# Oh #[email protected]% - Macro chip on a rather pricey knife



## Kippington

I think some of you guys might find this interesting.
So at work yesterday I was cutting a big wedge of Parmesan cheese in half when I hear a *_tink_* sound, aaaannnnddddd...






_(mildly interesting note: you can see micro and macro chipping in this image)_

Ohhhh man
The initial damage to it actually goes a few months back - I received the knife on my birthday and consequently cracked in the blade on the first day due to playing with my new toy while drunk (I'm sure I am not the only person that does that sort of thing on _*this*_ forum haha!)
The initial damage to the knife was the part of the chip that goes straight up, the curved part of the chip-out is where the lateral force pulled a good chunk out a few months later.






The knife is a Sukenari ZDP-189 Wa Gyuto 270mm at 66-67 HRC. The high hardness of this steel is gonna piss me off now that I gotta take a rather large bit of metal off the knife to remove the chip. I'll try to document my repair progress and post it here if anyone is interested.
Also, before I start repairs, I would happily oblige if anyone has a request for me to test the knife against something they think could potentially damage the edge. I have two of these ZDP-189 knives and they perform very well, so I'd be more then happy to run tests on the edge for you guys so that this thread doesn't give the wrong impression that the steel is too chippy or brittle.

Let me know!


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## chefcomesback

That knife looks quite thin to begin with , for tasks like cutting Parmesan cheese or tough tasks I use an old beater German knife ( a.k.a the kitchens knife at work) or cleaver , sorry to hear about the chip,with the hardness of the steel I recommend you sending it to pro sharpeners ( Jon or Dave) I had a zdp189 knife that had to be thinned , it was PITA, good luck


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## XooMG

Or if you repeat the process, in a few years you will have yourself a truly amazing bread knife.


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## dough

ya i would let someone with a belt fix that for me but im interested to see your work in progress and tools you use to work it over.
before the chip that looks like a great profile. when i first started reading i was thinking no way parm cheese did that but makes way more sense with a previous ding. anywho stuff happens and this will definitely test your resolve. mostly i appreciate you sharing the process


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## Fritzkrieg

I've always heard not to cut something called winter squash with J-Knives, maybe that would be a good test. Also frozen food.


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## ptolemy

sadly, I would also not cut cheese with anything over 61hrc


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## Kippington

dough said:


> ya i would let someone with a belt fix that for me but im interested to see your work in progress and tools you use to work it over.
> before the chip that looks like a great profile. when i first started reading i was thinking no way parm cheese did that but makes way more sense with a previous ding. anywho stuff happens and this will definitely test your resolve. mostly i appreciate you sharing the process



I do have a cheap belt grinder which I will be using for for a good amount of the work. I may as well get most of the job done quickly on the belts, then finish the finer details by hand.

And yeah, I'm pretty certain parmesan cheese would've done no damage to the blade if it was in perfect condition. A previous accidental encounter with concrete is what turned the odds vastly against it holding up to the hard cheese. :O
Funnily enough, my other ZDP gyuto (same knife but in 240mm) fell out of its "friction fit" saya as I was running across the road and hit the tarmac hard. Luckily and surprisingly, no damage to that one at all.
I might be wrong, but going off my experience using and sharpening these two knives I think one of them is at the higher end of the bladesmith's target hardness and the other is at the lower end (they're advertised at 66 to 67HRC). Testing will be done on the harder one of the two, assuming I'm correct.



Fritzkrieg said:


> I've always heard not to cut something called winter squash with J-Knives, maybe that would be a good test. Also frozen food.



I'm not sure about the availability of winter squash here in Australia, but I can definitely find some hard pumpkin. As for frozen food, I honestly can't even imagine a realistic scenario where I would want to do that. Can someone please suggest to me a food item to freeze then attempt to cut? All I can think of is frozen solid chicken thighs, which I already know I will have to resort to using the knife like an axe. Not pleasant.



ptolemy said:


> sadly, I would also not cut cheese with anything over 61hrc



I'll add cheese to the test list too. Although I already know it will pass that test as I've 'risked' hard cheese many times, and the only damage occurred on an already damaged spot. Even with the damaged spot it took many sessions of 'cheese abuse' for the cracked area to chip.


Already there have been some good ideas - keep the suggestions coming! I'll make a stress test video as soon as I can then I will begin repairs (assuming I don't end up snapping the knife! :bigeek: )


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## chefcomesback

Winter squash = japanese pumpkin
Butternut squash = butternut pumpkin in down under


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## WiscoNole

Yikes


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## Fritzkrieg

I can't think of anything that anyone would realistically cut while frozen. How about really crusty BBQ or hard bread?


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## Rayuela

Salo (Ukrainian pig fat - a bit like lardo) cuts when frozen.


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## mhlee

chefcomesback said:


> Winter squash = japanese pumpkin
> Butternut squash = butternut pumpkin in down under



I always use thinner knives for squash or pumpkins, like my 240 Gesshin Ginga. No problems.


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## aboynamedsuita

Kippington said:


> The knife is a Sukenari ZDP-189 Wa Gyuto 270mm at 66-67 HRC. The high hardness of this steel is gonna piss me off now that I gotta take a rather large bit of metal off the knife to remove the chip. I'll try to document my repair progress and post it here if anyone is interested.
> Also, before I start repairs, I would happily oblige if anyone has a request for me to test the knife against something they think could potentially damage the edge. I have two of these ZDP-189 knives and they perform very well, so I'd be more then happy to run tests on the edge for you guys so that this thread doesn't give the wrong impression that the steel is too chippy or brittle.
> 
> Let me know!



I have the exact same knife sans macro chip as well as the 240mm W#1 Honyaki gyuto. That's a bummer what happened (I remember the price tag). I've heard it said that Sukenari knives are thin behind the edge, and this supports that statement.

I'll be following this thread as I'm curious to see the progress of the repair.


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## Kippington

tjangula said:


> I have the exact same knife sans macro chip as well as the 240mm W#1 Honyaki gyuto. That's a bummer what happened (I remember the price tag). I've heard it said that Sukenari knives are thin behind the edge, and this supports that statement.
> 
> I'll be following this thread as I'm curious to see the progress of the repair.



Interesting, I never considered this knife to be that thin, but you're probably right. I guess it's all relative.





Left to right: Sukenari 240mm, Sukenari 270mm (w/ chip), Richmond GT Artifex 210mm (thinned).

And thanks for the info chefcomesback. It will help with the shopping.
I'll try to record a stress test video tonight.


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## aboynamedsuita

Kippington said:


> Interesting, I never considered this knife to be that thin, but you're probably right. I guess it's all relative.



To be honest I agree with you as I consider my Carter and Takamura knives thin. I know I didn't read that at KKF as there seems to be little info on the Honyaki/ZDP ones here. I like the Honyaki one I have but kind of wish I got the Masamoto HS-3124 instead, but it's been unavailable forever.


