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bieniek
04-20-2012, 06:41 AM
http://i107.photobucket.com/albums/m310/carl00s/100_3862.jpg

http://i107.photobucket.com/albums/m310/carl00s/100_3864.jpg

http://i107.photobucket.com/albums/m310/carl00s/100_3868.jpg

http://i107.photobucket.com/albums/m310/carl00s/100_3854.jpg

Maybe some of you is used to seeing that. Im not.

Vladimir
04-20-2012, 08:07 AM
I have the feeling that this Deba used for cutting nails
:aikido:

Marko Tsourkan
04-20-2012, 08:29 AM
Over-hardened, it seems, not uncommon from Japanese makers. You might have to temper it in your oven (without a handle, or course) if the chipping continues. I have done it with some knives with good results.

M

Lefty
04-20-2012, 08:57 AM
Marko, you're likely right, but do you think maybe the user went through the spine and didn't use the heel? And if this isn't the case, might a micro bevel that graduates into the primary work to avoid further issues? Of course, the heel will have to be properly utilized in conjunction with the tweak, but you get what I'm saying.

JKerr
04-20-2012, 09:15 AM
The deba looks like it hasn't hit the stones yet. If it's been used with the OOTB edge, it honestly wouldn't surprise me that it's so chipped. Having said that, I've never used whatever brand that is ( I assume Gesshin Hide in light of the other thread) so I could be wrong.

Can't speak for the yanagi, looks well patina'd so I assume it's been introduced to stones.

Cheers,
Josh

JMac
04-20-2012, 09:33 AM
I think you may be on to something. Doesn't look like it hit the stones. Don't see any type of uraoshi line. that will help strengthen the edge.

schanop
04-20-2012, 10:31 AM
I've had a few debas, and most have chipped a bit until after a few rounds on the stone. +1 on proper uraoshi. My new hide little ko deba comes with about 1mm thick edge on the back side and needed only a few quick passes on aoto. Bevel was also easy to follow, some quick touch up on aoto and it was ready to be a little beast for small fish.

http://2.bp.blogspot.com/-58JL_fs_iso/T4ltRuVOihI/AAAAAAAAAgI/IFaVbRdCyNU/s400/PICT0146.jpghttp://4.bp.blogspot.com/-1lBGYz1h7Uk/T4ltTL3A3GI/AAAAAAAAAgQ/hndh1-IWVAA/s400/PICT0151.jpg

Marko Tsourkan
04-20-2012, 11:33 AM
I was thinning a knife recently, white steel with a stainless core, on Beston 500 stone. I noticed chips forming on the edge during thinning process.

I asked Devin about it and he said that steel was over-hardened and was chipping at grain boundaries, and he suggested one-hour tempering session (one or two) to reduce hardness. I did that and the chipping stopped. I did that in knife-making oven but it can also be done in a kitchen oven. Be advised that the knife will get slightly oxidized and will need to be refinished.


M

Lefty
04-20-2012, 11:37 AM
Cool. If you had to guess, how hard was it, and how far down would you have tempered it?

Marko Tsourkan
04-20-2012, 11:40 AM
I re-tempered the knife I worked on at 365F for one hour. That should have reduced hardness by one point or less.

Chipping usually starts at 63-64RC, so with one or two tempering sessions, hardness can be brought to 61-62RC. It's hard to say for sure, hands-on testing in between will be needed.

M

bieniek
04-20-2012, 12:29 PM
Thanks for all the response.

Now. My best bet is just simply users technique is not existant. But its quite weird spot for chips.

I will sharpen the blade and check next time vs tuna.
If it happens again, then I have a problem.

Altough its new knife, not every buyer is knife sharpener and not every can microbevel own knives. It shouldnt happen OOTB.
Back is honed. The line is perfect and thin, but its there.

I chopped some heavy bones with my yoshihiro and didnt have that problem once.

maxim
04-20-2012, 02:09 PM
I asked Shigefusa ones and he told me he make edges on them very thin, to thin, so user can easier adjust then to him self.
It depends what bones you cutting, big or small.
Deba is special knife and not everybody have them in they kitchen. So i will expect to adjust it to my self when i buy one.
I definitely dont think that it was overhardness, but just not adjusted for your use :D

Dave Martell
04-20-2012, 02:35 PM
From a practical standpoint I'd suggest making the heel (maybe 1" or so) more obtuse than the rest of the edge and use this section for heavy work. Even then though I think it's best to lean on the knife versus whack on the knife when doing bone sectioning. I've seen a lot of deba repair work over the years and once a knife (and it's user) is adjusted this way chipping problems seem (for the most part) to disappear. I'm not an expert in the use of these knives so please understand that when taking my suggestions here, I offer only what I know from working with people who use these knives themselves and have had problems.

On the heel, you can also go one step further and make a bevel on the backside (for real heavy use) on the first 1" or so, see the below diagram...

JBroida
04-20-2012, 03:01 PM
Beiniek, i will also PM you privately about this to explain more about this and how best to handle it but i wanted to make a few public statements as i feel they will be of help to many others around here. Also, @Marko, i hope you do not take what i am about to say as a personal attack... that is not my intention. Please dont mistake my forwardness as trying to be an ass... that is not my intention at all.

Ok... here we go.

One of the first things I tell people when we talk about knives is this-
As a general rule, the more money you are spending on something, the more that will be required of you skill-wise, experience-wise, and technique-wise to be able to use and care for that effectively.

This is absolutely true when it comes to kitchen knives… and especially Japanese kitchen knives. That’s why there are beginner knives, like the yoshihiro, which are softer, easier to use, easier to sharpen, and easier to care for… and higher end knives like the Gesshin Hide, which are harder and require more skill to use effectively. If there wasn’t so much of a difference between the two, I would imagine that very few people in Japan would buy these kinds of knives… and for those who did, I would imagine they would see just as serious chipping issues as you are seeing here. However, that is not the case among professional chefs in Japan (and please understand that these knives are all intended for professional use).

Learning about how to sharpen and care for these knives is very important, and here are a few things that should have been done. First, when using knives like this, you need to do final sharpening (even if the knives come sharp out of the box). This includes uraoshi sharpening, which strengthens the blade. This also may include microbeveling the knife (either at the heel, or along the entire blade, based on your personal preference, technique, and what you plan on doing with the knife). If these techniques are not possible for you, I would recommend sticking to a beginner blade like the yoshihiro and practicing/learning until this makes sense and is possible.

