What to expect from my Kaeru stainless gyuto?

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kryft

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Hi! A couple of weeks ago I started thinking that I should finally figure out how to sharpen my old Wüsthof, which had only ever seen a diamond-coated steel that I bought with the knife 10 years ago. I tumbled down the rabbit hole rather quickly, and last Tuesday I received my 210 mm Kaeru Kasumi Stainless Gyuto and a Naniwa Pro 800 stone.

Unfortunately I had a bit of a rough start: for some reason the Kaeru wasn't very sharp out of the box (couldn't really cut paper well, edge didn't really feel sharp to my fingers), so I immediately had to start learning how to sharpen it. I've been following the common advice of learning how to do everything (burr forming, deburring, stropping) on a medium grit stone before getting other tools. A few hours of practice later I managed to make it much sharper than it was when I got it, but there's probably still a lot of room for improvement. After my last sharpening session I could cut paper fairly well, although the area near the tip was a bit duller than the rest of the edge. I decided to try it on some actual vegetables that I was chopping for a stir fry.

The first thing I tried to cut was a medium-sized onion, and while it was perfectly doable, the knife didn't really feel sharper than the old Wüsthof. (I tried both knives. Although the Wüsthof is a bit sharper now than it used to be, because I sharpened it on the stone as my first attempt at sharpening, and although it didn't come out shaving sharp, it was still sharper than it had ever been.) The vertical cuts that I made with the tip particularly felt like they required a decent amount of force and it felt like some of the intermediate layers wobbled a little when the knife didn't just cleanly bite into them. Bell peppers and spring onions were fine, and maybe the Kaeru was better here. Garlic clove root ends and ginger offered some resistance. My cutting technique is probably not the best, although I used the same mediocre technique with both knives (pinch grip, push cuts or draw cuts).

Incidentally it's possible that my cutting board dulls the edge rather quickly; it's a composite board by Arcos that I sadly bought just before I decided to become a knife nut. But the onion was the first thing I cut (apart from some paper and the odd arm hair) after sharpening, so unless touching the board a couple of times was enough to kill the edge, the board probably isn't to blame here. :) (Feel free to advise me on this if you know how bad the board is - I'd rather not buy another one if this one isn't a disaster, but I can get a better board if I need to.) The edge did feel duller after prepping than it did before that, although it could still cut print paper somewhat well. I guess it's also possible that I had a little wire edge or burr after sharpening?

One issue I have is that I've never had a really sharp knife before, gyuto or otherwise, so I don't know what cutting an onion (or anything else) is supposed to feel like. I know several people on this forum own or have owned a Kaeru and like it, so I was wondering if you could give me a realistic idea of what I can expect from this knife once it's properly sharpened and my cutting technique is passable. I don't mind if it takes a while, and practicing has been fun, but it would be nice to know what the goal should be regardless of how long it takes to get there. Any tips you might have are of course also welcome!

Incidentally I'm also getting a Takamura R2 - this is the knife I was looking at first, but it seemed out of stock everywhere in Europe, so I looked at other options and eventually bought the Kaeru. Now that the Takamura came back into stock I couldn't resist it, but I promise that's my last knife! ;) Anyway it will give me another point of comparison, at least if I'm luckier with the factory edge this time.
 

NO ChoP!

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800 grit is low enough to actual remove metal. If your technique isn't solid, and you are wobbling at all with your strokes, you will only be convexing your bevels, and inturn the performance will diminish. Slow, rock steady passes; zero wobble is key. It's factory fresh, so should only take literally a few passes per side to expose fresh metal.

I think 800 is too low as a beginner stone, or a "one and done" stone. I would've suggested a 1500, 2000 or 3000 grit, personally.

The point of sharpening is to maintain your acute angle and to remove only fatigued metal. Anything more is only causing premature wear.

So many spend so much time on the stones; full progressions. This only lends to having to do these full jobs more frequently ( and shortening the life of your expensive knife). Remember, less is more.
 

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Also, stainless is much more prone to wire edges. Try running the edge into a wine cork, or directly into a soft piece of wood. A few light strokes usually does the trick. I would then return to your well slurried stone and do a few very light finishing strokes, ending with edge trailing.
 

Bart.s

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Shop from the Netherlands, ask them if they ship to Finland.

