# Durability testing Watanabe Pro Gyuto



## stringer (Apr 9, 2019)

I usually put a micro bevel on my Watanabe to increase it's durability. I realized this morning after an hour or so of chopping zucchini that I must have forgotten last time I sharpened it. 
I glanced at the edge and it looked serrated. I decided to go ahead and finish the project I had started as a sort of durability test. So, here's what a Wat zero edge looks like if you use it to chop 400 pounds (180 kilos) of zucchini, summer squash, and eggplant into 1 inch dice on a cheap poly cutting board. 












And here's what my knife callous looks like:


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## rickbern (Apr 9, 2019)

Fingers held up better than the steel; go flesh!


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## inferno (Apr 9, 2019)

It happens. Not really surprising.


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## inferno (Apr 9, 2019)

It would be cool if you timed how long it took to fix that.


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## refcast (Apr 9, 2019)

Kinda like when I thought Heiji could go through salmon rib bones without a microbevel, just because it was fine through the first bone.


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## stringer (Apr 9, 2019)

inferno said:


> It would be cool if you timed how long it took to fix that.



The repair

Round 1 - 90 seconds each side shapton glass 500






Round 2 - 90 seconds each side glass 500





Round 3 - 90 seconds shapton glass 500 each side






Round 4
SG500 45 seconds each side plus 45 alternating edge leading strokes, pulled it through some soft wood. Burr at this point was about .75 mm wide roughly. Looked like Tin foil on the edge





Round 5 - Shapton Pro 1000 60 seconds each side plus 60 edge leading alternating strokes, pulled through cork






Round 6 Naniwa Super Stone 2000 60 seconds each side plus 60 edge leading






To be continued


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## stringer (Apr 9, 2019)

Round 7 stropped on leather with green stuff 20 times alternating edge trailing

20 each alternating edge leading high angle passes for micro bevel/micro convexity. (Judging by today's damage I might have to be more aggressive here )






So it would have been about a fifteen minute job if I wasn't screwing around with the camera.


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## RDalman (Apr 10, 2019)

Awesome. You might even need to consider microbeveling on a higher angle on your 1k I think.
edit: just reread top post and yea you probably are on top of that normally.


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## lemeneid (Apr 10, 2019)

The edge retention on the Wat is amazing. Let us know again when you decide to sharpen again so we’ll know how far this knife can hold its edge.


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## stringer (Apr 10, 2019)

I haven't quite figured out how I want to do the microbevel yet. I've tried a couple of different ways. I love the feeling of the zero edge. It makes everything so ridiculously effortless. But obviously it's not a sustainable strategy if I'm going to use it for high volume, high speed vegetable processing. So I try and back it off just enough. Sometime I should measure the before and after sharpening height with my calipers. I don't think you actually have to go down to the depth of the deepest chip. Some of that chip must get filled in through burnishing. You move the metal to fill in the gap, scratch, chip, whatever. Burr formation is the most obvious example of this plastic nature of steel. It is like the leftover that wouldn't fit anywhere. But not all the steel is being pushed into the burr. Some is filling empty spaces. That's part of how stropping straight edge razors works too I think. Anyways, I'm sure you know all this. It was just very striking to me this time. Especially when I went to the 1000. That enormous visible burr, as well as 2 or 3 seemingly 1 mm deep remaining chips just disappear after like two minutes. You really see it when you do something like this on a knife that is really hard and really thin behind the edge. So maybe I'll just say screw the micro bevel. It's so fun and easy to sharpen. And I'm learning a lot. I'm interested to see how the s-grind geometry lasts with all the sharpening. Another thing I've noticed. Since I treat all my knives like they are extreme wide bevels. My knives get thinner, but they don't lose much height. So even knives I beat the crap out of and sharpen every day or every other day might only lose 1 mm every year. The guy with the grinder in his van takes 1.5 mm per sharpening. So I'm pretty comfortable with that. It's just a question of finding that balance between maintaining the amazing geometry and keeping it tough enough.


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## RDalman (Apr 10, 2019)

I like your sharpening approach. Bet this thread is helpful to many.


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## MrHiggins (Apr 10, 2019)

Stringer: the scratch pattern that's shown in your photos looks like you must just lay your knife down on the stone and go at it. Is that what you mean by zero grind - a constant angle all the way from spine to edge? 

I own a toyama (similar/identical to the Wat, I hear) and it has a convex right side and a flatter left side. I try to follow that convexity. Would your approach knock the convex down flat? Doesn't that kill food release?

Phew! Lots of questions!


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## stringer (Apr 10, 2019)

There's a bit of an optical illusion formed with this knife and the slurry that the iron cladding produces. My "bevel" is about halfway up the face of the knife, but it looks higher because of slurry polishing I think. I'll show some pics of stainless knives I sharpen this way when I get a chance. It's easier to see exactly where I'm sharpening. As far as the geometry. I'm sure I'm changing it a little, we will see what affect this has over time. But even if I'm eliminating a little convexity/concavity and altering the geometry in one sense, I'm staying true to the original thin behind the edgeness, which is more important for me. I've never found food release to be much of an issue with any knives I have used. Part of that is experience and technique. Part of that is I'm not much of a laser guy. And this is the first s-grind or something similar that I have owned so who knows, maybe it will develop horrible stickiness over time. I'll take choil shots so I can be sure to monitor any changes. And I'll post a video from home sometime.


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## Gregmega (Apr 10, 2019)

I feel you on the zero/micro debate. I finally succumbed to just having to add the micro bevel with the stress I put on mine.
I gotta say- it’s refreshing to see that you don’t remove all the micro chips, I don’t think it’s necessary and rarely do myself. It’s also refreshing to see someone use their knives to the limit of their abilities. Some of my friends are mortified that I actually ‘use’ my knives.. [emoji23][emoji41]


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## Gregmega (Apr 10, 2019)

By the way- 400lbs??!! Go Watanabe!


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## stringer (Apr 10, 2019)

Here's some pics of some stainless knives that are sharpened the same way. It's more clear where I'm aiming for with monosteels.

180 semi stainless petty





210 stainless petty/suji







This last one is the most extreme. 240 semistainless kanehide. It gets sharpened more often and used more often than any knife I've ever owned. I pretty much do a full flat grind. You can see a tiny skinny little bit that doesn't get sharpened near the spine. After I raise a burr with the full flat then I do a very slight micro. But this steel is extremely tough. Doesn't get as sharp as my gingas or wats, but it very very seldom chips. Usually only if I loan it out.