Likewise, skill in using the knife is paramount. Chips like what you are showing here occur out of misuse more than anything else. Make sure you are using the knife correctly before anything else. It looks like you either cut bones in the wrong place, had an unsteady hand while doing so, and/or did so at the wrong angle. That, in combination with a lack of proper sharpening, could easily cause the problems you are seeing here.

Re-tempering a blade should never be on your list of things to do. Not only does it take away what makes the blade what it is, but it also shows a lot of arrogance thinking that the problem lies in the blade rather than your technique. I don’t think anyone here on these forums has the experience to say what an appropriate heat treatment is for knives like this… and I say this for the following reasons (I am including normal end users, vendors, knife makers, etc. in the following statements)-
*very few, if any, users here have serious and significant experience using these knives as intended in a professional environment
*very few, if any, users here have learned proper technique from qualified and experienced users of these knives
*most users experience with these knives is limited to just a couple of years (and when I say this, I mean significant experience where the knife is being used, cared for, and sharpened correctly)
*very few, if any users here have spent significant time with Japanese blade smiths learning about the construction, making, heat treatment, etc. involved in making these blades
*very few, if any users here have spent significant time with Japanese professional sharpeners learning about how these blades are sharpened and cared for

Most of us (myself included) began learning by just trying things out ourselves. We had some limited videos, books, and a ton or hearsay to go on, but that was about it. Its been more of a trial and error process than anything else and there has been a significant lack of understanding of why thing are they way they are, how things are intended to be used, and the subtle nuances therein. Until recently, I was in the same boat… I now have the opportunity to spend time with sharpeners, blacksmiths, and chefs in Japan and constantly use them as a resource when I have questions about why and/or how things are done.

To Bieneik, please feel free to use me as a resource as you go about fixing your knife and learning how to use it properly… that is exactly what I am here for. I’ll shoot you a PM in a bit.

Eamon Burke
04-20-2012, 04:22 PM
Great post, Jon.

mpukas
04-20-2012, 04:51 PM
well said, Jon.

mhlee
04-20-2012, 05:02 PM
Given that Dave's diagram is in Japanese, I am assuming that this is something that is done, but in my experience, putting a microbevel on the back side edge of the blade doesn't seem to lend itself well to uraoshi sharpening. In order to then be able to take off the burr, you would have to lift up the knife (spine side up) and push, which would further establish the microbevel. This experience is based on what I did to my Kanehisa yanagiba based on what I read back in the day - pre-internet - and I still haven't been able to remedy that.

I still can't deburr the knife without changing the angle. I only do a little uraoshi sharpening on the back side, then deburr on felt or paper because i can't hit the burr without raising the spine.

Sarge
04-20-2012, 05:05 PM
Great information as always Jon, my favourite thing in his post,while it came as no surprise was how you continue to pursue information and knowledge from the craftsmen, sharpeners and chefs. I would also say you didn't come across as an ass at all.

Marko Tsourkan
04-20-2012, 05:13 PM
I don't think what I posted was arrogant, but let me explain and hopefully demystify some things.

There is an easy test to check whether an edge is chipping or rolling (too hard or too soft). It involves rolling a thinly sharpened edge with a moderate pressure on a brass rod. If it chips, a maker has to temper more, if it rolls, the edge is over-tempered. Some makers here in the US spend a great effort coming up with a 'sweet spot' for astenitizing and tempering temperatures, where the resulting edge is nether rolling nor chipping at 62-63RC hardness.

The knife I re-tempered was clearly over-hardened, (you don't often see chunks of edge falling out during thinning on Beston 500) and the chipping stopped after 1 hr tempering session.

Thickness of the edge matters when it comes to edge deformation, but generally, a hard edge will chip while a soft will roll. From the picture it looks more like chipping rather than rolling (but I am not 100% sure without seeing it upclose), so that makes me think that the edge is overly hard. I have owned a deba and garasuki and seen some chipping (sustained after cutting through bones), but nothing like that.

The "proper" sharpening technique would involve putting a bevel, to increase a cross-seciton of the edge as everybody else has mentioned.

M

tk59
04-20-2012, 05:24 PM
Tests are funny things. They are arbitrary and have different significance to different people. You may be right, for all I know but personally, I'd hesitate to criticize the product of someone who by any measure is a master at his craft. I'd also hesitate to imply that every blade, regardless of steel, intended use and blade design should be hardened to 61-62 hrc.

Dave Martell
04-20-2012, 05:34 PM
On the heel, you can also go one step further and make a bevel on the backside (for real heavy use) on the first 1" or so, see the below diagram...



Given that Dave's diagram is in Japanese, I am assuming that this is something that is done, but in my experience, putting a microbevel on the back side edge of the blade doesn't seem to lend itself well to uraoshi sharpening. In order to then be able to take off the burr, you would have to lift up the knife (spine side up) and push, which would further establish the microbevel. This experience is based on what I did to my Kanehisa yanagiba based on what I read back in the day - pre-internet - and I still haven't been able to remedy that.

I still can't deburr the knife without changing the angle. I only do a little uraoshi sharpening on the back side, then deburr on felt or paper because i can't hit the burr without raising the spine.



Thanks for making me think more on my statements I made Michael, you made me realize that I should add a warning to what I said above regarding adding a backside bevel on the heel. I don't want everyone running out and doing this to their knives.

I want to make it clear that this is for a deba ONLY and it is IMO a last resort.

I feel that the user needs to look at their technique and possibly add a front side micro-bevel (heel or full length) to the knife before ever thinking about using the back side heel bevel thing I showed in the above diagram.

schanop
04-20-2012, 05:36 PM
Great post Jon.

@mhlee, you can try the method Jon described in this video for making deba micro bevel: high angle micro bevel for one third along the front side, and the back side. This wouldn't get in a way of uraoshi, very handy method. There are some handy tips about using debas too.


http://youtu.be/ueQVDlvfL_c

Marko Tsourkan
04-20-2012, 05:46 PM
Tests are funny things. They are arbitrary and have different significance to different people. You may be right, for all I know but personally, I'd hesitate to criticize the product of someone who by any measure is a master at his craft. I'd also hesitate to imply that every blade, regardless of steel, intended use and blade design should be hardened to 61-62 hrc.

There was no criticism coming from me toward anybody, just a general observation - hardness and sharpness have been characteristics of Japanese knives for as long as I know it.

I do post on subjects that I have studied and have first-hand experience with and have discussed these topics with people who have a lot of experience in area of metallurgy and heat-treatment, so some of the information is derived this way.

Yes, there might not be such a thing as 'optimum hardness' for everybody, but it is a fact that it's much harder to break (destruction test) 61-62RC hardened steel than 63RC (and higher) all other things being equal (similar grain size).