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## petefromNY

that gonna be one hell of a job


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## marc4pt0

This happened to me last year, while halving acorn squash. About six in when I noticed three decent _ chunks_ missing from the edge. I went back through the squash, found the "missing pieces" and discarded the squash just to be safe. I was a little pissed but took it in stride and spent a couple days re-grinding and re-profiling the knife. The heel lost about 1.5mm and the belly lost about 3mm +/-. But I was able to maintain the profile of the tip (to about 70mm in). It took some work, but a great learning experience all around.

I also learned that round chips, like the ones in this pic, are a sign of the knife not being _ over hardened_, whereas sharp chips may be a sign to the contrary.


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## toddnmd

Marc, what knife/maker/steel/HRC was that knife? What do people use for such jobs?


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## Mangelwurzel

Kato?


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## Mangelwurzel

mhlee said:


> I always use thinner knives for squash or pumpkins, like my 240 Gesshin Ginga. No problems.



+1. I love how the Ginga slides through butternut squash.


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## chefcomesback

mhlee said:


> I always use thinner knives for squash or pumpkins, like my 240 Gesshin Ginga. No problems.



Sorry I didn't elaborate enough, thin and very hard was what I wanted to say .


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## chefcomesback

That is his Kato western I believe


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## TheDispossessed

sadness


marc4pt0 said:


> This happened to me last year, while halving acorn squash. About six in when I noticed three decent _ chunks_ missing from the edge. I went back through the squash, found the "missing pieces" and discarded the squash just to be safe. I was a little pissed but took it in stride and spent a couple days re-grinding and re-profiling the knife. The heel lost about 1.5mm and the belly lost about 3mm +/-. But I was able to maintain the profile of the tip (to about 70mm in). It took some work, but a great learning experience all around.
> 
> I also learned that round chips, like the ones in this pic, are a sign of the knife not being _ over hardened_, whereas sharp chips may be a sign to the contrary.


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## TheDispossessed

well,
if you're in the shits in a pro kitchen, there can be a lot of things you have to cut while half frozen because you or someone else did not thaw it and now theres no time.


Fritzkrieg said:


> I can't think of anything that anyone would realistically cut while frozen. How about really crusty BBQ or hard bread?


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## Dardeau

I use a mallet and and the boss's knife.


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## marc4pt0

Dardeau said:


> I use a mallet and and the boss's knife.



I actually laughed out when I read this. Haha!


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## marc4pt0

toddnmd said:


> Marc, what knife/maker/steel/HRC was that knife? What do people use for such jobs?




Kato Western handle Workhorse. It was pretty thin behind the edge. But after fixing it, nothing got in it's way. One of those serendipitous kind of sufferings if you will.


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## Dardeau

I should take a picture of his knife for yall. It is a hattori forum with what may be best described as a whimsical sharpening job. In reality we keep a Henckles around for the mallet jobs.


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## Kippington

I just got home from work and I'm too tired to edit a proper video from the footage I've recorded today.

Here's an unedited teaser for what I've got in store. I'll do some proper editing tomorrow.
[video=youtube;1efKHUpCGQA]https://www.youtube.com/watch?v=1efKHUpCGQA&feature=youtu.be[/video]


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## Dardeau

Dang. I imagine that felt kinda good


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## Kippington

Dardeau said:


> Dang. I imagine that felt kinda good



Yea it feels kinda like gambling haha

While I'm doing this I'm placing a lot of faith in the maker of this knife, his heat treatment methods, his choice of steel, even my own sharpening abilities to a small degree. But despite all this, there's always that small moment of fear as the blade hits that I've made the wrong bet...


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## chefcomesback

You said you have a belt grinder , be careful not to overheat the blade especially near the edge during repair . If you don't have variable speed control you will only have split second on each pass before it turns blue ( blue = bad , very bad)


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## rami_m

Can I suggest trying frozen cheese cake?


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## CutFingers

Do not use a belt grinder at all. Consider it a lesson in humility. You abused the knife, now endure the abuse of repairing the chip. You are going to lose blade height. There is no way around it.


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## Kippington

If you are offended with what I'm doing to the knife in this thread, I respect your opinion and understand your attitude.

However...


CutFingers said:


> You are going to lose blade height. There is no way around it.


Repeating this information back to me like its something I wasn't aware of tells me you haven't read or understood the first page and first post of the thread.


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## Kippington

I have a new video uploading now. It will feature a 4.3kg wedge from a wheel of parmesan cheese.

I'll have a link ready when I get back from work tonight.


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## Dardeau

Short derail...
The boss's knife



He's good at many things, but sharpening isn't one of them.


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## Sabaki

looking at the content of the steel ZDP-189 it's very understandable it can't hold a thin edge very good... 3% carbon:bigeek: and 20% Chromium a little Molybden Wolfram and a tiny pinch of Vanadium of only 0.10% makes the grain size in that steel HUMUNGUS :scared4:

Heat treating such blade before hardening is very important and it might have worked better with a high temp tempering of 500-530Celsius 3x1hour after heat treat due to high Chromium, Molybden and Wolfram content. it would loose some of it's rust inertia tho, a little late for that now


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## Lizzardborn

Dardeau said:


> Short derail...
> The boss's knife
> View attachment 26812
> 
> He's good at many things, but sharpening isn't one of them.



That looks like k-tip in reverse ...


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## Kippington

ptolemy said:


> sadly, I would also not cut cheese with anything over 61hrc


This one's for you!

Parmesan cheese with a 67HRC knife

[video=youtube;bXT9yAPVtac]https://www.youtube.com/watch?v=bXT9yAPVtac[/video]

I'll post more soon.


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## marc4pt0

It makes me cringe when I see people cutting cheese without a folded towel over the tip. 
Other than that, keep the videos coming!


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## Kippington

Yeah I needed the folded towel at one stage, but the rest of the time I felt it wasn't a necessity.
270mm makes for a huge surface area to push down on before slippage at the tip becomes an issue. Any smaller and I would've been toweled up for much more of the vid.


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## Keith Sinclair

As you well know some jobs in a kitchen put more stress on a knife. I prefer to save my hard thin edge blades for the type of prep. that does not stress the edge. Cutting big wheels of cheese chance of slight torque on blade which can damage it.

Why don't you get a less expensive 270mm 57-60 hrt. for the grunt work.

Good luck on your repair. With an expensive blade like that I would dip it in a bucket of H2O every couple passes you do not want that edge to overheat at all on a belt sander. You probably know this, but thought I would mention it anyway.


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## Dardeau

I have a coworker that cut halfway through his left wrist like that. I've never seen so much blood in my life. We bought a two handled dexter cheese knife after that, but he referred to the footlong bullnose that cut him as Lord Voldemort and claimed it made his scar hurt to use it or have it on or near his station.


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## aboynamedsuita

Kippington said:


> Yeah I needed the folded towel at one stage, but the rest of the time I felt it wasn't a necessity.
> 270mm makes for a huge surface area to push down on before slippage at the tip becomes an issue. Any smaller and I would've been toweled up for much more of the vid.