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## swarth (Apr 10, 2019)

some people are afraid to sharpen because they scratch their knives...


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## DitmasPork (Apr 10, 2019)

stringer said:


> Here's some pics of some stainless knives that are sharpened the same way. It's more clear where I'm aiming for with monosteels.
> 
> 180 semi stainless petty
> 
> ...



Wonderful post you've done, dig seeing how you go about sharpening your Watanabe—pragmatic, just get it done approach. BTW, love that custom Clif Bar saya.


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## Gregmega (Apr 10, 2019)

Hahaha yes! Cliff bar saya!


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## JBroida (Apr 10, 2019)

my friend KC used to sharpen like this... his knives were crazy brittle. It was ok if he was the only one using them (they still chipped a bit), but if anyone else picked them up, they got super messed up really quickly


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## panda (Apr 10, 2019)

JBroida said:


> my friend KC used to sharpen like this... his knives were crazy brittle. It was ok if he was the only one using them (they still chipped a bit), but if anyone else picked them up, they got super messed up really quickly


Useless edge, lol.


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## stringer (Apr 10, 2019)

JBroida said:


> my friend KC used to sharpen like this... his knives were crazy brittle. It was ok if he was the only one using them (they still chipped a bit), but if anyone else picked them up, they got super messed up really quickly



I prefer my edges to be as thin as possible. If I start noticing edge rolling in softer steels or chipping in harder steels then I back off a bit. Other people use my knives all of the time. There is generally not an issue with brittleness. I do have one cook who I don't let use the Wat. He has a really annoying habit of cleaning stuff off of his blade by banging it sharp edge first against the lip of a hotel pan. He does use the Kanehide with the full flat grind pretty often. No issues. It is a fair bit softer than the Wat obviously. The only chips I have had with it have been from dropping it onto the floor.


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## John N (Apr 10, 2019)

Thats some shallow sharpening! do the chips end up in the food ?!


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## merlijny2k (Apr 11, 2019)

I find this sharpening style works best with thicker knives. Makes sense too as the angle towards the zero grind is less steep. I suppose a thin knife with a low bevel would work too. For a thin knife with high bevel it just gets too fragile for my taste. For that knife I use a regime of 1 zero grind, get few micro chips after bit of use, then sharpen them out at 'normal' 16 degree job, do that next five times, switch back to round of zero grind. I suppose doing the micro bevel right away actually makes more sense but it is just fun to have the zero grind ootb feel every now and again.


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## inferno (Apr 11, 2019)

I dont have any knife set up as a zero. I have noticed some of my edges got so thin and flimsy they simply bent into a wavy noodle when thinning. I always put a microbevel on there and sometimes its not even that micro either.


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## stringer (Apr 11, 2019)

merlijny2k said:


> I find this sharpening style works best with thicker knives. Makes sense too as the angle towards the zero grind is less steep. I suppose a thin knife with a low bevel would work too. For a thin knife with high bevel it just gets too fragile for my taste. For that knife I use a regime of 1 zero grind, get few micro chips after bit of use, then sharpen them out at 'normal' 16 degree job, do that next five times, switch back to round of zero grind. I suppose doing the micro bevel right away actually makes more sense but it is just fun to have the zero grind ootb feel every now and again.



This is similar to how I take care of things in normal practice. I don't usually have a knife that is as heavily damaged as the wat was this time. I only do a full progression zero grind reset once every couple of months. I add a micro bevel. In between full progressions, I touch up the micro bevel on the 2000 super stone or a ceramic hone. When I notice microchips, or I find the touch-ups aren't getting the knife as sharp as I prefer, then I do another full sharpening. For my knives that don't have a lot of board contact, like sujis and petties, I skip the microbevel, and can go about a year without a full progression sharpening. I will mention one other caveat about this sharpening strategy. It will obviously leave lots of extraneous scratch marks all over your blade that will affect the appearance. Less obviously at first, but more annoying in the long run, if your blade or cladding is highly reactive then you will have to establish a patina every time you sharpen or deal with lots of discolored fruit and onions.


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## Xenif (Apr 11, 2019)

merlijny2k said:


> I find this sharpening style works best with thicker knives. Makes sense too as the angle towards the zero grind is less steep. I suppose a thin knife with a low bevel would work too. For a thin knife with high bevel it just gets too fragile for my taste. For that knife I use a regime of 1 zero grind, get few micro chips after bit of use, then sharpen them out at 'normal' 16 degree job, do that next five times, switch back to round of zero grind. I suppose doing the micro bevel right away actually makes more sense but it is just fun to have the zero grind ootb feel every now and again.


That is for the most part my approach as well, reset to zero, check if I have messed up the profile at all, then use it with the zero edge and get giddy until the micro chip bothers me enough for me to put a micro bevel on them . 

This thread is great because its great to compare notes to our approaches, we all have different needs


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## Ivan Hersh (Apr 11, 2019)

What type blade steel does that knife have, sure seems of poor heat treat quality to me.


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## stringer (Apr 11, 2019)

Ivan Hersh said:


> What type blade steel does that knife have, sure seems of poor heat treat quality to me.



If you're asking about the Watanabe, it's blue 2. The heat treat is great as far as I can tell. It's by far the hardest knife I have owned, maybe 63. I've owned a dozen plus in the 59-61 range. But nothing past that, so I'm learning as I go. And I want to be clear, I'm providing this info as my personal experiences and what works for me. I have hundreds of hours experience sharpening, but I have tens of thousands hours experience cutting stuff up. My approach is designed by a chef for a chef. Wide bevel knives are faster and easier to sharpen. So I just turn all knives into wide bevel knives. At home this strategy is probably more than overkill.
With all those caveats in mind, I have never had the ability to get an edge as sharp as this method on the Watanabe. But just because you can get a blade sharp enough to split a dropped hair, doesn't mean you should use such a sharpened blade to cut bushels of veggies on an unforgiving color coded plastic board. I need to be more careful to remember to micro bevel. 
And like Dalman said, start my micro bevel sharpening earlier when doing a full progression. 
I did use the knife quite a bit today. It was a little too sharp still at first. I cut the micro bevel in some more with a white Mac ceramic rod until it stopped digging into the cutting board. Then I did about 8 pounds of brunoise mirepoix and a pound of garlic for Bolognese. No micro chips, no issues. I will try and refrain from sharpening it until it really needs a touch-up and I'll keep track of what I use it for. I only pull it out for big jobs that would take one of my cooks too long to complete. So it should be easy to guesstimate.