M

JBroida
04-20-2012, 06:12 PM
Marko-
Not all knives require the same degree or hardness so that kind of testing is not necessarily applicable. The kind of heat treatment required for each particular type of knife, and even within that, the difference between beginner knives and advanced knives, will differ greatly with some being much more brittle than others.

I do happen to believe that its arrogant to think ones knowledge of the knives, steel, and how they are used trumps years of experience and real life testing and use. Whether its you or Devin or someone else, I cant think of anyone here that has the experience to make comments like this. This doesn’t mean that I think you (or devin for that matter) have a poor understanding of heat treatments. I just think that the scope of that understanding and experience doesn’t include the types of knives you are talking about here. Likewise, I think when making judgments on knives, its important to consider the knife as a whole (including the design features, intended use, intended user, etc) as that maker thought of, as opposed to imposing your own understanding/opinions of the design features, intended use, intended user, etc. onto that knife/system of thinking.

In general its a very limited view you have on this and until you really and truly understand the knife, how to use it, and why it is the way it is (and the design and heat treatment ARE intentionally that way), it will be very difficult for you (or anyone else) to make judgement like this.

Marko Tsourkan
04-20-2012, 06:19 PM
I guess, my answer to this will to make knives that will hold longer edge, won't chip or roll, will have an excellent grind, fit and finish, will come with top notch handle and sayas work - all this without years and years of experience. Enough said. :(

M

JBroida
04-20-2012, 06:23 PM
please and by all means... i always enjoy seeing your work... i guess my point is you dont know what you dont know (not just you, but as a general statement) and if it were me in your shoes i would think twice before making adjustments to others work without understanding why things are the way they are first.

If this was a problem i was having, my first question would be to myself of what i am doing wrong and how i can improve... not immediately assuming the problem is with the knife.

Eamon Burke
04-20-2012, 06:27 PM
Jon, is there any insight you can offer regarding what the positive qualities are that this less rugged heat treatment offers?

Dave Martell
04-20-2012, 06:49 PM
I like how we can have an in depth discussion like this and not blow our stacks. We all have lots that we can learn from each other.

TB_London
04-20-2012, 06:52 PM
I remember reading somewhere that some knives are prone to chippiness initially but after the first few sharpenings they settle down. Remember reading something on the old forum about instructions being sent out from kikuichi(?) that mentioned this.
Given the lack of accuracy of home ovens vs PID HT ovens anyone considering tempering should use a separate thermometer IMO, but this would be last resort

Crothcipt
04-20-2012, 07:19 PM
I know my 2 Tanaka's have higher hrc ratings (63-65). I pretty much took the otb edge off with a honing rod, on my sankto knife. I had a hard time putting a new edge on it until I went and reread the hrc levels (I since have bought some stones that this isn't a problem). I would never even think about taking the hrc lvl down, but I am not a knife maker either. After reading this I want to now.(trash knife that is). Man I learn so much stuff here.

JBroida
04-20-2012, 07:27 PM
Jon, is there any insight you can offer regarding what the positive qualities are that this less rugged heat treatment offers?

in this particular case, its what chefs are looking for in Japan... they want better edge retention with the understanding that the cost will be a more brittle knife. However, because this is never their first knife, they have had years to work on technique so as not to have problems with chipping. What is interesting is this... i've tried a lot of blue #1 knives and these are the least chippy i have tried. Also, its worth noting that the HT in the debas will be slightly softer than the usuba and yanagiba in the same line.

As a side note, sara is saying this in the background as i type:
"The chefs using this in japan dont feel like its chippy, so chippy is really more of a skill thing than a knife thin. They know their steel well and talk to chefs all the time to make sure the heat treatment is producing the results they and the chefs are looking for"

Its true that these particular guys are always talking to chefs using their knives and making sure things are working the way the expect.

Eamon Burke
04-20-2012, 09:17 PM
I can relate to that. Especially for sushi, it's way more important to have a knife that just cuts great than anything else--it's worth babying it when the stakes are that high. Plus, from watching the JKS videos, you can tell the technique they are employing is very precise and demanding. That said, I like that we are focusing here in the US on making knives versatile and friendly without going the German route and selling axes.

I would like to see how those chefs would like a blade in s30v...wild edge taking/holding, requires care, and totally stainless to boot.

I wonder why it is that a propensity for edge chipping does not result in more carbide popout. But then again I am not a metallurgist.

I feel like when Alton Brown asks a question and Debbie Duchon pops up because someone said "Nutritional Anthropologist". Where's Larrin when you need him?

tk59
04-20-2012, 10:00 PM
...I like that we are focusing here in the US on making knives versatile and friendly...

I would like to see how those chefs would like a blade in s30v...wild edge taking/holding, requires care, and totally stainless to boot.

I wonder why it is that a propensity for edge chipping does not result in more carbide popout. But then again I am not a metallurgist.

I don't feel like my Carters, Heijis, Yoshikanes, etc. are not versatile. All of these blades, as well as many others (even VG10) are "chippy." Not friendly? Tell it to all the people with Tojiros and Shuns, lol.

Some might like it but the bottom line is they use what they use because carbon steel gets bloody sharp. What I'm wondering is whether or not they'd go for AEB-L hardened to 63 hrc, for example.

Edge chipping in this case, has to do with the hardening of the matrix. Carbide pull out has more to do with the size of the carbides or clusters thereof and the amount of matrix around them to hold them in place.

That said, I've been wondering how Larrin is doing, as well.

Eamon Burke
04-20-2012, 10:26 PM
Well, the high dollar, high performance knife steels in the US are focused on the mindset Mr. Tsourkan was suggesting, not excelling at one specific task, like holding a razor edge to the detriment of it's ability ti withstand boneheaded abuse. We want to hack 2x4s and shave with the same knife.

JBroida
04-20-2012, 10:32 PM
Well, the high dollar, high performance knife steels in the US are focused on the mindset Mr. Tsourkan was suggesting, not excelling at one specific task, like holding a razor edge to the detriment of it's ability ti withstand boneheaded abuse. We want to hack 2x4s and shave with the same knife.

and theres nothing wrong with that... its just not what this knife is about

Eamon Burke
04-20-2012, 10:35 PM
Yup. I always thought the two schools can coexist and learn from each other. :thumbsup:

Lefty
04-21-2012, 12:12 AM
Now this is an interesting thread! I keep coming back to it, hoping for an update.

eshua
04-21-2012, 02:18 AM
I've worked sushi for 5 years, before that 10 years at fish markets and restaurants.