I meant to ask you earlier... How'd you find the F&F on that knife? Mine was decent but there were some small areas where the mirror polishing could have been a bit better. Also a couple scratches on the blade near the tip on one side just above the bevel which didn't really need to be there, they must have tried sharpening it at the factory with a really low angle. Not too big a deal but something you notice when you pay for a product in that price range.


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## Mrmnms

I get queasy when I check this out . Each to his own, but I keep thinking to myself, " I bet I could really til my buddies field up with my Audi convertible if I wanted, but I'm sure his tractor is better suited to the task."


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## Kippington

Dardeau and marc4pt0, I'm not going to forget that story in a long time. Thanks for the warning, I will consider toweling up more often.

keithsaltydog and chefcomesback, thank you both for reminding me of the importance of proper temperature control during high speed grinding tasks. As you've guessed, I was already aware of this and this won't be the first time I have used the belt grinder to modify one of my ZDP knives, after breaking the tip off one of them.

Which brings me to tjangula's question.

I honestly don't have much experience with knives around this price range so I consider the F&F to be fine for what I use them for. I'm not a picky person, but if I was to _really _try to find issues with the finish, they would be:

- The ZDP logo on one of them has been stamped in slightly lopsided.
- The shape of the tip isn't the best. I had to regrind the tip of one of mine after it snapped off (I dropped it into the dish-sink while washing it), and I like my work on the tip much better then how they came brand new.
- There seem to be some impurities forged into one of the blades in a couple of places. Even taking the surface metal off the offending area won't remove these marks.





_My repaired tip on the left and the factory tip on the right. Notice the impurities in the right blade: they don't scratch off._

I personally have no problems with the mirror polish on either blade, but TBH that kind of thing isn't high up on my list of important features.



Mrmnms said:


> I get queasy when I check this out . Each to his own, but I keep thinking to myself, " I bet I could really til my buddies field up with my Audi convertible if I wanted, but I'm sure his tractor is better suited to the task."



I guess this is the point: To show that these knives are not as brittle or fragile as many people think.
But hey, my next video will be showing how I normally use these knives every day. Just so people don't think that these tests are why I bought these nice knives in the first place.


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## Kippington

Here we go: A video showing a more 'run of the mill' use with one of these knives.

Shout out to Theory, Salty, CGuarin and everyone else that has done similar videos. I wanted to see how much work was involved in making one and its more then I care to do often, for the time being anyway.

Hope you enjoy.

[video=youtube;HrQYDM4QKK0]https://www.youtube.com/watch?v=HrQYDM4QKK0[/video]


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## chinacats

Nice video, thanks for the effort!


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## Keith Sinclair

I know your blade is sharp with the fine red pepper cuts with skin side up.


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## Kippington

Thanks for the kind words guys.

I'll do pumpkin and something frozen in the next couple of days then get started on the repairs.


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## Mrmnms

I feel better now,


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## Fritzkrieg

Kippington said:


> Thanks for the kind words guys.
> 
> I'll do pumpkin and something frozen in the next couple of days then get started on the repairs.



Sweet, looking forward to that!


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## Godslayer

Kippington said:


> This one's for you!
> 
> Parmesan cheese with a 67HRC knife
> 
> [video=youtube;bXT9yAPVtac]https://www.youtube.com/watch?v=bXT9yAPVtac[/video]
> 
> I'll post more soon.



This hurt me, poor knife.


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## Kippington

Ok here we go.
There was a birthday drinking session going on in the back during the recording. It's a typical Aussie Sunday night, so apologies in advance for the language. I could've muted the audio but I wanted to keep the sound of the knife hitting stuff in the video.

[video=youtube;Nusg5fxVbuM]https://www.youtube.com/watch?v=Nusg5fxVbuM[/video]

After making pumpkin soup, I was getting pretty drunk and decided to go all medieval on the edge. To you guys that thought the cheese vid was bad, you'll love this one.

[video=youtube;17FPrWiXkf0]https://www.youtube.com/watch?v=17FPrWiXkf0[/video]

Sorry for not doing anything frozen, but there's nothing suitable in the freezer and I'm too lazy to go out and buy anything.
I think I will start repairs today.


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## AllanP

lol jesus christ


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## Kippington

So in conclusion:
The damage to the edge was only minor throughout the entire experiment.
The pumpkin/squash and the cheese did insignificant damage to the cutting edge. You would need a microscope to see the differences before and after, and the edge retention was great. I honestly think more damage was done hitting the cutting board at the end of each cut, rather then cutting the hard foodstuff. In the pumpkin video I try to put a lot of lateral force into the knife with a lot of twisting at the same time as pulling/pushing on the blade (see 0:54 into the vid and you can hear it). I was hoping for some chip out, similar to what happened in the first post of the thread, but nothing happened.

Thrusting the tip of the knife into a metal lid was surprising - I was prepared for some serious damage but the blade held up fine.

Smacking the knife into the bone did the most damage of all the tests in the form of slight micro chipping and rather surprisingly, minor edge misalignment. I didn't expect an edge hardened to 66-67 HRC to bend just as much as it chipped.
But even then, the damage is so minor that it doesn't really show up on the video, and any of us could repair the edge in one average sharpening session.

Overall I'm very happy with how the edge held up. It's much tougher then I thought, and during the repair I might even thin the blade a bit more then it came OOTB as I think it should be able to handle it. But that's one of the many topics I'll be thinking about during the second half of this thread: Repairs and its effects on edge geometry.


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## Bolek

This damaged knife seams extraordinary as it is. Have you consider not repair it? Then youll get a parmesan and pumpkin proof 67HCR knife. On your video I cannot see any functional problem with the chip. And youll save 1.5 to 3 mm ZDP189 and a bunch of time.


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## aboynamedsuita

Thanks for doing this thread, it makes me appreciate my knife even more now (it's going to get a rehandle)


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## tcmx3

ZDP might take a high hardness but doesnt it have a lot of toughness for those hardnesses, relatively speaking?

Rockstead's trade show guy does bamboo chopping demonstrations with the stuff though being a pocket knife the thickness is significantly higher. Still, I've always liked ZDP from a pocket knife standpoint; it's just hard to find.


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## Kippington

tjangula said:


> Thanks for doing this thread, it makes me appreciate my knife even more now (it's going to get a rehandle)


Glad to hear it, I love these knives too!

Only a fortnight after receiving my first ZDP 240mm, I enjoyed it so much I went ahead and ordered the 270mm. I figured that even though I didn't really need another gyuto, Sukenari deserved my support for using a PM steel that isn't so popular anymore and heat treating it to its maximum hardness (everyone else making ZDP gyutos seem to dial down the HRC by a few points).
Who are you going to get to rehandle your knife? And please post pics or PM me when you get it back, I'd love to see what you have done to it!



Bolek said:


> This damaged knife seams extraordinary as it is. Have you consider not repair it? Then youll get a parmesan and pumpkin proof 67HCR knife. On your video I cannot see any functional problem with the chip. And youll save 1.5 to 3 mm ZDP189 and a bunch of time.



