but due to surface finish. Like splitting a log with an thin axe covered in sandpaper vs a thick axe that has a smooth finish. 

Your point (2) does have some merit. I do get better food release and splitting of food with shoulders. So it sticks less that way. Both ways are valid and up to preference or situation (thinning close to the edge vs higher up the blade).


----------



## Nemo (May 22, 2019)

oval99 said:


> Also remember when I got it back from Dave — same Ferrari performance.


Are we talking Dave Martell? If so, that's certainly a good benchmark.


----------



## lemeneid (May 22, 2019)

This is why I never recommend novices do any thinning. Why on earth would you need to thin a laser anyway? Takamura, Shibata, Ginga, etc are all thin enough they don’t wedge and naturally thin if you sharpen correctly with good technique and angles.

To OP, you can’t judge the knife’s geometry from a choil shot. All it does is show how the knife looks at the heel.

Unless you’re ok with making this a project knife with the possibility of making things worse, I suggest taking it back to Dave Martell and getting him to fix up the knife for you. It will cost you but at least you don’t do anything irreversible. He can at least look at it and tell you professionally what happened because there is only so much pictures can tell how the grind has changed.

Otherwise if you’re making this your project knife, thin away!


----------



## Jville (May 23, 2019)

After you thinned on a 220 did you sharpen it?


----------



## lemeneid (May 23, 2019)

IMO you’ve probably created a thick secondary bevel on the edge which is why the knife isn’t cutting well and that needs to be fixed with very aggressive angles or even laying the blade flat on an equally flat stone. You will probably screw up the finish on the knife doing this but that would be my way forward with the little information I have. Which is why I recommend getting a professional fix this for you because there is no way of knowing what’s wrong without working the knife personally.


----------



## labor of love (May 23, 2019)

gingas, tads, takamuras indeed start to suck if they’re sharpened over and over again and never thinned. But these are some of the easiest knives to thin IMO. A little can go a long way. It is suspect that this knife is performing poorly after only six sharpenings but the choil shot for an ootb takamura should be a lot thinner than what you demonstrated in the photo. 
I’m not sure anyone had ever thinned a knife really well the first time. Keep studying, watch thinning videos and practicing. Can you take photos of your thinning scratches?


----------



## lemeneid (May 23, 2019)

labor of love said:


> gingas, tads, takamuras indeed start to suck if they’re sharpened over and over again and never thinned. But these are some of the easiest knives to thin IMO. A little can go a long way. It is suspect that this knife is performing poorly after only six sharpenings but the choil shot for an ootb takamura should be a lot thinner than what you demonstrated in the photo.
> I’m not sure anyone had ever thinned a knife really well the first time. Keep studying, watch thinning videos and practicing. Can you take photos of your thinning scratches?


You’re definitely right with that, that’s why I found it baffling thinning was started on a really aggressive 220 stone. If anything, and the wrong angles, you probably ended up with too thick an edge too quickly. Should have started on the 1500 like some others recommended.


----------



## Knife2meatu (May 23, 2019)

oval99 said:


> OK, so things are heading in the wrong direction  I spent about an hour on my coarse 220 [...] But instead of things getting better, they got progressively worse. Now the knife REALLY wedges in onions, way worse than before.[...]
> 
> I have three theories about why this is happening
> [...]
> ...



I'm nowhere near knowledgeable on any of this -- but perhaps this advice is best given by an admittedly rank amateur: If I'm correct in the assumption that you're doing all this thinning with the edge still sharp and intact, I would suggest you consider perhaps instead dulling it beforehand next time.

I've found that the force involved in thinning, a moment of unforeseen stiction, fingertips, and a really sharp edge, can make for a painfully memorable mix.


----------



## oval99 (May 23, 2019)

All,

I have some results to report. They're pretty anticlimactic, really. After a long session on an Atoma 120 diamond plate, nothing really seemed to happen (other than taking off a metric ton of steel, of course). Profile didn't change much, and performance perhaps improved a tad, but it still wedges badly on onions. And yet it still cuts incredibly well for just about everything else I prep (tomatoes, scallions, bell peppers). Also didn't wedge TOO badly in carrots. 

And yes, I've dubbed this my test/project knife. The scratch patterns don't bother me -- it doesn't need to hang in the Louvre. If all else fails, I'll send it to Dave and see if he can fix it when funds allow.

Below are some pics of the scratch patterns:


----------



## labor of love (May 23, 2019)

Well I’m glad to know you have a contingency plan.
With your diamond plate you thinned quite a bit up the blade. What happens here is that your focusing your pressure on a broader area instead of a small area, the impact felt from thinning won’t be as effective. If you just put pressure on a smaller area you should feel the results sooner. Your finger tip placement decides the pressure as long as you’re laying the blade flat on the stone. Shorter thinning strokes (like 3 inches forward and back) guarantees better repeat/hitting the same spot over and over again and removing metal from the area as opposed to going all the way from the bottom of the stone face to the top(really long 8 inch strokes).
If you want to feel progress sooner and I’d focus my pressure closer to the edge, use shorter strokes, focus on repeating the same spot over and over again as I work my hands down the blade.
Nothing I’m saying here is written in stone as law. But it does work well for me.