My boss has owned sushi bars for 7 years.

One of our older guys just retired after 20 years making pieces.

Some of the advice I've scrounged up here has totally changed our excitement about knives and work in general.

We all have knives that perform satisfactorily, and agree its 90% finding a tool that can handle the job when you have to power though a shift, but then there is this whole mess of science, tradition, metallurgy, and excellence, and that I don't know jack about, but its really fun to listen to people who are a lot closer to that mess than me. Keep it up!

And now on to the what are you drinking tonight thread LoL.

Peco
04-21-2012, 06:22 AM
Rock on Jon. Respect!

mano
04-21-2012, 11:13 AM
Jon's posts on this thread are among the most relevant of any on the internet for people who use Japanese knives. But he's just scratching the surface of what they're all about structurally, culturally, the metallurgy and intended use. Keep posting, Jon!

FWIW, when he uses the word arrogance, don't confuse it for hubris. He's talking about anyone -innocently and with the best intentions- who thinks they know more/better about a particular knife than the master who made it.

DK chef
04-21-2012, 11:26 AM
i think Jon always post with the best intentions, always good posts and he is always so modest.

keep it up :D :D

TB_London
04-21-2012, 03:23 PM
i think Jon always post with the best intentions, always good posts and he is always so modest.

keep it up :D :D

+1 though so does nearly everyone else here, it's what is great. This forum isn't a storefront it's a place for discussion and thought

David Metzger
04-21-2012, 06:07 PM
As far as I know these are hand made knives with a hand done in forge heat treat with cooling and tempering by master craftsman. The hardness is not typically tested. Correct me if I am wrong. The point that these hard HRC knives are made this way on purpose is most likely valid. It is also valid that probably most people in US would do better with a less hard knife. I for one really appreciated Marko Tsourkan's comments. I believe he has certainly an expert level of knowledge in this area. After reading Jon's comments I would certainly try to use good technique and maintenance before I resort to a tempering change.

There are a lot of possibilities here and assumptions. And most comes down to just opinions.

David

JBroida
04-21-2012, 07:03 PM
there are less hard knives out there for people to buy though, and in the cases where that is right for them, why not buy one of those knives?

tk59
04-21-2012, 07:25 PM
there are less hard knives out there for people to buy...It seems to me that maybe 99.99% of all knives made in Japan are less than 62 hrc. So actually, it is hard to find the really hard knives unless you know about a handful of shops here and there. The internet has changed a lot of things in the last few years.

Schtoo
04-22-2012, 12:53 AM
there are less hard knives out there for people to buy though, and in the cases where that is right for them, why not buy one of those knives?

Because the less hard (cheaper?) knives aren't as pretty? Perhaps folks want 'the best' warts and all, and if that means getting something that could be beyond their needs/capabilities, then that's ok, so long as it's "the best".


You know why Jon, just as well as I do. ;)

Stu.

JBroida
04-22-2012, 01:04 AM
Because the less hard (cheaper?) knives aren't as pretty? Perhaps folks want 'the best' warts and all, and if that means getting something that could be beyond their needs/capabilities, then that's ok, so long as it's "the best".


You know why Jon, just as well as I do. ;)

Stu.

lol

bieniek
04-22-2012, 10:52 AM
Thank to all of you for all the incredible comments. Im hoping many will use the knowledge.

As to the Jons post what I have to say is I am very very sceptical if all of people buying those kinds of knives are pro chefs with right technique. I dont exactly know the percent of those, but how many of them is here?
That is why Im totally not surprised someone like my boss bought one.

I think the chips were 100 [one hundred] percent owners fault.
BUT today I started a little bit on resharpening and found out that in exactly this spot where chipping happened, there is overgrind close to edge, I didnt noticed before, but now when I started working on DMT to get the secbevel flat, its obvious. Also the actual edge bevel was smaller in that spot. I hope to get a picture of it but the weather is bad and dont know if I manage.

Would one sharpening before prevent chipping is pure speculation.
Would proper use by skilled user prevent it? I am 100 percent sure.

And there is another thing bothering me, I cannot help it and not write that.

When I was still enthusiast of japanese chefs and knives I was going around asking sushi chefs if they needed sharpening, free of charge. Even though some of them had knives in very bad condition, they wouldnt go for it.
What about the care for the fish and cell structure?

And maybe its cause my style or quality of sharpening is not what they are used to, but before statement like this check my kasumi thread, I dont know where I could improve on babying my single bevels [apart from better polishing]
I didnt have a child then, and a lot of time, so I was polishing knives for others also, free of charge, just for the joy of it...
Those who eventually took the risk and gave me knives never had problems with chipping, especially on debas.

So what I mean, is I hear all the time about chefs so passionate about cutlery and babying their knives, and something else Im seeing.

Something like this
http://www.youtube.com/watch?v=Rwy5hT0nCCQ

or this

http://www.youtube.com/watch?v=qZj0I...layer_embedded

***?

bieniek
04-22-2012, 12:29 PM
couldnt get any better

http://i107.photobucket.com/albums/m310/carl00s/100_3894.jpg

tk59
04-22-2012, 01:19 PM
Wow. Definitely an overgrind. Do you have calipers? How much thinner is the edge there?

schanop
04-22-2012, 04:20 PM
What's the second link Mike? I think it is broken. The first video is loooong . fetching for watch later now :-)

wrt to the picture, how many passes on dmt was it? If it was only a few passes I don't feel (just me) that those low spots and over grind on and edge is any serious issue. Although Jon said that these hide knives usually come with a solid edge, but it is also quite traditional for users to do honhatsuke themselves first.

Citizen Snips
04-23-2012, 02:47 AM
here is my take on this very intriguing thread.

knives are knives and they do not need to be judged in the typical way. some knife makers are better than others and because of that, some knives cost more due to supply and demand, materials, maker quality etc, but that is not what we are talking about here. a knife will never chip like that if it wasn't used. let a knife sit in the box and it will look great as long as you have it, but that is not what the knife wants to do. we all enjoy our knives here because we have an intent on using them (a few drawer queens aside) and when we do, we learn about them in an intimate way that we can only describe using words. this does not do justice to the actions we are doing.

the point im trying to make is there is a wealth of knowledge here that should be taken very seriously as all of us have different experience levels with professional kitchens, knife making, and knife sharpening which all together make up our passion here. i would make the suggestion that you learn by doing and the knife is along for the ride. there are a lot of things you could try but i think using your head and getting the most out of all your experience is the only way to judge your progression at any of these skills.

there isn't anyone on this forum that knows everything and cannot learn from the other members here. we all know this and strive to add threads about experiences here and thats all i believe has happened in this thread. looking down on others is not what we do here and i am so glad it hasn't come to that.

bieniek
04-23-2012, 01:09 PM
TK I didnt measure. There wouldnt be much of a difference, but it was there.