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## Nemo (Apr 11, 2019)

Ivan Hersh said:


> What type blade steel does that knife have, sure seems of poor heat treat quality to me.


My 2 Bobs' (2 cents') worth:

Watanabe's blue2 is a pretty hard HT. Hard means it will hold a pretty acute edge without rolling over but will be prone to (micro)chips if the edge is too acute for the type of work you are doing. Another way of saying this is that the mode of failure of the edge will be chipping rather than rolling, even if this failure occurs at a higher threshold.

I think that Watanabe usually ships his knives with a zero grind, which makes them very sharp (I'm guessing this is under 10 degrees inclusive) but probably not durable enough for rough use (as I assume one would encounter in a busy pro kitchen). I think that he expects that you will put a microbevel on it if appropriate for your type of use.

In my more gentle home use, the zero grind actually lasted a while. Now that I have microbevelled it, this hard steel has very good edge retention, even for blue 2.

It's also pretty nice to sharpen, even if it feels a little different (maybe harder?) to softer HTs of blue 2.

I would say that it's a good HT but one that requires care and attention because it is pushing hardness toward the limit.


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## Ivan Hersh (Apr 11, 2019)

Look at Carter Cutlery and look at his white steel kitchen knives.


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## stringer (Apr 11, 2019)

When your knife chips out, it doesn't usually chip out big chunks at a time unless you're abusing it. So the process starts with micro chips that are invisible. These grow. There are iron particles in fortified flour that are bigger than what you are losing through these microchips. Over time, however, they accumulate. They especially get bigger and bigger where you are doing the most work. You can see the biggest chips where I generally make the most board contact.

A knife being used carefully at home will not accumulate that much damage. 400 pounds of veggies is a lot. It gets delivered off the truck with a forklift on a palette with a bunch of other stuff. Then it gets put onto a 8 foot flatbed cart to be delivered to my kitchen. The zucchini and squash come in about 25 pound cases and the eggplant is about a 35 pound case. I think I did 5 cases each of zucchini and squash and 4 cases of eggplant. This was enough to fill 14 heaping roasting pans like the one below. It took me a couple of hours to chop and I am quick. My knives see this kind of activity regularly. They probably sustain more damage during a session like this than a home cook could generate in a year. The Kanehide, at around 60 Rockwell would be rounded and dulled after that much work. It would at least need a touch-up.
Despite all those chips, the Watanabe was still sharp enough to shave.
The Watanabe with a proper micro bevel could do this task 3 or 4 times before it would have that many microchips. And it will never really round off. Like Nemo said, that failure mechanism is unavailable. The carbides don't round but they will break off.

https://www.amazon.com/Winware-Aluminum-Roast-Pan-Inch/dp/B001CIEJT2/

Edited to fix link


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## stringer (Apr 11, 2019)

Ivan Hersh said:


> Look at Carter Cutlery and look at his white steel kitchen knives.



I have handled a couple of Mutekis. I find them pretty interesting. I like the thick spines, distal taper, tall heel height. They look cool. They are comfortable. But they are also a little short for my tastes. The ones I've seen are mostly 210s. And they are hella expensive. I think next I will try something that's real hard and meant to be more of a wide bevel like a heiji. I'm also working on some of my own creations. I'm damn proficient from a technical standpoint with a utilitarian 60 HRC edge. It's all I ever really need to do my job. 
Going beyond that is mostly just because I love knives, so who knows maybe I'll try a Carter someday, but for now I'd probably rather spend that money on a Mazaki and a Wakui and a natural stone.


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## Michi (Apr 11, 2019)

stringer said:


> I think next I will try something that's real hard and meant to be more of a wide bevel like a heiji.


Just out of curiosity… If you want hard, I would think that ZDP-189 or HAP-40 would provide that. Any particular reason for not using these?


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## lemeneid (Apr 11, 2019)

Michi said:


> Just out of curiosity… If you want hard, I would think that ZDP-189 or HAP-40 would provide that. Any particular reason for not using these?


Pain in the ass to sharpen? I would guess that would be a dealbreaker for pro chefs.

Also if you’ve seen Kip’s sukenari ZDP repair, that stuff isn’t fun.


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## Nemo (Apr 11, 2019)

stringer said:


> A knife being used carefully at home will not accumulate that much damage. 400 pounds of veggies is a lot. It gets delivered off the truck with a forklift on a palette with a bunch of other stuff. Then it gets put onto a 8 foot flatbed cart to be delivered to my kitchen. The zucchini and squash come in about 25 pound cases and the eggplant is about a 35 pound case. I think I did 5 cases each of zucchini and squash and 4 cases of eggplant. This was enough to fill 14 heaping roasting pans like the one below. It took me a couple of hours to chop and I am quick. My knives see this kind of activity regularly. They probably sustain more damage during a session like this than a home cook could generate in a year. The Kanehide, at around 60 Rockwell would be rounded and dulled after that much work. It would at least need a touch-up.
> Despite all those chips, the Watanabe was still sharp enough to shave.
> The Watanabe with a proper micro bevel could do this task 3 or 4 times before it would have that many microchips. And it will never really round off. Like Nemo said, that failure mechanism is unavailable. The carbides don't round but they will break off.



Yeah, I think you guys put your knives through a much rougher time than we home cooks do. I suspect that you are much better able to compare edge retention because of it.


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## labor of love (Apr 12, 2019)

Heiji Carbon is my fave carbon steel. You should definitely dive right in if you haven’t already.


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## labor of love (Apr 12, 2019)

Carters seem to differ quite a bit in every way except for thinness. It’s an art to find the right length/profile/tip and handle combo for any particular user.


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## Michi (Apr 12, 2019)

lemeneid said:


> Pain in the ass to sharpen? I would guess that would be a dealbreaker for pro chefs.