I think that the NP800 actually is a good first stone. Good for sharpening and can get a decent edge on them, perhaps followed by some stroppig on newspaper/jeans. It's a quality stone and you could later on expand with the NP400, NP2000 or NP3000. The NP800 is quite hard and in my experience, harder stones tend to be less forgiving on bad technique than softer stones, so it will teach you good technique.

As for the sharpening, get a sharpy and only do some edge trailing strokes with some pressure. Really try to focus on keeping your strokes as consistant as possible. Check your work regarly. Deburr with some light strokes.
 

4phantom

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To be perfectly honest, if you've never sharpened before it's probably your technique. I got a kaeru 210 stainless and sharpened it for my friend before he gave it to his parents as a present and the performance on it was superb after a quick touch up on my chosera 3k. (Never prepped a meal with it but got it to pass all the cut tests, e.g newspaper/shave/s cut in a paper towel)


If you're new to sharpening it's good to practice on a few beater knives before doing it on your 'good' knives because if you care about aesthetics/longevity it's likely you're going to fall into the mistakes that everyone makes when they first start, like wobbling a lot which causes scratches along the blade road and also doesn't help your sharpening or holding an incorrect angle, oversharpening (thus reducing the lifespan of your knife).

Also, because crappy cheap stainless is so ridiculously soft, once you compare it to well heat treated steels like the ones you'll find in your knives you'll find it much easier to sharpen in comparison.


When you're comfortable with passing basic cut tests on your beater knives then you should be all set to go on your new kaeru and takamura. Tests a paper towel cut test, newspaper cut test, shaving etc. The regular printer paper cut test is a pretty low bar to set for sharpness.

As others have said, sharpie trick is king and if you 100% sure you're getting an even burr then the main issue you'll have is properly deburring.
 

kryft

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800 grit is low enough to actual remove metal. If your technique isn't solid, and you are wobbling at all with your strokes, you will only be convexing your bevels, and inturn the performance will diminish. Slow, rock steady passes; zero wobble is key. It's factory fresh, so should only take literally a few passes per side to expose fresh metal.

Thanks, this was enlightening! I knew avoiding wobble was important, but no one had talked about what exactly happens when you do wobble. As soon as you said 'convexing bevel' I realized that with theoretical zero wobble your bevel would be perfectly flat, and as you increase the amount of wobble, the bevel will become increasingly convex. It makes sense that this would decrease cutting performance.

I'm sure you're right that it would have taken very little sharpening (or metal removal) to get the factory edge scary sharp if I had known what I was doing! Unfortunately the damage is already done: I've already raised a burr three times, and it's possible that the edge is now worse than the factory edge.

Is there a way to tell how convex the bevels are, and what's the best way to fix that? Can I just strop on the stone (perform sharpening motions with light to nonexistent pressure)? That's basically what I've been doing after my last burr formation, spending a bit more time on the tip area which seemed duller and felt different on the stone as well. I managed to reduce the discrepancy between the tip and the rest of the blade and also make it sharper overall.

For what it's worth, at least I didn't remove any sharpie above the bevel on my last burr formation pass.
 

kryft

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Shop from the Netherlands, ask them if they ship to Finland.

Yes, that's exactly where I bought it last Friday! I expect it will be shipped today. :)

I think that the NP800 actually is a good first stone. Good for sharpening and can get a decent edge on them, perhaps followed by some stroppig on newspaper/jeans. It's a quality stone and you could later on expand with the NP400, NP2000 or NP3000. The NP800 is quite hard and in my experience, harder stones tend to be less forgiving on bad technique than softer stones, so it will teach you good technique.

Right, I got the NP800 because many people recommended starting with either that or the Shapton Pro 1000.
 

kryft

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To be perfectly honest, if you've never sharpened before it's probably your technique. I got a kaeru 210 stainless and sharpened it for my friend before he gave it to his parents as a present and the performance on it was superb after a quick touch up on my chosera 3k. (Never prepped a meal with it but got it to pass all the cut tests, e.g newspaper/shave/s cut in a paper towel)

Yes, I'm convinced it's just my technique. :) But at the moment I also don't know how to tell when my technique is good enough: what sharp feels like in practice, like what cutting an onion should feel like with a knife with this type of edge geometry. Or where I should set the bar when testing sharpness after sharpening. So your reply is exactly what I was looking for, thanks!