You are correct about there being no problem when cutting pumpkin and parmesan, but with a chip there I can't use it in the same way I use the other ZDP knife in the escabeche video.
Even cutting through the parmesan, I can feel the drag on the chipped part of the blade as it forces itself through. Not the nicest feeling I admit, but it was worth it for these videos alone.
And anyway, I'm looking forward to fixing it. I would like to change a few things about it, such as the profile and thickness, and the whole experience should be a great learning tool for myself and a few others here.
Maybe I'll turn it into a sujihiki or even a double-beveled kiritsuke ! :eek2:


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## aaamax

The feeling was probably akin to what I felt when "someone" used my 270 Shig to chop almonds a nice little knot in your gut Learn to embrace the flea bites young grasshopper.


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## Keith Sinclair

If it were my knife would take no more than half the chip depth out. That way edge still below Damascus. With that much done regular sharpening will in time take it down more. You are not doing major surgery taking too much steel off the knife.

In a production kitchen knives do wear down but no need to hurry the process. It looks to be a good cutter as it is.


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## aboynamedsuita

Kippington said:


> Glad to hear it, I love these knives too!
> 
> Only a fortnight after receiving my first ZDP 240mm, I enjoyed it so much I went ahead and ordered the 270mm. I figured that even though I didn't really need another gyuto, Sukenari deserved my support for using a PM steel that isn't so popular anymore and heat treating it to its maximum hardness (everyone else making ZDP gyutos seem to dial down the HRC by a few points).
> Who are you going to get to rehandle your knife? And please post pics or PM me when you get it back, I'd love to see what you have done to it!



I've been in discussion with one of the vendors here. I'll PM you as I'm not 100% sure if it would be considered "advertising". And yes there will be pictures at some point.


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## Kippington

Thanks for the PM tjangula, I've messaged you back.

-------------------------------

So at the moment I'm most of the way through repairs on the knife, and as promised I'll share it here for anyone that's interested.

Before I got started I had some serious thinking to do about how I would approach the problem of removing the chip. One option was to thin the knife from either side until I removed the chip, and the other option was to 'bread knife' the cutting edge into the shape that I wanted and then thin the knife from there. I decided on the bread-knife option as I felt I would have the most control over the overall shape that way.
So I started by comparing the two knives I have; the 240mm who's belly I adore and the 270mm which has more of a flat spot (which I wanted to get rid of).












I took a thin marker and drew the new edge onto the 270mm in a way that it would have less of a flat spot. It's not so obvious in this picture, but later you can see the flat spot will become less pronounced.
I also made sure to draw this line below the level of the chip because I wanted an allowance for mistakes and to help make thinning the knife easier later on.

-------------------------------






So here is the knife after using a belt grinder to bread-knife the edge away. Notice the chip is still slightly visible (and will be for the rest of this post). Also the tip of the knife has been modified by bringing the drop point up a little and have the tip higher up on the knife then it was before. This is because the knife started to look a bit weird and misshaped after I had removed a few millimeters off the entire cutting edge.
Notice that the core layer is now covered by the cladding in some spots.

-------------------------------






Choil shot after bread-knifing. At this point I noticed that the blade is slightly warped down its length, and I spent a few minutes trying my best to bend it back into a straight line (see choil shot a few pictures below for comparison).

-------------------------------






Here is the knife after using a 80 grit high speed belt. I'm very grateful that I have this cheap grinder because it got days of potential elbow grease done in a few short hours. I over-heated some minor areas on the edge :shocked3: The thinner the edge gets, the faster it overheats!
I used the grinder to do as much work as I could safely manage before switching to the trusty stones.

-------------------------------






So this is how the knife currently looks... for now. This is straight off the belt and onto a cheap silicon carbide stone for half an hour or so. I'm very pleased with how the cladding has moved up the blade and exposed a good amount of the ZDP core: There was always a small chance that the core wasn't centered in the middle of the san-mai construction, and the end result could come out looking a bit off... but no such issues!
It hasn't been sharpened yet so it's completely blunt, however I've removed most of the bread knifing and it's very close to a zero grind, so sharpening will be easy when the time comes. But before then...

-------------------------------











I think the tip and the heel need a bit more work. They are notoriously difficult to finish accurately on a high speed belt without screwing something up. Maybe I need to learn/practice it as an advanced skill, but for now I'd rather use the slower hand method, especially on such an expensive knife.
Also the knife in it's current state is completely unpolished. That will come next when I'm happy with the tip and heel. Lastly will be the sharpening, which should get rid of any overheated spots as well as the last remaining part of the chip that I left there.

So far I'm very happy with how it's turning out. Let me know what you guys think and feel free to ask me any questions!


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## icanhaschzbrgr

Looks good so far, although I didn't understood why you haven't removed that chip completely using grinder.


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## Dardeau

I would guess it is because he's planning to remove some of the fatigued steel at the edge with stones, saving a little bit of height.


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## Zwiefel

Kippington said:


>



Congratulations on the worst choil shot ever!



Dardeau said:


> I would guess it is because he's planning to remove some of the fatigued steel at the edge with stones, saving a little bit of height.



Exactly what I thought.


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## Kippington

icanhaschzbrgr said:


> Looks good so far, although I didn't understood why you haven't removed that chip completely using grinder.



Sorry, I should've been clearer in the original post.

Ultimately when anyone approaches a job like this or anything all the way through to basic sharpening, we need to remove steel to improve the blade as much as we can while simultaneously removing as little as we can.
During the thinning process I'm aiming to get the knife down to a zero grind. then bring the edge back a bit with a secondary bevel and any subsequent sharpenings. Zero grinding makes the whole job take a bit longer then it need be, but I prefer to do it this way for a few reasons:
- Zero grinds are awesome to start with. When the secondary bevel is so small that it doesn't cause any noticeable wedging, the knife is so much fun to use!:lol2:
- As the grind gets ever closer to theoretical zero, I begin to see any minor flaws down the cutting edge (e.g. over-grind on one side) which I can correct as I go. 






- The grinder I use has one speed only, and it's damn fast. A 585mm belt length going at +2,000 RPM will tear chunks of steel off the knife if I hold it the wrong way for only half a second. Couple that with trying to get the knife edge as thin as you can and you have a very delicate edge which is even easier to damage quickly. Having some extra metal there which I plan on removing later is a kind of an insurance policy which allows for some sloppy mistakes.






- There's also the problem with heat management. As the metal gets thinner, it becomes much harder to keep cool. There were a couple of very small areas which I accidentally allowed to over-heat, but they will get removed once I start pulling more metal off the edge when I begin on the secondary bevel (you cant see the burns in the pics but I know they are there, they go the same distance into the blade as the chip currently does.)






So Dardeau was bang on the money when he said I was "planning to remove some of the fatigued steel at the edge with stones, saving a little bit of height."
You can even see it pretty clearly in this picture; the detailed shot of the tip. The knife looks kinda strange without any secondary bevel, but I need to allow extra space to add one in the near future.