Well, I'm not sure I'd put it as extreme as that. ZDP-189 and HAP-40 are definitely harder to sharpen than blue, white, or VG-10 (or even SG-2). But, with a bit of patience, it works out just fine, IMO. I guess it's not reasonable to expect extreme edge retention without having to compromise somewhere else, such as sharpening time.

But, yes, time may well be a reason. I'm not a chef, so I have no idea where the balance between edge retention and sharpening time tips in the wrong direction in a professional environment.


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## stringer (Apr 12, 2019)

Michi said:


> Just out of curiosity… If you want hard, I would think that ZDP-189 or HAP-40 would provide that. Any particular reason for not using these?



Definitely on the someday list. I have not tried any powdered/sprayform steel yet. Difficulty of sharpening is the main drawback. But I've been looking longingly at Takamura and Sukenari for a while. Eventually I will succumb to the temptation I'm sure.


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## Luftmensch (Apr 12, 2019)

Impressive post. Kudos!



stringer said:


> Definitely on the someday list. I have not tried any powdered/sprayform steel yet. Difficulty of sharpening is the main drawback. But I've been looking longingly at Takamura and Sukenari for a while. Eventually I will succumb to the temptation I'm sure.



Gah.... I am going to sound like a Gihei shill... You might have seen... I just recommended him on another thread - a Sanjo blacksmith who makes stainless clad ZDP knives. I would be interested to see how that steel compares. The failure mode is chipping.

I can't speak to the original grind (years later I forget what it was like). I made it my own - i thinned it, made it convex/hamaguri and fixed up the bevel line aesthetics. With the convex grind the primary bevel and micro bevel are part of the same process. Every time I do this 'reset' I will refinish the face using wet and dry sand paper to restore the brushed steel look. In this condition there will not be a defined bevel line. If the knife gets dull I will resharpen using a micro bevel. At this point you will be able to see a micro bevel line. I might do this three or so times before performing another 'reset'. Most of the faffing about is getting nice aesthetics. If you didn't care you could save a lot of time.

ZDP is less fun to sharpen. It is more work. You are sticking to low grits with fast synthetics though - so it might not be the ordeal some make it out to be.

As a home cook I don't need to sharpen often at all. The ZDP holds an 'acceptable' edge for a long time. We are omnivores but our diet is biased towards vegetables. The 'acceptable' edge might not be the best for perfect protein cuts or delicate cuts like tomato (not that it is terrible) but it does the rest competently. Zucchini and eggplant are on the menu a lot in our house - definitely no issues.

How sharp is 'acceptable'? It is subjective isn't it? These are my 'beater' knives. I deliberately don't obsess over their sharpness. Right now they are overdue for resharpening - so they are perhaps beyond 'acceptable'. Yet they are 'shaving' sharp. Even this is subjective? I can remove hairs but it is rough, requires pressure and exfoliates skin... NOT something i would shave with! I cant remember when I last sharpened them.... maybe four to six moths ago (daily use since then).


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## Michi (Apr 12, 2019)

Luftmensch said:


> As a home cook I don't need to sharpen often at all. The ZDP holds an 'acceptable' edge for a long time. We are omnivores but our diet is biased towards vegetables. The 'acceptable' edge might not be the best for perfect protein cuts or delicate cuts like tomato (not that it is terrible) but it does the rest competently.


LIKE

Thank you for injecting some pragmatism!

When I'm cooking (as much as I enjoy it), much of the time, I just need to turn large things into smaller things (sometimes in a hurry, because I'm late for work or have guests arriving in ten minutes). In that case, I couldn't care less about how amazing it is that I managed to cut into the skin of a tomato with 50 µg less pressure than last time, before I sharpened the knife. It the knife goes through a tomato without tearing, pretty much by definition, that's a working knife.

I'm into obsessing about knives as much as most people; but I also try not to forget that the point of the exercise is the food, not the knife.


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## stringer (Apr 12, 2019)

I don't really care about shaving sharp. My tests are much more practical.
One of my main tests for sharpness in the kitchen for gyutos is eggplant. Eggplant skin is weird. A "dull" knife just bounces off it. A nice refined toothy apexed 2000 grit edge should experience no issues. Here is how many pounds of eggplant you would have to chop with the following options from my kit before it fails the eggplant test. (this is a guess, but very educated)

Montana 10" Chef Knife 10 pounds
Dexter 8" stainless Chinese Cleaver 100 pounds
Vintage Sabatier Workhorse Grind Carbon 10" 300 pounds
Kanehide TK 240 500 pounds

Watanabe. I don't believe that it would ever fail this test. After a few thousand pounds the edge would look like a sharks mouth but it will cut the eggplant skin easily.


Now my other test for sharpness/edge retention examines the opposite side of the equation. Toughness. I haven't carried a serrated knife in my kit since I lost mine the second week of culinary school many years ago. I had no money to buy another one. So I started using a chef knife for everything you would use a serrated knife for. Never looked back. The Kanehide fulfills that role in my current kit. It routinely slices a 96 count of this case of crusty french french baguette into 1/16" slices.

https://www.aryztaamericas.com/food-services/french-demi-baguette

I would call it a light middleweight out of the box. Not quite a laser. After 3 or 4 years of being sharpened with a full flat grind zero edge it's definitely a laser now. Despite that, nothing holds a candle to the Kanehide on this test. It cuts cleanly through the bread forever. And never chips. The Watanabe can do this job fine. But even with a micro bevel it will quickly start accumulating chip damage.

Like everything with knives there's opportunity costs to every decision. The Watanabe is my go to for veggie fabrication. The Kanehide is a great all rounder. And I can leave it on the prep table and loan it out to people and know that they will have a tough time breaking it.


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## HRC_64 (Apr 12, 2019)

stringer said:


> ...Despite all those chips, the Watanabe was still sharp enough to shave....


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## Luftmensch (Apr 12, 2019)

Michi said:


> LIKE
> 
> Thank you for injecting some pragmatism!



Thank you Michi - that is kind.



Michi said:


> I just need to turn large things into smaller things



I love a good reductionist view!



Michi said:


> I'm into obsessing about knives as much as most people; but I also try not to forget that the point of the exercise is the food, not the knife.



Definitely a healthy perspective. I suppose obsession is part of the journey? Getting the ultimate edge is about pursuing better standards and increasing skill level. While this is good validation of technique it does lose the forest for the trees.