Photo was taken after up to 200 strokes. Blue diamond. I just go by the feel and looks of it. Dont count strokes.

The first video is long, but in the first half you can see things there... :)

The other one were itasan18s knives in his video on sharpening... Did you see that "deba"? It looks like a MAC knife with that funny rounded tip.

As I said, my boss dont hae a clue about sharpening, and that is the issue here.

You can see on the photos : good blade+poor skill=disaster :D

Photos to come, I just have the polishing job to be done now.

What can I say about the repairing so far, this is the nicest steel I have worked with. It was just such an easy fix, I have problems believing it. And it was a damage.

schanop
04-23-2012, 05:12 PM
Thank bieniek. I've seen itasan's video before, just the link that you put in that was broken :spiteful:

Agreed that the steel in hide knives is not difficult to sharpen but can't comment yet on fixing chip (haven't chipped mine yet).

memorael
04-23-2012, 08:47 PM
I don't know if people are going to like this but o well, most knives (even Doi's and whatnot) that I have owned ALL come with some sort of imperfection. Damn even DT midtechs had some overgrinds here and there. The point is, unless your dropping a wad of cash for a full custom most likely the knife WILL have a problem here and there. Just live with it, fix it, use it, have a great time with it, its a knife not a foken Van Gogh to look at.

Dave Martell
04-23-2012, 11:59 PM
You want mamma mia? I'll give ya mamma mia! :lol2:

http://www.kitchenknifeforums.com/attachment.php?attachmentid=6381&d=1335239882

http://www.kitchenknifeforums.com/attachment.php?attachmentid=6380&d=1335239874

Shinob1
04-24-2012, 12:05 AM
Looks like a nice toothy edge. :justkidding:

You want mamma mia? I'll give ya mamma mia! :lol2:

http://www.kitchenknifeforums.com/attachment.php?attachmentid=6381&d=1335239882

http://www.kitchenknifeforums.com/attachment.php?attachmentid=6380&d=1335239874

SameGuy
04-24-2012, 12:14 AM
That is a sad Tsukiji. Sad.

Crothcipt
04-24-2012, 12:26 AM
I'm am very glad I am not fixing that one. (not like I could):scared2:

memorael
04-24-2012, 02:05 AM
You want mamma mia? I'll give ya mamma mia! :lol2:

http://www.kitchenknifeforums.com/attachment.php?attachmentid=6381&d=1335239882

http://www.kitchenknifeforums.com/attachment.php?attachmentid=6380&d=1335239874

HAVE FUN! :razz:

bieniek
04-24-2012, 07:43 AM
Mamma Mia Dave!!

Project got finished. This is such a lovely knife to work on, such a pleasure to polish it.

What you think ?

http://i107.photobucket.com/albums/m310/carl00s/100_3909.jpg
http://i107.photobucket.com/albums/m310/carl00s/100_3904.jpg
http://i107.photobucket.com/albums/m310/carl00s/100_3907.jpg

wipe, check, and again
http://i107.photobucket.com/albums/m310/carl00s/100_3908.jpg

http://i107.photobucket.com/albums/m310/carl00s/100_3910.jpg

http://i107.photobucket.com/albums/m310/carl00s/100_3915.jpg

Oh man that lamination line is just beautiful
http://i107.photobucket.com/albums/m310/carl00s/100_3912.jpg
http://i107.photobucket.com/albums/m310/carl00s/100_3911.jpg

http://i107.photobucket.com/albums/m310/carl00s/100_3920.jpg
http://i107.photobucket.com/albums/m310/carl00s/100_3921.jpg

JMac
04-24-2012, 07:54 AM
Looks Great! what kind of stones did you use?

maxim
04-24-2012, 08:12 AM
That is very cool Job !!! Jnats make wonders in the right hands !

TB_London
04-24-2012, 08:57 AM
Nice job, have you added a microbevel?

schanop
04-24-2012, 09:42 AM
Very nice. And you know what! I actually like hide knife with normal surface finishing (those fine hairline 45* lines) than mirror polish one.

Dave Martell
04-24-2012, 10:22 AM
Nice work!

heirkb
04-24-2012, 10:56 AM
Nice job, have you added a microbevel?

Doesn't look like he'll need to given the serious hamaguri that seems to be on that knife. Then again, what do I know? lol

JBroida
04-24-2012, 11:26 AM
this picture made me laugh
http://i107.photobucket.com/albums/m310/carl00s/100_3911.jpg

thats one solution i guess

well done

Andrew H
04-24-2012, 11:28 AM
this picture made me laugh
http://i107.photobucket.com/albums/m310/carl00s/100_3911.jpg

thats one solution i guess

well done

No kidding. I love how the lines just drop off at such an angle that they disappear for a mm. Mind telling us how you went about achieving it?

Halicon
04-24-2012, 11:46 AM
JBroida covered pretty much all but as it's a huge thread and I'm a bit rushed; It looks without a doubt to be a user mistake, those kind of chips are quite commonly seen when a beginner try to work through fish and don't know how to avoid the bones and only cut the weak spots in the fish with any cleaving/push-cutting action.

Attempting to temper a blade... Any blade, even HRC 60 and unless there has been years of study and experience in your background with cold-forged cutlery - forget about it, the refined spherodized molecular structure in the knife will change and god knows what will happen as a result. Send it back to the maker and explain the situation or possibly to someone specializing in the area.

This is the nature of mid to high-quality and cold-forged blades that has been hammered and water quenched. Without the needed skill comes potential catastrophic failure and the nature of use with a Deba only adds to make it worse.

Even Shigefusa style Deba's chip with ease without proper knowledge of how to cut the fish and handle the knife. Regardless of how expensive the knife is the steel can't make up for negative force against something like bones in large fish. This isn't about arrogance or acting superior, these are skills one must have in order to use these kind of blades correctly. If we show the knife the respect it deserves by educating ourselves then they will bless you with a lifetime of screaming sharp use.

Happy cutting everyone

Eamon Burke
04-24-2012, 11:55 AM
Nice job, have you added a microbevel?

More like a macrobevel.

It sure is pretty now though! Any chance for pictures of the backside?

Halicon
04-24-2012, 11:59 AM
BurkeCutlery, it doesn't seem like he want's to show it. Could be a good opportunity to learn a little about Uraoshi and how to work towards Ito-ura.