Zwiefel said:


> Congratulations on the worst choil shot ever!



I should've attached a NSFW warning, or at the very least got you to sit down first...
It's like a KKF nightmare! :eek2:


----------



## tcmx3

strong work though.


----------



## rami_m

Zwiefel said:


> Congratulations on the worst choil shot ever!



Can you please elaborate a little? the image is a little fuzzy and I can't tell what's up?


----------



## tcmx3

rami_m said:


> Can you please elaborate a little? the image is a little fuzzy and I can't tell what's up?



there is no edge; the steel goes straight across to join the two sides instead of terminating in a point.


----------



## Kippington

Hey guys, I'll post the finished knife now that I'm happy with it. I'll continue from where I left off.

I got the cross-sectional geometry where I wanted with a course stone and a bit of elbow grease, working mostly the heel and the tip (the rest was done with the grinder earlier).






It's quite thin behind the edge, but after doing those tests earlier in the thread I'm thinking the knife can take this kind of angle.

Now that I was happy with the overall shape, all I had to do was polish and sharpen the thing. Here's a a picture of what the surface looked like during hand sanding the surface (80>120>360>600>800>1600 grit wet/dry)






Then after that I went out and bought a bunch of polishing compounds and buffing wheels that I could attach to my grinder.






Man the buffing wheels do a sweet job, but unfortunately the finish doesn't look much like the original. Here's the comparison shot with the 240mm version.






And yea I've sharpened the 270mm in that picture. That big ol' chip has _almost_ completely disappeared, along with any fatigued spots along the edge.
I don't think I'll bother trying to replicate the original damascus finish. I think I'd have to go out and buy a bunch of stuff to even attempt to copy it, and even then there's no guarantee that it will look the same. 
Besides... it looks pretty good in it's current state. :biggrin:

So that's it I guess. I'll take it to work in a couple of days and use it for prep and service. That will be an interesting time for me as I think I've done some pretty heavy work on the knife.

This is the first time I've done such a big job on a knife and I think it's turned out really well!
Once again, any criticisms or questions are welcome. Let me know what you think!


----------



## chinacats

Wow, looks great! Wonder if an etch would bring back what you're missing from the original?


----------



## Kippington

Thanks! Yeah I was thinking that too, but there's also a lot more depth to the grooves. It's like they used a buffing wheel with a course compound for ages before moving on to the finer grits.
I was thinking of buying some of that etching chemical. What was it called again, and how much does it cost?


----------



## James

ferric chloride and it's pretty cheap.


----------



## Kippington

James said:


> ferric chloride and it's pretty cheap.



Ah sweet, thanks.
I'll try to get some when I get a bit of free time and apply it to the blade... see what happens.


----------



## Ruso

Looking good. Nice job.


----------



## Zwiefel

Fantastic work! Now I feel like a slacker for my poor progress on a simple thinning project....


----------



## aboynamedsuita

Well done


----------



## wind88

Wow, two beauties. Does the ZDP steel get chippy during normal use (i.e. not hacking through bones or coconuts)?


----------



## CompE

How does it cut after your repair? Wedging? Food release?


----------



## Kippington

Thanks guys!
Some good questions...


wind88 said:


> Does the ZDP steel get chippy during normal use (i.e. not hacking through bones or coconuts)?



When I first got these ZDP knives they would micro-chip like crazy, so I changed the sharpening angle on them slightly to help alleviate the problem. The micro chipping then stopped, but to be honest I'm not sure if that was due to the change in angles or the removal of a fatigued edge. I get the feeling it was the latter.



CompE said:


> How does it cut after your repair? Wedging? Food release?



This is a hard one to answer. When I sharpened this knife I had meat carving in mind because 270mm has turned out to be too long and unwieldy for me as an all-rounder kitchen knife. As you can imagine I've taken it to work and been very happy with it as it has no issues with wedging or food release on a cooked piece of meat!
I've read a lot about stickage and food release on these forums, and it's kind of an interesting side topic for me. Sure I understand that some cutting jobs can be hugely affected by stickage, but as it turns out none of the cutting jobs I have to do at work (for the current menu) would benefit from even the most non-stick convex grind out there. Depending on the food I'm cutting, I'll either get insane amounts of stickage that can't be avoided (only ignored or worked around), or no stickage at all (such as meats and the like).

That being said, I'm happy to record some videos putting it through some more tests in the interests of learning!
I'll try chopping a raw potato to test for stickage as soon as I get some free time. Feel free to let me know any more ideas for these post-sharpening tests!


----------



## Adrian

Thanks for taking the time to post the photos. Very useful sequence and explanations.


----------



## Lovelynella

I must thank you greatly for posting your progress! You did a wonderful job and answered some of my concerns that I had with these ZDP knives.

I want to purchase my first Japanese knife, and don't want to double dip at high prices so I wanted to get something beautiful exactly like the 240 or 270mm version you have. 

I'm worried now after you mentioned microchipping that I may just destroy this knife during every day use and more importantly during sharpening. Would you recommend I stay away from these high HRC rated steels entirely, or can I learn to minimize damage, and more importantly is it worth putting up with a delicate knife to begin with? My current plan would have 2 different size gyuto's, 210-270, so I can protect my shiny baby as much as I can. However, my rational side says that's not efficient and I should get 1 that lasts and not be caught up with looks (Cater KU gyuto).


----------



## aboynamedsuita

Lovelynella said:


> I must thank you greatly for posting your progress! You did a wonderful job and answered some of my concerns that I had with these ZDP knives.
> 
> I want to purchase my first Japanese knife, and don't want to double dip at high prices so I wanted to get something beautiful exactly like the 240 or 270mm version you have.
> 
> I'm worried now after you mentioned microchipping that I may just destroy this knife during every day use and more importantly during sharpening. Would you recommend I stay away from these high HRC rated steels entirely, or can I learn to minimize damage, and more importantly is it worth putting up with a delicate knife to begin with? My current plan would have 2 different size gyuto's, 210-270, so I can protect my shiny baby as much as I can. However, my rational side says that's not efficient and I should get 1 that lasts and not be caught up with looks (Cater KU gyuto).



Welcome, not sure if you saw the earlier videos of what the Sukenari knife was subjected to but it appears quite robust; I know I'd never use mine like that. I have Carter stainless clad so not the KU but seeing them side by side with the Sukenari, I'd be more worried about damaging the Carter as they are much thinner. With KU you also have the reactivity


----------



## _PixelNinja

That's some nice work done on that blade. Well done!


----------



## Lovelynella

tjangula said:


> Welcome, not sure if you saw the earlier videos of what the Sukenari knife was subjected to but it appears quite robust; I know I'd never use mine like that. I have Carter stainless clad so not the KU but seeing them side by side with the Sukenari, I'd be more worried about damaging the Carter as they are much thinner. With KU you also have the reactivity



Thank you for the reply. I went back and was shocked at the videos. I was cringing with fear and excitement each time the blade was smacked hard into the board with the bone. This thread alone is my first resource as to why I want that Sukenari knife. I cannot believe how well he salvaged his blade, and the video showing him make the fish dish was beautiful.