If you're new to sharpening it's good to practice on a few beater knives before doing it on your 'good' knives because if you care about aesthetics/longevity it's likely you're going to fall into the mistakes that everyone makes when they first start, like wobbling a lot which causes scratches along the blade road and also doesn't help your sharpening or holding an incorrect angle, oversharpening (thus reducing the lifespan of your knife).

I'm afraid the damage is already done to some extent, but I can of course practice on beater knives now before returning to clean up my mess on the Kaeru. :) Would a Wüsthof Classic count as a beater knife? It's the only other knife I own at the moment, although I did consider buying a Victorinox Fibrox out of curiosity. (I don't know if I was lucky, but the Wüsthof actually felt quite easy to sharpen. My very first sharpening session was with the Kaeru, and after that I tried the Wüsthof and got much better results. 🤷‍♂️)

When you're comfortable with passing basic cut tests on your beater knives then you should be all set to go on your new kaeru and takamura. Tests a paper towel cut test, newspaper cut test, shaving etc. The regular printer paper cut test is a pretty low bar to set for sharpness.

Is the paper towel test being able to cut a paper towel that you're holding on your hand from the top to the bottom cleanly (no tears and minimal 'fuzz') with every part of the edge? Or should you be able to cut a hanging paper towel from the side?

And is the shaving test about removing a couple of hairs as you move the blade across the skin, or more like most of it? :D

As others have said, sharpie trick is king and if you 100% sure you're getting an even burr then the main issue you'll have is properly deburring.

I've been using the sharpie religiously, and at least in my last burr formation session I didn't remove sharpie above the bevel. But I guess that just means that I never wobbled below the bevel angle, and may have wobbled above it with abandon. In general I'm still unsure about what counts as 'even' or 'no wobble', since there's always going to be some error, and I'm still at the point where every sharpening session reveals errors that I wasn't capable of seeing before. The first two times I raised a burr, deburring was suspiciously quick, and I suspect I just couldn't feel the burr once it was small enough.
 

Dhoff

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Magic marker is your friend, it allowed you go see how consistent you are in passes :)
 

4phantom

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Yes, I'm convinced it's just my technique. :) But at the moment I also don't know how to tell when my technique is good enough: what sharp feels like in practice, like what cutting an onion should feel like with a knife with this type of edge geometry. Or where I should set the bar when testing sharpness after sharpening. So your reply is exactly what I was looking for, thanks!



I'm afraid the damage is already done to some extent, but I can of course practice on beater knives now before returning to clean up my mess on the Kaeru. :) Would a Wüsthof Classic count as a beater knife? It's the only other knife I own at the moment, although I did consider buying a Victorinox Fibrox out of curiosity. (I don't know if I was lucky, but the Wüsthof actually felt quite easy to sharpen. My very first sharpening session was with the Kaeru, and after that I tried the Wüsthof and got much better results. 🤷‍♂️)



Is the paper towel test being able to cut a paper towel that you're holding on your hand from the top to the bottom cleanly (no tears and minimal 'fuzz') with every part of the edge? Or should you be able to cut a hanging paper towel from the side?

And is the shaving test about removing a couple of hairs as you move the blade across the skin, or more like most of it? :D



I've been using the sharpie religiously, and at least in my last burr formation session I didn't remove sharpie above the bevel. But I guess that just means that I never wobbled below the bevel angle, and may have wobbled above it with abandon. In general I'm still unsure about what counts as 'even' or 'no wobble', since there's always going to be some error, and I'm still at the point where every sharpening session reveals errors that I wasn't capable of seeing before. The first two times I raised a burr, deburring was suspiciously quick, and I suspect I just couldn't feel the burr once it was small enough.

Wusthof classic can for sure be a beater knife (a bit on the expensive side but the steel quality is not bad, its more about whether you're willing to sacrifice a bit of your wusthofs longevity to improve your sharpening skills) , if you wanted to invest money in learning how to sharpen a vnox fibrox is a great option, however there are plenty of other ways to circumvent this. Offer to sharpen relatives knives, or even local neighbours. When I first started I offered on a local community forum and I got like 20 people offer to give me 5+ knives each and I got heaps of practice on other peoples knives. Of course, put a disclaimer in there that you are new and they shouldn't expect professional level results, but keep in mind most people will have stupidly blunt knives that haven't been touched for years so their standards will be pretty low.