I got into free-hand sharpening through straight razors. I wasted a lot of time being obsessional there. When I translated that knowledge to kitchen knives, I never really felt the need to see how much sharper I could get. Enough to get the job done was always sufficient!


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## Luftmensch (Apr 12, 2019)

stringer said:


> One of my main tests for sharpness in the kitchen for gyutos is eggplant. Eggplant skin is weird. A "dull" knife just bounces off it. A nice refined toothy apexed 2000 grit edge should experience no issues.



This is true! The skin is tough stuff isnt it? Very rubbery. A nice toothy edge does help rupture the surface.



stringer said:


> Watanabe. I don't believe that it would ever fail this test.



I guess this comes back to the primary failure mode of the edge? Chipping create teeth to saw through skins.



stringer said:


> Now my other test for sharpness/edge retention examines the opposite side of the equation. Toughness. I haven't carried a serrated knife in my kit since I lost mine the second week of culinary school many years ago. I had no money to buy another one. So I started using a chef knife for everything you would use a serrated knife for. Never looked back.



We do the same. Far less crumbs too! Never owned a serrated knife and I have no desire. 



stringer said:


> The Watanabe can do this job fine. But even with a micro bevel it will quickly start accumulating chip damage.



Surely not from the bread though!? Unless your edge is that thin? That is 96x16 cuts with the same amount of possible board impacts?



stringer said:


> The Kanehide is a great all rounder. And I can leave it on the prep table and loan it out to people and know that they will have a tough time breaking it.



I guess that is the problem with hard knives... they are less tough! Hence the chipping. Lower the hardness and you get better toughness but are less able to hold an edge.


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## stringer (Apr 12, 2019)

Luftmensch said:


> This is true! The skin is tough stuff isnt it? Very rubbery. A nice toothy edge does help rupture the surface.
> 
> 
> 
> ...



The way I cut baguette there is plenty of board contact. And I meant 1/16 inch thick slices. That's probably an exaggeration, let's say 1/8 inch slices. On the bias. We toss them with olive oil and toast them to serve with cheese and charcuterie. Each loaf makes 25-30 slices. 96 loaves. Speed is of the essence. It's pretty tough on hard steel.


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## K813zra (Apr 12, 2019)

I don't know what kind of bread you all deal with but when I lived in Spain every bakery had a few types of rustic bread that could mess up a thin edge on a gyuto without a seconds hesitation. I mean concrete hard crust and that really is not an exaggeration. I have cut and jabbed myself with such crust in the past. I found a serrated knife was almost a must. Baguettes were quite soft in comparison, quite soft. I've never seen bread that hard stateside, ever. (The inside is still quite fluffy but not like the Italian/French loaves you get around here.)

Man, I miss that bread. Good stuff for some toasta catalana.


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## inferno (Apr 12, 2019)

stringer said:


> Definitely on the someday list. I have not tried any powdered/sprayform steel yet. Difficulty of sharpening is the main drawback. But I've been looking longingly at Takamura and Sukenari for a while. Eventually I will succumb to the temptation I'm sure.



If you were to do what you just did to a zdp/real HSS/r2/srs-15/s30v and similar high carbide especially high V% it would take between 2-10X as long  just so you know. 

I once did a test with an aus-8 cryoed blade (mac) and a kurosaki r2. both finished at 4k glass. I cut cardboard for at least 30 minutes with each knife. It might have been longer. And at the end of the test the kurosaki chipped out kinda microchips. But all over the blade. There must have been 100-200 or so.

the mac just kinda dulled/rouded off gently. not a single chip. not even microscopically. 

And halfway in both knives were equally sharp! at the end of the test no knife was sharp. this was a test of the failure mode though. i wanted to see _how_ they dulled. 

Aus-8 can actually be quite badass if you ask me. especially the cryoed macs. I regard aus-8 as more of a supersteel than r2 to be honest. not mentioning zdp... yuck. 

Best part about it was the sharpening to restore the edges. the mac took like 2-3 minutes or so. it was a very short amount of time at least. The r2 took about 10x as long. 

So i think maybe you should go for something in between carbon and supersteels/hss/ss-hss instead of getting supersteels just because its the flavor of the month. Taking sharpening time in consideration there is really no benefit for the supersteels. I have tested it.


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## DitmasPork (Apr 12, 2019)

labor of love said:


> Heiji Carbon is my fave carbon steel. You should definitely dive right in if you haven’t already.


What do you like about Heiji's carbon—quite a few sings its praises—I've only used his SS. Do you find it chippy?


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## labor of love (Apr 12, 2019)

DitmasPork said:


> What do you like about Heiji's carbon—quite a few sings its praises—I've only used his SS. Do you find it chippy?


It’s supposed to be on the brittle side but I’ve never had that problem. Then again I’ve never pushed it too a very low angle like stringer does, but I want to. It just encapsulates the carbon experience, easy to sharpen, gets crazy sharp and edge retention isn’t as good as watanabe but it’s no slouch either.


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## inferno (Apr 12, 2019)

i feel even the cheapest blue 2 knives like the blue moon are easy to sharpen, gets crazy sharp (most likely the most crazy of anything out there) and has more than sufficient edge retention myself though. and are very tough. comparatively. blue 2: _the only true supersteel _(no joke).


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## stringer (Apr 12, 2019)

inferno said:


> If you were to do what you just did to a zdp/real HSS/r2/srs-15/s30v and similar high carbide especially high V% it would take between 2-10X as long  just so you know.
> 
> I once did a test with an aus-8 cryoed blade (mac) and a kurosaki r2. both finished at 4k glass. I cut cardboard for at least 30 minutes with each knife. It might have been longer. And at the end of the test the kurosaki chipped out kinda microchips. But all over the blade. There must have been 100-200 or so.
> 
> ...



I followed that thread. And the research I've done supports your conclusions. I'm not doing sushi work or delicate fine dining stuff at the moment. It's just ordinary big hotel banquet and buffet stuff. Carbon is too finicky, super steels too hard to sharpen to bash against polycarbonate all day. Although they would probably be great for a slicer. My 270 Ginga in white #2 stays sharp for ages just cutting cooked proteins. I can't imagine how long something in zdp-189 would last.
For everyday gyutos I'm thinking premium semi-stainless next. Heiji, yoshikane skd, and custom aeb-l are up there on my wish list. I figure they are the closest to the Kanehide upgraded. Or even some upscale vg-10. It's a difficult steel to learn to sharpen but once you know how to remove every trace of a burr, it really is nice and easy to keep sharp with minimal maintenance and super tough compared to simple carbon.