TB_London
04-24-2012, 12:10 PM
More like a macrobevel.

It sure is pretty now though! Any chance for pictures of the backside?

Lol was looking on my phone screen and couldn't make out the pics enough to know if it was just a trick of the light

Eamon Burke
04-24-2012, 12:17 PM
BurkeCutlery, it doesn't seem like he want's to show it. Could be a good opportunity to learn a little about Uraoshi and how to work towards Ito-ura.

Yeah, that's something I've always wondered about. If you have a chip or a user-induced overgrind that's deeper than the width of the zero bevel on the backside, I don't know how you fix it without over-flattening the backside.

kazeryu
04-24-2012, 12:24 PM
I remember reading somewhere that some knives are prone to chippiness initially but after the first few sharpenings they settle down. Remember reading something on the old forum about instructions being sent out from kikuichi(?) that mentioned this.

I've heard of (and seen) the opposite happen - the initial edge is soft and rolly, but after a few sharpenings it's fine. This is generally due to overzealous use of power buffers causing the outer "shell" of steel to temper.

I was going to say that I don't see how you could end up with a chippy edge that sharpens away, but it occurred to me that "over quenching" might be the culprit -- with the outer shell of the steel acting as a cushion for the interior, sort of like clay does when creating a hamon.

Knifemakers, does that make any sense?

Halicon
04-24-2012, 12:30 PM
It's a bit like balancing a scale. In order to reach Ito-ura, the hollow has to be very thin in the first place - so establishing one after a large chip is my usual procedure. One needs to focus the pressure with your fingers -only- on the steel laminated to the iron (only the ball of your fingers on the steel, not on Jigane at all! It will remove the Ito-ura and restore the balance to the "scale") and keep the knife stable on the stone while putting decent pressure on the end that makes the edge and about 1/3 to 1/4 of the same pressure on the area where the hollow reaches the spine.

Naturally you have to grind the chip away but if you do the Uraoshi in the manner I described above then the surface towards the edge will become smaller and kiwer and the contacting area on the stone smaller as well (leading to Ito-ura with enough time spent) as the "supporting" flat near the spine remains practically the same size so you're constantly forcing the contacting area near the edge of the hollow to become smaller and eventually it reaches thread-back - Ito-ura.

Very rough description though but I hope it helps you give an idea. The hollow at the spine is basically the life of the craft, as long as you don't grind there you will always be able to repair practically anything and also restore the Ito-ura. Making an Ito-ura the first time can be very hard and time-consuming however as one has to carefully observe how much pressure you put and what results it gives and then correct it.

In essence, what we are trying to perform with an Ito-ura is a hollow that is completely flat yet sloping a little in nature to have a tiny contact area where it leads to the edge.

Quite rushed right now and I'm sure much of it isn't making sense. Made a quick edit but will return later tonight.

bieniek
04-24-2012, 12:49 PM
http://i107.photobucket.com/albums/m310/carl00s/100_3927.jpg

This is the back side. I just forgot to add it.
Why wouldnt I like anyone to see it? Im just going outside to try to get better shot :)

Eamon Burke
04-24-2012, 12:52 PM
Nice. Sure is pretty!

Halicon
04-24-2012, 01:00 PM
Bieniek, well it's quite obvious to me that you didn't perform an Uraoshi and need some good flat coarse synthetics. Those kinds of jobs are common for a polisher and performing the Uraoshi is actually seen as much more important than the front bevel and always the first thing we repair in traditional JP knives. While it will cut and cut well, it won't be the same performance as if it was truly flat both on the Ura and the front bevel as I saw that you concaved the Jigane with your finger stones. So there's no accurately flat surfaces on either side of your knife, limiting it's performance as the edge can't reach the same small size of the sharpening stone particles due to it not being completely touching the stone.

I wish to express however that this isn't criticism, you have done a great job with your knife and you spent many hours on it to make it look good again. I'm explaining the proper traditional procedure of how a polisher repairs knives like these. Please do not be offended, this is what I do during my day and I'm only trying to share the proper information as I know extremely few chefs that knows how to establish an ito-ura.

It looks like a fine Degyuba though. :D

bieniek
04-24-2012, 01:04 PM
I used DMT blue for the starters. Then JNS 1k. Then my small setup of three jnats.
Then all different kinds of fingerstones and pressures, then two polishing compunds on hard felt. Just to bring out the depth.

Thanks Maxim, I really dont think my hands are right, not quite yet :) But Im trying hard

TB, yes, there is a huge-arse microbevel.
But as Herikb mentioned, there is starting of two-angled edge. The lower lower part of it isnt ground at all at much higher angle. It just looks huge because of the amount of metal that I had to remove.
Now, why would I do that and dont take more metal from above the bevel? Strength, which I believe this knife will need.

Schanop, If you have a king its possible to make it darker and not mirrored. But I dont have it anymore, and the effect from binsui or JNS 1K alone isnt too good lookin.

Jon, Andrew, I will try to get better photo of it. There is not much angle difference. The line looks crisp because I have steady hand during my strokes. And I didnt blended two bevels together, as I easily could, just cause I want the owner of the knife to see it. And remember what he did. This was just a stupid stupid waste of metal. Good metal

Andrew H
04-24-2012, 01:08 PM
I used DMT blue for the starters. Then JNS 1k. Then my small setup of three jnats.
Then all different kinds of fingerstones and pressures, then two polishing compunds on hard felt. Just to bring out the depth.

Thanks Maxim, I really dont think my hands are right, not quite yet :) But Im trying hard

TB, yes, there is a huge-arse microbevel.
But as Herikb mentioned, there is starting of two-angled edge. The lower lower part of it isnt ground at all at much higher angle. It just looks huge because of the amount of metal that I had to remove.
Now, why would I do that and dont take more metal from above the bevel? Strength, which I believe this knife will need.

Schanop, If you have a king its possible to make it darker and not mirrored. But I dont have it anymore, and the effect from binsui or JNS 1K alone isnt too good lookin.

Jon, Andrew, I will try to get better photo of it. There is not much angle difference. The line looks crisp because I have steady hand during my strokes. And I didnt blended two bevels together, as I easily could, just cause I want the owner of the knife to see it. And remember what he did. This was just a stupid stupid waste of metal. Good metal

Thanks for the explanation, Bieniek. Great job.

bieniek
04-24-2012, 01:08 PM
Bieniek, well it's quite obvious to me that you didn't perform an Uraoshi and need some good flat coarse synthetics. Those kinds of jobs are common for a polisher and performing the Uraoshi is actually seen as much more important than the front bevel and always the first thing we repair in traditional JP knives. While it will cut and cut well, it won't be the same performance as if it was truly flat both on the Ura and the front bevel as I saw that you concaved the Jigane with your finger stones. So there's no accurately flat surfaces on either side of your knife, limiting it's performance as the edge can't reach the same small size of the sharpening stone particles due to it not being completely touching the stone.