----------



## Guss2

Very nice work, congrats on your new knife. Gary


----------



## Kippington

CompE said:


> How does it cut after your repair? Wedging? Food release?



Yay! New video! 

Sorry this took so long to record/post, I've been really busy at work as of late.
The first thing I do is test for steer on a carrot by running the knife down the length of it with very little pressure on the handle, basically encouraging it to travel in any direction it wants . It steers ever so slightly to the left. It would be an easy fix, but I don't feel the need to do it.

I didn't have any good ideas for stickage testing, so I cut up some spuds at different sizes and ended up boiling them for a mash. I actually learned a few things about stickage doing it this way but as I've mentioned before, it isn't too much of a big deal for me at work so I'm not going to over-think the results.

There was also one point where wedging was a problem but it seemed to happen to just one of the potatoes in particular. The rest seemed fine.

[video=youtube;L9n-GQTj-zM]https://www.youtube.com/watch?v=L9n-GQTj-zM[/video]

Thanks for all the kind comments in this thread that I didn't get to reply to. Reading them really helps to get me off my backside to record stuff! :biggrin:


----------



## Kippington

Hah so I've sobered up from last night's drinks and I have a few rambling thoughts to get out there.
But first I should apologize for a video that is 10 times longer then it needed to be. This was the first time I've done this kind of test and I got a little carried away! :laugh:

So considering stickage wasn't something I was thinking about when I re-profiled the knife, I think I did okay. It seems to go through a whole potato fine but starts sticking during the smaller slices.
One thing I regret not doing is testing it against the un-modified grind of the 240mm Sukenari which was sitting right next to me.

The tests brought up a few questions in my head too that maybe some of you can answer.

How thin can a knife be before it starts to become impossible to stop stickage (or whats the thinnest knife you have that you use on sticky foods)? The height of the knife would also come into play here. Also what foodstuff you decide to test-cut on, which brings me to another question...

What is your opinion on what an acceptable amount of stickage is? I mean there are foods that will always stick, no matter what. So what is the point at which you stop worrying about it? Potatoes _seem _to be the benchmark, but slicing potatoes in a way I've never needed as part of a dish before felt kinda strange... and yet at the same time I test cut paper for sharpness and smoothness on kitchen knives, and that's something I'll never need in a dish! :nah:

I'm going to leave this 270mm Sukenari as it is, but even so I'd like to learn a bit more for future reference.
I'd love to hear what you guys have to say about this!


----------



## Kippington

Oh and also, how much of this is in the cutting motion and technique? I noticed while cutting the tomato for example, changing my speed and motion (among other things) would yield different results in stickage.
Should I change my style rather then change the knife? :what:


----------



## Lovelynella

I dont know anything about 'stickage' when referring to knife performance. 

But I wanted to critique your latest video.

It was great because of the amount of cutting you did, the music, and the sound of the knife hitting the board. My only recommendation is that you keep with the theme of your previous videos, knife abuse, and cut these vegetables on an anvil so we can hear the beautiful d i n g !


----------



## Kippington

Ah that time of wrecking the edge is behind me now nella. I'm verry happy with the knife as it is so I don't want to have to do any more work on it. Not to mention I already did those tests to see how the steel would hold up to abuse, it should behave no differently now that I've taken the chip out.

Stickage, by the way, is the tendency for the food you cut to stick to the side of the blade, which is a bad thing. The whole last video was testing for that and the results were so-so. It doesn't bother me much but I would like to learn more if possible for next time. Unfortunately I'm getting a lot of thread views but not getting much help yet. Maybe it's more of a opinionated topic, or one which not enough people have experience to talk about it.

Either way I'll keep trying to learn one way or another.


----------



## mhpr262

That is a great job you did, it looks just as good as it came from the factory. It would have been a deeply traumatic experience for me to damage a brand new knife, and such an expensive one at that, on my first day of ownership and then have to remove so much metal. 

Good decision not to thin the tip and heels with the belt sander, I also have a cheap non-adjustable one and I have watched the tips of two knives turn red-hot, then dissolve in a shower of sparks in a fraction of a second so far ... thankfully it was just a $3 WalMart practice knife and a sh!tty $16 no-name gyuto ...


----------



## Kippington

mhpr262 said:


> Good decision not to thin the tip and heels with the belt sander, I also have a cheap non-adjustable one and I have watched the tips of two knives turn red-hot, then dissolve in a shower of sparks in a fraction of a second so far ... thankfully it was just a $3 WalMart practice knife and a sh!tty $16 no-name gyuto ...



Yea those cheap knives are a godsend to practice on! You can learn so much by messing around on an otherwise useless knife.


----------



## cheflarge

Looks like " Oh #[email protected]% - Macro chip on a rather pricey knife" repair was successful! Great job. As far as "stickage", etc. goes, in my opinion, just about all of the aforementioned can be influenced by technique, angel, speed. In the end I think whatever works best for you is the thing to go with. :cool2:


----------



## toddnmd

I remember reading through parts of this thread when it first came out. I just rediscovered it with renewed appreciation, and enjoyed seeing the extent of testing (particularly hacking at the chicken bone!). Danny's "worst choil" shot ever comment also gave me a smile.
Kippington, I was wondering if you have any updates after over a year of use. How is the blade holding up? I was also wondering if you primarily use it on a bamboo or poly board, or something more forgiving.


----------



## LifeByA1000Cuts

BTW, liked the request for unsafe things to try on a damaged-anyway blade ... permanent thread for that kind of "test market" might be an idea?

...

There are indeed a few things I like to chop frozen (that is what cheap Thai cleavers are great for, would never think of using a PM knife to do that!), frozen grated coconut (so much better than the dry sawdust, but usually you need to portion it and chop it down finer) is one of them... and certain aromatics that are hard to get at times - galangal, fresh turmeric come to mind. Can semi-thaw them to chop though, but portioning can be nasty, you rue the day when you just tiredly dumped the remainder of the asian grocery bag in the freezer after taking out anything that needs room temperature or fridge storage... 

I might be in the market for some really mean D2 yo-deba one day


----------



## Kippington

The knife from this thread hasn't changed much over the last year... What _has_ changed was the realization that modifying an expensive knife shouldn't be a major push out of your comfort zone. Instead it should be an understanding of what you like about an existing blade, and the willingness to change what you don't like - No matter how much money you spent on it! :laugh:

I'll try to update this as soon as I have the time (sometime in the next couple of days), and the major effect it's had on how I take care of my other knives.


----------



## jessf

Has the understanding of stickage evolved?


----------



## Kippington

I find that thin slices of a non-rigid foodstuff that isn't dry will pretty much always stick. Seeing that this is all I seem to cut, I don't pay much attention to stickage (or lack thereof). Most stiff foods I work with I cut thin enough that it's flexible anyway.
Every so often I have to cut bigger chunks something and it's nice to find it not sticking, but for what I do it's a rare bonus.

