Durability testing Watanabe Pro Gyuto

[stringer]

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:

 

[rickbern]

Fingers held up better than the steel; go flesh!

 

[inferno]

It happens. Not really surprising.

 

[inferno]

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

 

[refcast]

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

 

[stringer]

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

 

[stringer]

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.

 

[RDalman]

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.

 

[lemeneid]

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.

 

[stringer]

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.

 

[RDalman]

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

 

[MrHiggins]

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!

 

[stringer]

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.

 

[Gregmega]

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]

 

[Gregmega]

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

 

[stringer]

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.

 

[swarth]

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

 

[DitmasPork]

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

View attachment 51563 View attachment 51564

210 stainless petty/suji

View attachment 51565

View attachment 51566

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.

View attachment 51569
View attachment 51570

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.

 

[Gregmega]

Hahaha yes! Cliff bar saya!

 

[JBroida]

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

 

[panda]

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.

 

[stringer]

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.

 

[John N]

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

 

[merlijny2k]

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.

 

[inferno]

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.

 

[stringer]

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.

 

[Xenif]

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

 

[Ivan Hersh]

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

 

[stringer]

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.

 

[Nemo]

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.