The way I do the paper towel test is just by holding it on one side and seeing if I can slice through it. Slicing is a good place to start, when you start to get better and better you'll be able to push cut it without the slicing motion, but thats a fairly high standard to set yourself to. You don't need to go all the way through the paper towel if you're slicing, and yes you want minimal fuzz and ideally no tearing.

Shaving test depends on how high your standards are. For starting out, if you can remove most of your hair in a few passes you're doing well. As you get more proficient you'll start to need less passes to get hair off.
 

kryft

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Wusthof classic can for sure be a beater knife (a bit on the expensive side but the steel quality is not bad, its more about whether you're willing to sacrifice a bit of your wusthofs longevity to improve your sharpening skills) , if you wanted to invest money in learning how to sharpen a vnox fibrox is a great option, however there are plenty of other ways to circumvent this. Offer to sharpen relatives knives, or even local neighbours. When I first started I offered on a local community forum and I got like 20 people offer to give me 5+ knives each and I got heaps of practice on other peoples knives. Of course, put a disclaimer in there that you are new and they shouldn't expect professional level results, but keep in mind most people will have stupidly blunt knives that haven't been touched for years so their standards will be pretty low.

The way I do the paper towel test is just by holding it on one side and seeing if I can slice through it. Slicing is a good place to start, when you start to get better and better you'll be able to push cut it without the slicing motion, but thats a fairly high standard to set yourself to. You don't need to go all the way through the paper towel if you're slicing, and yes you want minimal fuzz and ideally no tearing.

Shaving test depends on how high your standards are. For starting out, if you can remove most of your hair in a few passes you're doing well. As you get more proficient you'll start to need less passes to get hair off.

Thanks, really helpful! By the way, since you sharpened a Kaeru once, do you happen to remember whether the grind was asymmetric or not? It looks a little asymmetric to me when I look at the choil, but I'm not 100% sure. To add to the confusion, one person has told me that it is asymmetric, and another person has told me that it's not. :)

I noticed that although each bevel was pretty consistent on its own, I seem to have made the right bevel wider than the left on. (It's a little hard to tell what the angle is when the spine is facing away from me, even if I can keep that angle fairly consistent.) I did try to follow the factory angles, but I may have done a bad job. On the other hand, if the grind is asymmetric, then maybe the original bevels were too. I'm not sure how much this matters.
 

tostadas

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Thanks, really helpful! By the way, since you sharpened a Kaeru once, do you happen to remember whether the grind was asymmetric or not? It looks a little asymmetric to me when I look at the choil, but I'm not 100% sure. To add to the confusion, one person has told me that it is asymmetric, and another person has told me that it's not. :)

I noticed that although each bevel was pretty consistent on its own, I seem to have made the right bevel wider than the left on. (It's a little hard to tell what the angle is when the spine is facing away from me, even if I can keep that angle fairly consistent.) I did try to follow the factory angles, but I may have done a bad job. On the other hand, if the grind is asymmetric, then maybe the original bevels were too. I'm not sure how much this matters.
To get a rough idea of the overall grind, you can lay a flat edge (edge of ruler or credit card) along the blade face going from spine to edge, and look to see where the light comes through as you move the card. If it's asymmetric, typically one side will be more flat (less light coming through) than the other.
 

kryft

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To get a rough idea of the overall grind, you can lay a flat edge (edge of ruler or credit card) along the blade face going from spine to edge, and look to see where the light comes through as you move the card. If it's asymmetric, typically one side will be more flat (less light coming through) than the other.

Thanks, good tip. Seems like the right side is definitely a bit more convex than the left. In that case I guess having the right bevel a bit wider than the left may be helpful, or at least not a problem. If I understand correctly, the grind would cause the knife to steer a bit to the left, and having a wider bevel (smaller edge angle) on the right can compensate for that.
 

tostadas

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Thanks, good tip. Seems like the right side is definitely a bit more convex than the left. In that case I guess having the right bevel a bit wider than the left may be helpful, or at least not a problem. If I understand correctly, the grind would cause the knife to steer a bit to the left, and having a wider bevel (smaller edge angle) on the right can compensate for that.
 

kryft

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Thanks, this post is actually what I was thinking of when I wrote the above. :) Although I mistakenly thought that a wider bevel would mean that the angle is more acute because I was thinking of starting with a symmetric apex (equilateral triangle) and then grinding one side to be more acute, but that's not really how it works.

Oh well, I'll worry about this once the knife is actually sharp.
 
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