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## inferno (Apr 12, 2019)

stringer said:


> For everyday gyutos I'm thinking premium semi-stainless next. Heiji, yoshikane skd, and custom aeb-l are up there on my wish list. I figure they are the closest to the Kanehide upgraded. Or even some upscale vg-10. It's a difficult steel to learn to sharpen but once you know how to remove every trace of a burr, it really is nice and easy to keep sharp with minimal maintenance and super tough compared to simple carbon.



I have a yoshikane skd11 hammered santoku. I sh1t you not when i tell you it takes a 12k shapton pro edge and gets so sharp its actually scary. And I'm used to sharp knives obviously. This is japanese D2, one of the very coarsest tool steels, with the biggest mutha F carbides ever in existence supposedly. But hey guess what? It takes a 12k edge  contrary to popular belief. 

Vg10 is really not that bad imo. Its actally one of the better stainless steel overall. Yeah you will get 100 trillion reviews of vg10 chipping out and vg10 being hard to sharpen. And to be honest I have not found this to be true for my knives. But hey sh1t in sh1t out. you wanna pay 50 bux what you gonna expect? 

vg10 is actually very easy to sharpen, and very tough, and holds a "razor" edge for quite some time and a "workable edge" for very long. 

Almost all vg10 knives are overheated from the factory on belt sanders so they have brittle edges. they basically re-austenitized them without tempering them. So you have to grind off 1mm or so and then its all good metal there. and you obviously know how to grind off some metal. 

I think aus-8 is also good and also steels like 13c26/aeb-l and also vg-1/vg-5. Aus-8 is actually my fav stainless. Since it gets so sharp fast (like blue 2) and also sharpens very fast and easy (like blue 2). Aaaand STILL holds a very good, very sharp edge for very long, talking that fresh off the stone sharpness. I think aus-8 is the most underestimated steel from japan. It can be just as good/durable as r2 but like 3x as tough. go figure.


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## dgib7994 (Apr 12, 2019)

Awesome post! Loved seeing that method of sharpening. I'd love to try it out sometime. I've only ever thinned, though never all the way to zero, and then put a normal edge bevel on. How do you manipulate angle and pressure to get that edge to zero? Might be missing something simple but I've had trouble on my wide bevels knives. Perhaps I'm not switching my pressure low enough on the knife to achieve true zero when attempting hamiguriba.

In fact, I just bought a new Shigefusa santoku that's pretty rad that came with what appears to me to be a stone-finished zero grind. I don't know what kinda hardness they are running on their "swedish carbon ???" steel, but the edge is super thin and passes the nail flex test better than any other knife I have, actually. To my knowledge that speaks of a high hardness/strength to avoid rolling with good toughness as well. I have a HiSoft board and am just a home user, so the zero edge has held up great for me so far, as to be expected because the knife is only a few days old. Unfortunately the knife came OOB with a small chip on the edge, likely damaged in shipping somehow. It doesn't affect performance, so I'm gonna enjoy the knife for as long as I can without worrying about it.

I'm excited to try this style of sharpening when it comes time to! Always wanted to try a Watanabe too, been very interested for a while.


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## labor of love (Apr 12, 2019)

Yeah, as weird as it may seem the Mac Pro Suji I purchased a couple weeks ago can take and hold a very steep edge without chipping. Also sharpens super easy. I don’t think the grind is quite optimized ootb but if someone is feeling inclined to do some thinning it can keep up with much more expensive knives. I literally replaced my Marko suji with a Mac Pro and I feel pretty good about it.


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## inferno (Apr 12, 2019)

labor of love said:


> Yeah, as weird as it may seem the Mac Pro Suji I purchased a couple weeks ago can take and hold a very steep edge without chipping. Also sharpens super easy. I don’t think the grind is quite optimized ootb but if someone is feeling inclined to do some thinning it can keep up with much more expensive knives. I literally replaced my Marko suji with a Mac Pro and I feel pretty good about it.


aus-8 man, aus-8!


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## Cyrilix (Apr 12, 2019)

inferno said:


> I have a yoshikane skd11 hammered santoku. I sh1t you not when i tell you it takes a 12k shapton pro edge and gets so sharp its actually scary. And I'm used to sharp knives obviously. This is japanese D2, one of the very coarsest tool steels, with the biggest mutha F carbides ever in existence supposedly. But hey guess what? It takes a 12k edge  contrary to popular belief.
> 
> Vg10 is really not that bad imo. Its actally one of the better stainless steel overall. Yeah you will get 100 trillion reviews of vg10 chipping out and vg10 being hard to sharpen. And to be honest I have not found this to be true for my knives. But hey sh1t in sh1t out. you wanna pay 50 bux what you gonna expect?
> 
> ...



If skd can take a 12k edge, then so should many other steels.


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## inferno (Apr 12, 2019)

Cyrilix said:


> If skd can take a 12k edge, then so should many other steels.


correct.


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## merlijny2k (Apr 13, 2019)

U serious about the dropped hair split? I split a dropped potatoe and tomato, cleancut paper towel and sliced a tomato sideways without touching it, so i know my sharpening basics. Still a dropped hair seems like a longshot. Maybe a very long one. Or maybe my finisher just isn't good enough.


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## stringer (Apr 13, 2019)

I think it's possible. I have only taken it past 2k once. It was pretty unreal. I'll try it sometime.


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## Michi (Apr 13, 2019)

stringer said:


> I think it's possible. I have only taken it past 2k once. It was pretty unreal. I'll try it sometime.


It probably is possible. But also pointless, other than for amusement value. After half a dozen cuts, that edge will go back to a normal "very sharp". Good demonstration of this here:


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## stringer (Apr 13, 2019)

Michi said:


> It probably is possible. But also pointless, other than for amusement value. After half a dozen cuts, that edge will go back to a normal "very sharp". Good demonstration of this here:




There's a reason I don't keep anything finer than a 2k stone at work. Beyond that, to me, is pointless, for most food applications. But for $h¡+s and giggles sake.........