I personally rate a thin knife higher, but really it depends on the job at hand.


----------



## aichmophobia

I was about to order this knife until I found this post on Google. Guess Damascus is just for the look, not protecting the blade much. And there's still uncertainty for such a high hrc and 3% carbon. Maybe some of those 20% high chromium binded with 3% high carbon, making the carbon distribution uneven along somewhere.

Maybe that's why Japanese chefs still trust and use their carbon steel knives or very low chromium 0.2 to 05 blue paper steel knives. Stainless were developed for Westerners.

Money saved. Thx.


----------



## JDA_NC

aichmophobia said:


> I was about to order this knife until I found this post on Google. Guess Damascus is just for the look, not protecting the blade much. And there's still uncertainty for such a high hrc and 3% carbon. Maybe some of those 20% high chromium binded with 3% high carbon, making the carbon distribution uneven along somewhere.
> 
> Maybe that's why Japanese chefs still trust and use their carbon steel knives or very low chromium 0.2 to 05 blue paper steel knives. Stainless were developed for Westerners.
> 
> Money saved. Thx.



It's interesting that's what you took away from this thread... He posted videos doing stress tests that 99% of us wouldn't do with our knives - especially higher end, $$$, Japanese knives - and you felt it showed the blades aren't tough?


----------



## aichmophobia

Also, &#26412;&#29138;the original one piece steel is considered more rigid and better, than the sandwiched steels, during heat treatment.


----------



## Pensacola Tiger

"It ain't what you dont know that gets you into trouble. 
It's what you know for sure that just aint so."

Mark Twain (1835 - 1910)


----------



## aichmophobia

JDA_NC said:


> It's interesting that's what you took away from this thread... He posted videos doing stress tests that 99% of us wouldn't do with our knives - especially higher end, $$$, Japanese knives - and you felt it showed the blades aren't tough?



Well, he did those harsh tests because his blade was already chipped, nothing to lose.

If all those tests didn't chip the blade, but one cut on cheese did at the beginning, I would consider that not perfect knife yet.


----------



## aichmophobia

It's like M16, during tests in US soil, all tests past, but in Vietnam, one grit of sand clogged it. Does it make it a good tough gun? I would say it's pretty dangerous.


----------



## LifeByA1000Cuts

"original one piece steel is considered more rigid and better"

Would not attempt to cut something that could bind and break a blade (like hard cheese) with a thinly ground japanese style (hard or even honyaki) blade either


----------



## aboynamedsuita

aichmophobia said:


> Well, he did those harsh tests because his blade was already chipped, nothing to lose.
> 
> If all those tests didn't chip the blade, but one cut on cheese did at the beginning, I would consider that not perfect knife yet.



If you read the thread, early on in the OP indicated that the knife was dropped on a paved parking lot which damaged it before it chipped


----------



## aboynamedsuita

tjangula said:


> If you read the thread, early on in the OP indicated that the knife was dropped on a paved parking lot which damaged it before it chipped





I was partially correct, it's been months since this thread first came out so my memory was a little fuzzy:


Kippington said:


> The initial damage to it actually goes a few months back - I received the knife on my birthday and consequently cracked in the blade on the first day due to playing with my new toy while drunk (I'm sure I am not the only person that does that sort of thing on _*this*_ forum haha!)
> The initial damage to the knife was the part of the chip that goes straight up, the curved part of the chip-out is where the lateral force pulled a good chunk out a few months later.





Kippington said:


> And yeah, I'm pretty certain parmesan cheese would've done no damage to the blade if it was in perfect condition. A previous accidental encounter with concrete is what turned the odds vastly against it holding up to the hard cheese. :O
> Funnily enough, my other ZDP gyuto (same knife but in 240mm) fell out of its "friction fit" saya as I was running across the road and hit the tarmac hard. Luckily and surprisingly, no damage to that one at all.
> I might be wrong, but going off my experience using and sharpening these two knives I think one of them is at the higher end of the bladesmith's target hardness and the other is at the lower end (they're advertised at 66 to 67HRC). Testing will be done on the harder one of the two, assuming I'm correct.


----------



## Kippington

It was completely my fault that it happened. I dropped it edge down on the corner of a concrete step sending a 2mm crack straight up. It was not my proudest moment :O. The rest came out in the cheese later.
As many people have pointed out, I took the opportunity before fixing the edge to show how much tougher these knives are then some people believe. I mean think about it, it was already chipped _and_ cracked, and yet it went though more hard stuff without any further damage.
By the way, the cladding wont save the edge where - low and behold - there is no cladding! 

Here's the current family photo:







The 270mm (top) hasn't changed much in the last year. Probably the biggest change has been to the appearance of the cladding, which has developed a patina in the pattern weld. Now with the pattern standing out, it's looking more like it did when I bought it. This came about slowly through normal use in the kitchen.






It's still reflective, but as I use it quite often at work (which involves people washing it with green scrubbies among other things) the surface has shown some signs of wear. This doesnt bother me at all, as you can probably guess by the appearance of the 240mm!

Many months ago I decided to forgo the appearance of the 240mm and chase performance instead. Using what I had learned in this thread with the 270mm, I went to work with the belt grinder on the 240mm - my everyday user. No more pretty reflective surfaces, I wasn't going to spend hours polishing a knife that was getting scratched up on a coarse belt every few weeks. All I wanted was light weight (its 155 grams), tiny secondary bevels and narrow tapers.






At around this time, Sukenari came out with the "Hairline" version of the ZDP-189 gyuto which, for those of you that don't know, is the budget version of the ZDP gyuto where they go without the pretty patterns and reflective mirror polish to reduce the pri... hey wait a minute! :eyebrow:
It's a lot of fun messing with high quality steel like this and dialing in a work tool to my own personal preferences, all while expanding my knowledge.

The hunger to know more _really_ kicked in after a while so a few months ago I bought some blacksmithing tools and started forging, heat treating and grinding my own knives. I've spent the last few days experimenting with different clay coatings to create nicer looking hamon, but I guess that's a story for another thread. All up, its been a huge amount of fun!


----------



## btbyrd

I know I'm reviving a very old discussion, but this thread was quite the journey. A+ work all around.


----------



## gic

I always use a yo-deba (like the Tojiro DP one) for Parmesan cheese!