----------



## labor of love (May 23, 2019)

Did everything I say make sense? Let’s have so more discourse before your next thinning session.


----------



## TurboScooter (May 23, 2019)

refcast said:


> Try polishing the surface a bit with sandpaper, metal polish, or bar keeper's friend. Often after going really coarse, I find the surface left over is really grippy to food and causes wedging not due to geometry, but due to surface finish. Like splitting a log with an thin axe covered in sandpaper vs a thick axe that has a smooth finish.
> 
> Your point (2) does have some merit. I do get better food release and splitting of food with shoulders. So it sticks less that way. Both ways are valid and up to preference or situation (thinning close to the edge vs higher up the blade).



IME this is absolutely a valid consideration.

It's tedious as fvck if you end up wanting to go further in your thinning job, but I basically refinished my blade to test if I was happy with my thinning job. With the finish left by a coarse stone it drags badly and you can't really tell what the performance will be like once you refinish the blade.


----------



## labor of love (May 23, 2019)

Yeah, this is true. I Atleast finish my thinning with a chosera 400 or a 1k or micro mesh pad polish before I test how it cuts.


----------



## labor of love (May 23, 2019)

Also, there’s nothing really wrong with thinning that high up the blade if you want to(with the atoma) but results will take longer.


----------



## McMan (May 23, 2019)

labor of love said:


> Well I’m glad to know you have a contingency plan.
> With your diamond plate you thinned quite a bit up the blade. What happens here is that your focusing your pressure on a broader area instead of a small area, the impact felt from thinning won’t be as effective. If you just put pressure on a smaller area you should feel the results sooner. Your finger tip placement decides the pressure as long as you’re laying the blade flat on the stone. Shorter thinning strokes (like 3 inches forward and back) guarantees better repeat/hitting the same spot over and over again and removing metal from the area as opposed to going all the way from the bottom of the stone face to the top(really long 8 inch strokes).
> If you want to feel progress sooner and I’d focus my pressure closer to the edge, use shorter strokes, focus on repeating the same spot over and over again as I work my hands down the blade.
> Nothing I’m saying here is written in stone as law. But it does work well for me.


I agree with Labor.
You can the importance of finger pressure/location at 2:20.
I should've posted this earlier... better late than never.


----------



## labor of love (May 23, 2019)

I’ve always loved that handle on Jon’s Zakuri!


----------



## krx927 (May 23, 2019)

In my opinion you now need to do 2 things to really evaluate your thinning result:

1. you need to refinish the knife a little bit (or fully) and get rid of the thinning scratches. There are many threads on KKF about this. If you need some help we can give you further pointers.
2. You will need to resharpen your knife. In my experience you always loose the sharpness when thinning even if you think you are not touching the cutting edge.


----------



## M1k3 (May 23, 2019)

Hopefully the photo shows how high I go. It's nearly flat where it doesn't look pretty and convexes (hamaguri) at/near the edge.


----------



## Jville (May 23, 2019)

Could you also show another choil shot, because youve thinned more since your last pic?


----------



## M1k3 (May 23, 2019)

Jville said:


> Could you also show another choil shot, because youve thinned more since your last pic?



Me? I'm not OP but I'll attach pictures of it


----------



## Jville (May 23, 2019)

M1k3 said:


> Me? I'm not OP but I'll attach pictures of it


I thought these were before he finished thinning, tweener pics.


----------



## oval99 (May 23, 2019)

The avalanche of advice is frankly amazing! I’m blushing, truly. I particularly appreciated labor of love's, well, labor of love in his in-depth responses.

But I also know when I’m in over my head; I feel like I have bees buzzing in my head from all the info. I think lemeneid has the right idea: when my funds allow, I’ll send it to Dave Martell and see what he can do to repair it. More importantly, I’d love to know WHAT he did to it and where I went wrong. Otherwise I know I’ll find myself in a quicksand.

This is what is so insidious about learning this stuff over the net: it only takes me so far. I tend to learn by having a decent framework of the concept (YouTube vids and this forum help here), then doing the task, making mistakes, and then having an expert in person show me where I went wrong. THEN the concept really sinks in; then I am truly learning from my mistakes —from my _experience_. 

You ever had to read/watch training material for a new skill, take and pass the test but the concept is still foggy, then struggle on your own and make mistakes by directly using the skill/product, and THEN go back to the training materials? For me, that’s when I truly read/understand the training materials — once I have the fumbling/infuriating/exhilarating first-hand experience of wrestling with the damn thing, then I truly understand the concepts. Perhaps I could talk with Dave after he’s sharpened/repaired my knife about what he did (and what I DID) so it can really sink in first-hand.


----------