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## Luftmensch (Apr 13, 2019)

stringer said:


> The way I cut baguette there is plenty of board contact. And I meant 1/16 inch thick slices. That's probably an exaggeration, let's say 1/8 inch slices. On the bias. We toss them with olive oil and toast them to serve with cheese and charcuterie. Each loaf makes 25-30 slices. 96 loaves. Speed is of the essence. It's pretty tough on hard steel.



No! Seriously? In my language that is 3mm slices... If so... kudo sir!


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## Luftmensch (Apr 13, 2019)

K813zra said:


> Man, I miss that bread. Good stuff for some toasta catalana



Insane! I like a crusty bread but that sounds next level!


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## Luftmensch (Apr 13, 2019)

inferno said:


> Almost all vg10 knives are overheated from the factory on belt sanders so they have brittle edges. they basically re-austenitized them without tempering them. So you have to grind off 1mm or so and then its all good metal there. and you obviously know how to grind off some metal.



Interesting...

I had exactly the same thing with the ZDP. It micro chipped like crazy out the box. I figured the volume of metal at the edge was so thin it quenches the fastest and become brittle... or like you say, that similarly small volume overheads during grinding.

.... either way, a bit of thinning/sharpening got rid of it.


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## K813zra (Apr 13, 2019)

Luftmensch said:


> Insane! I like a crusty bread but that sounds next level!



I am exaggerating but the interesting thing is that not by much. The very outer layer of the crust is very, very hard. It really is good. It makes for great day old bread for crouton making. Not all of the bread was that hard but all of the bread in the bakeries was harder than the hardest stuff I can find here, which I really miss. Then again my apartment was above the bakery so I got fresh bread every morning.


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## stringer (Apr 13, 2019)

A note about terminology. Thinning and sharpening are never separate activities for me. When I first get a knife I establish a wide primary bevel. Depending on the geometry of the knife this bevel will be somewhere between 1/3 of the face of the knife and 100% of the face of the knife. For the life of the knife my goal will be to keep that geometry and profile for the life of the knife. That wide bevel will slowly move up the knife through that hamaguri sharpening or whatever like in Jon's videos. 
For most of the knife world a zero edge means a full flat grind that extends all the way to the edge. This is often called a scandi grind. 
When I say "reset back to the zero grind". I mean that I am resetting just that primary bevel, wherever it is for that particular knife. From there it will be a nice flat bevel to the edge and I get rid of any previous secondary micro bevels. Here's a picture I took for a different thread showing where my "primary" bevels are on different knives. The area beneath the sharpie line is my focus.
Once I raise a burr in the primary wide bevel, then I make adjustments as necessary with microbevels to increase durability/correct steering/prevent edge rolling, whatever. For thicker softer knives no adjustment is necessary.


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## LucasFur (Apr 13, 2019)

Best thread in a very long time for me. 

I have had the micro chipping experience with ultra thin edges but never saw them develop to what you have there. That's really awesome. 

Amazing to see you use these tools to their fullest! And actually talk to somebody putting them through 1000's of lbs of produce.


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## stringer (Apr 13, 2019)

This is my favorite test for checking for residual burr. Cut a circle in a piece of paper. If the knife can do this cleanly without tearing the paper, then you're good.


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## HRC_64 (Apr 13, 2019)

Looks great...nice work


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## stringer (Apr 25, 2019)

Watanabe Update
Today was the first day I busted her out since I made Bolognese a week or two ago.

I chopped another hundred pounds each of zucchini, yellow squash, and eggplant today. It's less volume than the other day, but it was added on to a lunch last minute, so I was in more of a hurry and probably more violent in my chopping.






Then I sliced 200 pounds each of cooked skirt steak and chicken breasts for fajitas. 






There's definitely micro chips. The micro bevel is about 45 degrees inclusive. It's probably slightly less than 1 mm wide on both sides. There are a couple chips that come about 1/3 up the microbevel. There are dozens in the .1-.2 mm range. These are barely visible. But you definitely hear them and feel them if you slice some paper. Most of the work was done with the middle 1/3 of the edge. So that's where the most damage is. 






I wasn't paying attention the other day when it was damaged pretty bad, but I would guess that I did this amount of damage in the first 15 or 20 minutes. And today I was using it for about 4 hours. So quite a bit more durable obviously. At this point any other knife I have owned would be quite dull. But probably wouldn't have any visible micro chips either.

The edge is still fine for cutting food. Most of the time at this point I would give the bevel a touch up on the 2k superstone. It would erase most of the smaller chips and leave some barely visible (although depending on what your doing, potentially annoying) little dings. 

This time I will hold off a week or two. For science's sake. I'm hella busy, so it will get some action.


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## ian (Apr 25, 2019)

Man, you make me want to come downtown and volunteer to chop some stuff for a few hours. I’m perpetually frustrated at the limited amount of stuff I get to use the knives on at home... Anyway, thanks for the updates.


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## Nemo (Apr 25, 2019)

Not sure if I missed it... what cutting surface are you using? Do you think that it makes much difference or is it just the volume of food you are cutting?


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## panda (Apr 25, 2019)

when you're doing that much volume technique pretty much gets thrown out the window. i would invest in a sani-tuff cutting board if you don't already have one. instead of using a microbevel, just increase the angle of your primary bevel. if thin behind the edge, you dont need a crazy low bevel angle.


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## stringer (Apr 25, 2019)

Nemo said:


> Not sure if I missed it... what cutting surface are you using? Do you think that it makes much difference or is it just the volume of food you are cutting?



I'm using the crappiest cutting boards imaginable. Color coded restaurant supply plastic boards. It's
huge volume. My technique is rather assertive. The fajita seasoning was pretty rough. I ground fresh peppercorns, coriander seeds, and cumin seeds. They were pretty fine, but there were still some chunks because I was in a hurry and couldn't find the spice grinder so I used a blender.


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## stringer (Apr 25, 2019)

panda said:


> instead of using a microbevel, just increase the angle of your primary bevel. if thin behind the edge, you dont need a crazy low bevel angle.



That makes sense. I'll try it.