----------



## slickmamba

Kippington said:


> It was completely my fault that it happened. I dropped it edge down on the corner of a concrete step sending a 2mm crack straight up. It was not my proudest moment :O. The rest came out in the cheese later.
> As many people have pointed out, I took the opportunity before fixing the edge to show how much tougher these knives are then some people believe. I mean think about it, it was already chipped _and_ cracked, and yet it went though more hard stuff without any further damage.
> By the way, the cladding wont save the edge where - low and behold - there is no cladding!
> 
> Here's the current family photo:
> 
> 
> 
> 
> 
> 
> The 270mm (top) hasn't changed much in the last year. Probably the biggest change has been to the appearance of the cladding, which has developed a patina in the pattern weld. Now with the pattern standing out, it's looking more like it did when I bought it. This came about slowly through normal use in the kitchen.
> 
> 
> 
> 
> 
> 
> It's still reflective, but as I use it quite often at work (which involves people washing it with green scrubbies among other things) the surface has shown some signs of wear. This doesnt bother me at all, as you can probably guess by the appearance of the 240mm!
> 
> Many months ago I decided to forgo the appearance of the 240mm and chase performance instead. Using what I had learned in this thread with the 270mm, I went to work with the belt grinder on the 240mm - my everyday user. No more pretty reflective surfaces, I wasn't going to spend hours polishing a knife that was getting scratched up on a coarse belt every few weeks. All I wanted was light weight (its 155 grams), tiny secondary bevels and narrow tapers.
> 
> 
> 
> 
> 
> 
> At around this time, Sukenari came out with the "Hairline" version of the ZDP-189 gyuto which, for those of you that don't know, is the budget version of the ZDP gyuto where they go without the pretty patterns and reflective mirror polish to reduce the pri... hey wait a minute! :eyebrow:
> It's a lot of fun messing with high quality steel like this and dialing in a work tool to my own personal preferences, all while expanding my knowledge.
> 
> The hunger to know more _really_ kicked in after a while so a few months ago I bought some blacksmithing tools and started forging, heat treating and grinding my own knives. I've spent the last few days experimenting with different clay coatings to create nicer looking hamon, but I guess that's a story for another thread. All up, its been a huge amount of fun!



So this is where it all started


----------



## TEWNCfarms

Kippington said:


> I think some of you guys might find this interesting.
> So at work yesterday I was cutting a big wedge of Parmesan cheese in half when I hear a *_tink_* sound, aaaannnnddddd...
> 
> 
> 
> 
> 
> _(mildly interesting note: you can see micro and macro chipping in this image)_
> 
> Ohhhh man
> The initial damage to it actually goes a few months back - I received the knife on my birthday and consequently cracked in the blade on the first day due to playing with my new toy while drunk (I'm sure I am not the only person that does that sort of thing on _*this*_ forum haha!)
> The initial damage to the knife was the part of the chip that goes straight up, the curved part of the chip-out is where the lateral force pulled a good chunk out a few months later.
> 
> 
> 
> 
> 
> 
> The knife is a Sukenari ZDP-189 Wa Gyuto 270mm at 66-67 HRC. The high hardness of this steel is gonna piss me off now that I gotta take a rather large bit of metal off the knife to remove the chip. I'll try to document my repair progress and post it here if anyone is interested.
> Also, before I start repairs, I would happily oblige if anyone has a request for me to test the knife against something they think could potentially damage the edge. I have two of these ZDP-189 knives and they perform very well, so I'd be more then happy to run tests on the edge for you guys so that this thread doesn't give the wrong impression that the steel is too chippy or brittle.
> 
> Let me know!



Damn Im sorry to hear that, I havent read through all this yet but I hope it was too hard for ya to fix it


----------



## Kippington

TEWNCfarms said:


> I hope it was too hard for ya to fix it



W-was that an insult? :rofl2:

Nah this thread was from three years ago. The knife was fixed back then and is still good today.
I'll take this opportunity to point out that I bought these ZDP knives to use in a professional kitchen, and the amount of sharpening I've done to them is beginning to show.
The 240mm is essentially a petty knife now:






Yeah, no doubt these two are what dropped me head first into the knife-making rabbit hole!


----------



## panda

the shiny one look like ks profile


----------



## Kippington

Yea, slowly losing it's belly curve was a great thing for a while, then one day it went past the sweet spot for me and I was like: You're a petty knife now, deal with it.
It taught me heaps about profiling.


----------



## Nemo

How many belts/stones does take to grind a zdp gyuto into a petty?

:awestruck:


----------



## TEWNCfarms

Kippington said:


> W-was that an insult? :rofl2:
> 
> Nah this thread was from three years ago. The knife was fixed back then and is still good today.
> I'll take this opportunity to point out that I bought these ZDP knives to use in a professional kitchen, and the amount of sharpening I've done to them is beginning to show.
> The 240mm is essentially a petty knife now:
> 
> 
> 
> 
> 
> 
> 
> Yeah, no doubt these two are what dropped me head first into the knife-making rabbit hole!



Haha holy **** thats crazy!!!! It for real is a petty knife, yeah a friend bought me a cheap sekizo santoku and Ive already sharpened it so much in just 5 months where its now a gyuto/petty knife, hes the one who pushed me down the rabbit hole! Now I have a sick Masashi Kobo SLD in the Mail today, thanks Danzo! Haha and I meant to say wasNT too hard for ya. Im interested to read through this thread though when I get some time. What are you main kitchen/work knives now?


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## Kippington

TEWNCfarms said:


> What are you main kitchen/work knives now?



The ones I make, of course! :laugh:
I love to create knives with different profiles and grinds, then test their performance in a professional setting - I learn quickly this way. The non-stick ones and the lasers are my favorites, I will continue to mess around in those fields.


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## TEWNCfarms

Kippington said:


> The ones I make, of course! :laugh:
> I love to create knives with different profiles and grinds, then test their performance in a professional setting - I learn quickly this way. The non-stick ones and the lasers are my favorites, I will continue to mess around in those fields.



Haha I hear that! Id love to be able to buy one of yours one day! 

Im really struggling with this Masashi I have, Im trying my hardest to get my sharpening down to unleash food release, it definitely has a convex edge, but I cant get it to release a potato. Ive tried 70/30 and even alternated the 70 from left side to right side. Ive done korins micro bevel technique, JKIs micro bevel technique, but I can Ever get it right! And of course I didnt try it out whenever I got it, I sharpened it first so I fear I may have messed it up! Any suggestions? Videos? Ive read through your asymmetry thread multiple times, and Ive tried to do that but still cant get it...


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## Jville

TEWNCfarms said:


> Haha I hear that! Id love to be able to buy one of yours one day!
> 
> Im really struggling with this Masashi I have, Im trying my hardest to get my sharpening down to unleash food release, it definitely has a convex edge, but I cant get it to release a potato. Ive tried 70/30 and even alternated the 70 from left side to right side. Ive done korins micro bevel technique, JKIs micro bevel technique, but I can Ever get it right! And of course I didnt try it out whenever I got it, I sharpened it first so I fear I may have messed it up! Any suggestions? Videos? Ive read through your asymmetry thread multiple times, and Ive tried to do that but still cant get it...



Food release has more to do with the grind of the knife than the edge you are putting on it. It may be a blade that just doesn't have great good release. You are probably laboring in vain. Also finishes play a part.


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## TEWNCfarms

Jville said:


> Food release has more to do with the grind of the knife than the edge you are putting on it. It may be a blade that just doesn't have great good release. You are probably laboring in vain. Also finishes play a part.



Yeah. Thanks


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## Carl Kotte

Dardeau said:


> I use a mallet and and the boss's knife.



This is so incredibly funny. Not intending to revive an old thread - just want to highlight (and thereby spread!) this quote.


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