Not offended at all.
Could you please elaborate?
Especially the bit on concaving jigane? Im just having a problem imagining what you mean, thats all, but Im very curious

Halicon
04-24-2012, 01:14 PM
At the heel where the geometry of the bevel falls down the Jigane seems to fall into a tiny concave. It looks like you didn't compensate enough to polish the laminated steel and iron equally as the iron is much softer. Perhaps you used Jizuya for the Jigane as well? It can also simply be the picture, judging these things by eye alone in person is hard enough.

Dave Martell
04-24-2012, 01:21 PM
@Halicon - is any of this that you're talking about appear to you as an issue or are you just being nit picky? I'm asking because even though I too can see little things I don't see any issues worth mentioning.

Halicon
04-24-2012, 01:37 PM
Dave, that is an excellent question!

These are extremely small details barely visible to the eye. For anyone except another professional polisher it would indeed be nickpicking (but it still affects the performance quite readily, it's just beyond or right at the level of our eyesight so it's easy for us to disregard) be more or less impossible to make out and that's in many cases the way it remains if you take very polished knives for example such as Shigefusa. Few can really appreciate just how much work goes into such a craft and the accuracy that they polish to (it is so accurate!).

It isn't until one starts to really put demands on the edge that these small factors come into action. Kiri Daikou with an Usuba for example will have one throwing fits if it isn't a true flat both on hollow and front bevel, but with the proper polish it isn't too hard to take translucent shavings from a Daikou radish. Double bevel knives such as Gyuto, Santoku and so on that doesn't have only one bevel also don't really need such an accurate and perfect aesthetic polish as the two bevels when they join together creates a far thicker edge than what the finishers we use for single bevels can achieve. Especially western double-bevels are heavily limited by this (around 8-10k grit is the limit of the edge in the beefy western double bevel) but the Japanese tend to keep very low angles and thin blades to still get a very keen edge.

Now I really have to run, this turned out really interesting so I have to drag myself away. If anyone have any further questions I will be back in a few hours. :)

DK chef
04-24-2012, 01:43 PM
i love the result :D some great skills there. nice work

bieniek
04-24-2012, 01:47 PM
Both of you guys, I would love to hear about all the small issues. If Jon also could join it, it would be great.

I really like to get criticized, it motivates me to get better. Please, do it.

I tried hard to get better shot on back and the angle difference in front. Those are my best efforts.

http://i107.photobucket.com/albums/m310/carl00s/choil.png

http://i107.photobucket.com/albums/m310/carl00s/100_3946.jpg

http://i107.photobucket.com/albums/m310/carl00s/100_3945.jpg

Dave Martell
04-24-2012, 01:51 PM
No criticisms from me and in fact other than just talk about different finishes (etc) I have nothing to say besides for a repair of this size this looks great.

JBroida
04-24-2012, 02:11 PM
yeah... looks just fine to me. I would not have done as crazy of a primary cutting edge for my own knives, but i really understand where you are coming from on this. If you wanted, you could do a bit more on the ura, but you can also just try it and see how it holds up. Also, be careful not to flatten out the profile too much overtime.

This is more just for general information for people reading:
When sharpening single bevel knives, the idea is that you move the shinogi line up at the same rate you move the edge up. This maintains the geometry of the knife over time. If you want to strengthen the edge (as was done here), this can be temporarily ignored. But usually thats the way things are done. Also, the shinogi line should stay parallel to the edge (and visa versa).

maxim
04-24-2012, 02:11 PM
Looks also great to me ! Nice work on ura and i think its good that you dont waist a lot of steel specially for a deba. On the micro-bevel or bevel, do what you think is best for you it is your knife and you going to use it, so do what you think is most comfortable :D

Halicon
04-24-2012, 03:01 PM
No criticisms from me and in fact other than just talk about different finishes (etc) I have nothing to say besides for a repair of this size this looks great.

We discussed the geometry and it's accuracy, not the finish. The finish is from the fingerstones, the process we had up was still while working on the stones. The manner of which I described how to establish a back is in order to make the knife last as long as possible and perform to it's full capacity. Visually things might look just fine on that knife but when it's time for the stone one will have to compensate for it all. In the end one might even end up adding harm to the knife while resharpening if the geometry and surface on the blade wasn't accurate when first restored.

Especially when the knives go out to people I know haven't practiced on the stones for a long time, having everything perfectly set up helps educate the client in how a blade should be restored and polished as well as make it easier for the user to sharpen it.

Dave Martell
04-24-2012, 04:09 PM
Halicon, are you a professional knife sharpener or a professional sword polisher?

schanop
04-24-2012, 04:38 PM
Schanop, If you have a king its possible to make it darker and not mirrored. But I dont have it anymore, and the effect from binsui or JNS 1K alone isnt too good lookin.


Whoopse, sorry for the misunderstanding. I was referring to the body finish, your bevel finish is nicely done :-) I've got a hide kensaki yanagi with mirror finish, and now wish I had ordered it with the normal finish now knowing that their normal satin finish is so fine and nice. Next knife, perhaps.

schanop
04-24-2012, 04:52 PM
This is more just for general information for people reading:
When sharpening single bevel knives, the idea is that you move the shinogi line up at the same rate you move the edge up. This maintains the geometry of the knife over time. If you want to strengthen the edge (as was done here), this can be temporarily ignored. But usually thats the way things are done. Also, the shinogi line should stay parallel to the edge (and visa versa).

Jon, could you please elaborate a little bit more about shinogi line being parallel to the edge in the case of a deba (since this is a thread about a deba)?

Most pictures that I have seen and a couple of debas passing through my hand kinda tell me that, they usually come with smaller bevel and higher angle at the heel, and slightly wider bevel and lower angle at the tip.

Even taking into account that the tip is always thinner, quite often this does not always translate -- at least visual looking straight down to the side of the knife -- into parallel shinogi line and the edge?

Hopefully, this come out right in words.

Halicon
04-24-2012, 04:55 PM
Halicon, are you a professional knife sharpener or a professional sword polisher?

I wish I was the latter but at the point I am in my career I can't really be picky as there are still plenty of stones and tools I need in order to polish properly and match the steel of the sword to the stone.