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## panda (Apr 25, 2019)

stringer said:


> I'm using the crappiest cutting boards imaginable. Color coded restaurant supply plastic boards. It's
> huge volume. My technique is rather assertive. The fajita seasoning was pretty rough. I ground fresh peppercorns, coriander seeds, and cumin seeds. They were pretty fine, but there were still some chunks because I was in a hurry and couldn't find the spice grinder so I used a blender.


vitamix works better than spice grinder and you can do way more volume at a time. you just gotta increase the speed gently, and then take it off and shake and repeat process a few times.


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## stringer (Apr 25, 2019)

panda said:


> vitamix works better than spice grinder and you can do way more volume at a time. you just gotta increase the speed gently, and then take it off and shake and repeat process a few times.



That's what I did actually. Just didn't quite get it all ground. There were more chunks in there than I intended. I usually prefer a burr coffee grinder for the peppercorns but it was MIA.


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## refcast (Apr 25, 2019)

For the handle, if you don't like the stone grit/swarf stuck on it, you can take a little bit off by rubbing with oil and a cloth. Olive oil works fine, lighter oils remove it better. Microchipping -- yeah when that happens I agree make a higher angle bevel. You can blend it in a bit, if you want a smoother cutting feel. Blending it does take steel off though, which makes it a bit less tough. Do it enough and I would be basically thinning behind the edge.


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## Patrick Gilmartin (Apr 26, 2019)

stringer said:


> A note about terminology. Thinning and sharpening are never separate activities for me. When I first get a knife I establish a wide primary bevel. Depending on the geometry of the knife this bevel will be somewhere between 1/3 of the face of the knife and 100% of the face of the knife. For the life of the knife my goal will be to keep that geometry and profile for the life of the knife. That wide bevel will slowly move up the knife through that hamaguri sharpening or whatever like in Jon's videos.
> For most of the knife world a zero edge means a full flat grind that extends all the way to the edge. This is often called a scandi grind.
> When I say "reset back to the zero grind". I mean that I am resetting just that primary bevel, wherever it is for that particular knife. From there it will be a nice flat bevel to the edge and I get rid of any previous secondary micro bevels. Here's a picture I took for a different thread showing where my "primary" bevels are on different knives. The area beneath the sharpie line is my focus.
> Once I raise a burr in the primary wide bevel, then I make adjustments as necessary with microbevels to increase durability/correct steering/prevent edge rolling, whatever. For thicker softer knives no adjustment is necessary.
> ...


Interested in this technique. Also notice you from Boston too. If you ever want to host a demo....


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## inferno (Apr 26, 2019)

Really love your performance tests stringer! keep em coming.


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## stringer (Jul 31, 2019)

I haven't updated this one in awhile. Knife has seen a lot of use. I thickened my thinning bevel slightly and then did a .4 mm micro bevel at about 45 degrees inclusive. Very sturdy. I have only touched it up for months. It still doesn't really need sharpening but it's getting pretty funky patina and needs a cleanup. So I took care of that today with some sanding and then resharpened.


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## panda (Aug 1, 2019)

I love that this guy gives no f*CKS about how his knife looks just like me, hahaha.


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## labor of love (Aug 1, 2019)

I recognize that patina. Thats "blade stored in an edge guard/saya for 2 weeks without use" reactivity.


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## stringer (Aug 1, 2019)

panda said:


> I love that this guy gives no f*CKS about how his knife looks just like me, hahaha.



I'm working my way up the food chain. Wait until I get to the Shigefusa. A bunch of flippers will shart their drawers.


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## stringer (Aug 1, 2019)

labor of love said:


> I recognize that patina. Thats "blade stored in an edge guard/saya for 2 weeks without use" reactivity.



The rust color is mostly from one bad day about a week ago. I started a project and got called away. Came back a few hours later....


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## Cyrilix (Aug 1, 2019)

stringer said:


> I'm working my way up the food chain. Wait until I get to the Shigefusa. A bunch of flippers will shart their drawers.



I love your "just don't give a ****" style. Knives are tools and you're working them to the bone.


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## stringer (Aug 1, 2019)

stringer said:


> The rust color is mostly from one bad day about a week ago. I started a project and got called away. Came back a few hours later....



This blade actually has my favorite bespoke saya.


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## panda (Aug 1, 2019)

Don't bother, shig and kato are all hype, there are much better knives.


stringer said:


> I'm working my way up the food chain. Wait until I get to the Shigefusa. A bunch of flippers will shart their drawers.


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## daveb (Aug 1, 2019)

panda said:


> Don't bother, shig and kato are all hype, there are much better knives.



Damn, next you'll be saying the Emperor is nekid.


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## M1k3 (Aug 2, 2019)

stringer said:


> I'm working my way up the food chain. Wait until I get to the Shigefusa. A bunch of flippers will shart their drawers.



I love this guys gumption!


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## DitmasPork (Aug 2, 2019)

panda said:


> Don't bother, shig and kato are all hype, there are much better knives.



I like my Kato, wonderful knife. But at current prices, many Katos BST seem more aimed at serious collectors, or deep-pocketed cooks. Low scoring knife on the "bang-for-buck chart." Good to have if one can afford it.

My Marko workhorse, based on the Kato profile and grind is a better performer than my Kato WH, for about a third of the price in 52100, with a much better handle. Yes Katos have hype, mystique, etc.


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## Nemo (Aug 2, 2019)

panda said:


> Don't bother, shig and kato are all hype, there are much better knives.


Yeah, I'm glad I never got on the uber collectable knife train. I'm still busy exploring the wonderful world of performance variation in (relitavely) affordable knives.

I reckon if I spent over a thousand on a knife I might baby it, so probably wouldn't appreciate its full potential. I would probably also be too scared to maintain it properly.

Not what a knife is for IMO.


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## Customfan (Aug 2, 2019)

Nemo said:


> My 2 Bobs' (2 cents') worth:
> 
> Watanabe's blue2 is a pretty hard HT. Hard means it will hold a pretty acute edge without rolling over but will be prone to (micro)chips if the edge is too acute for the type of work you are doing. Another way of saying this is that the mode of failure of the edge will be chipping rather than rolling, even if this failure occurs at a higher threshold.
> 
> ...



+1 retention is up there...

Just makes me appreciate Watanabe's even more....

Great job bringing that blade back to life!

Thanks for sharing...


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## Thorndahl88 (Sep 19, 2019)

Great read. Thanks stringer ! 
I might try the zero grind on my toyama 240 its too fat.


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