It also seems like chefs like really sharp knives as well, who would have known?! :lol2:

To be serious however, very few, especially westerners that don't apprentice in Japan can reliably eat from polishing swords unless they are very famous and have already proved their skills to the connoiseur collectors in the world. So while I sharpen and polish pretty much anything I can reach with a stone, the sword polishing is really more of a goal of mine and a rare treat that I savor when I get the rare request to restore or polish a sword.

Strange that you bring this up here however, I don't recall mentioning that I polish swords in this kitchen knife section? Apologies if I did, it would have been quite a bit off-topic.

bieniek
04-24-2012, 05:00 PM
The manner of which I described how to establish a back is in order to make the knife last as long as possible and perform to it's full capacity.

And how would that look like?

Andrew H
04-24-2012, 05:07 PM
Jon, could you please elaborate a little bit more about shinogi line being parallel to the edge in the case of a deba (since this is a thread about a deba)?

Most pictures that I have seen and a couple of debas passing through my hand kinda tell me that, they usually come with smaller bevel and higher angle at the heel, and slightly wider bevel and lower angle at the tip.

Even taking into account that the tip is always thinner, quite often this does not always translate -- at least visual looking straight down to the side of the knife -- into parallel shinogi line and the edge?

Hopefully, this come out right in words.

I think what Jon is trying to say, forgive me if I misinterpreted, is that if you pick a point on the shinogi line and a corresponding point on the edge they should have the same 'slope' if you will. It's hard to explain without a picture.
What I'm trying to say is if the shinogi line is dead straight, the edge should be also. If the shinogi line has a gentle curve upwards the edge below it should have a gentle curve upwards. Someone please correct me where I'm wrong.

Halicon
04-24-2012, 05:08 PM
And how would that look like?

Just google for ito-ura. It is in general referred mostly to woodworking tools but any hollow blade performs the best with an Ito-ura hollow. Basically it means that the contacting flat that makes the cutting edge shouldn't be thicker than a thread.
http://kskdesign.com.au/blog/files/blade.jpg

This is a Japanese plane blade but was the fastest picture of Ito-ura I could find. The left side of the back is a bit overground so the Ito-ura isn't entirely uniform but I hope it helps give you an idea of what it looks like anyway.

bieniek
04-24-2012, 05:10 PM
yeah, if before sharpening at the heel you have from shinogi line to edge 10mm, after sharpening you should have there 10, not 9.5 or 10.5.
If on the tip area you pick a spot where there is 15 mm from shinogi to edge before sharpening, after session it should be 15.

etc

bieniek
04-24-2012, 05:14 PM
Just google for ito-ura. It is in general referred mostly to woodworking tools but any hollow blade performs the best with an Ito-ura hollow. Basically it means that the contacting flat that makes the cutting edge shouldn't be thicker than a thread.
http://kskdesign.com.au/blog/files/blade.jpg

This is a Japanese plane blade but was the fastest picture of Ito-ura I could find. The left side of the back is a bit overground so the Ito-ura isn't entirely uniform but I hope it helps give you an idea of what it looks like anyway.

Well, OK, it wasnt thicker than a thread before chipping action.

I also found that,
http://kskdesign.com.au/blog/files/ito_ura_problems.html

And I think it only applies to a perfect ground back side. If there is any bumps or hills, the grind will look uneven.
Guess its much easier on woodworking tool, where the edge is 40mm, not 330. Or is it?

Halicon
04-24-2012, 05:41 PM
It's actually much harder on a woodworking tool as the steel is much harder and is delivered unsharpened from the smith. What you linked to is also an issue that has been fixed by science as current planes are most often warped nowadays and not in need of Uradashi - this is quite off-topic however so I would prefer if we don't head into this area.

I don't understand quite what you mean with perfectly ground backside? Are you upset about what I have said in your thread? In no way did I mean that you should change anything to your knife, maybe your next, maybe keep it in mind or disregard it entirely. I get the feeling that you dislike my comments about your polish (which is good!) but just like with everything else there can always be improvements.

Myself I utterly destroyed the hollows of a couple of knives, Kiridashi, Kogatana, Kuri-Kogatana and numerous chisels until I was taught the proper way how to remove as little from the back as possible yet get the most out of it. You have to understand that a kitchen knife isn't smacked at with a hammer like a plane blade during the Uradashi - that is most certainly an area where such a fine edge can suffer damage but that's soft steel landing directly against the craft with force.

A hollow is established using a tool called "Sen". It is basically a piece of steel harder than the steel with a convex edge that takes small shavings out of the knife, tool or what it now might be. It isn't done by grinding as the process is too inaccurate and us sharpeners would have to remove way too much steel to get an accurate flat if that was what they used (like unsharpened traditional tools for example). After that it is up to the user and how he works with the hollow that decides what will happen to it.

Please do not worry about Ito-ura chipping for knives. Plane blades are a completely different creature and can't really be compared in that sense. The cutting action against wood stresses the serrations quite a lot more than in the case of a knife against organic material. And in the case of an Ito-ura, one simply has to place the entire back fully flat on the finisher and run it until the back is sharp again which is very welcome when you are rushed. No real pressure needed anywhere, just keep the blade flat on the stone and stabilize the tip with a finger so that it doesn't rock on the pulling stroke.

TB_London
04-24-2012, 06:07 PM
I don't think that anyone is in any way upset with anything you are saying, we're just spread all over the world with a lot of language barriers.


l I was taught the proper way how to remove as little from the back as possible yet get the most out of it. .
It would be really interesting for you to describe the proper way that you were taught, I'm keen to learn more to improve my technique, as are others I'm sure.

Halicon
04-24-2012, 06:31 PM
TB_London, indeed. I just had a feeling but then again that's just that and is entirely on my end.


I have a project coming up that I will try to document and show. At the moment I don't have a step-by-step guide how to do it however but hopefully in a few weeks I will. The process is very precise and require dead-flat stones, it's also especially important the way one puts pressure only on the lamination steel and not the Jigane. The pressure has to be focused very solidly there and when Ito-ura is near completion it isn't uncommon for me to shave off a layer of skin on my index finger as I put the force from the lamination and "outside the edge" - all to reduce the pressure you put on the spine while you remove material of the flat near the edge to reduce it in size.

TB_London
04-24-2012, 07:13 PM
A step by step would be great, looking forward to it :D
Thanks,
Tom

memorael
04-24-2012, 11:05 PM
TB_London, indeed. I just had a feeling but then again that's just that and is entirely on my end.


I have a project coming up that I will try to document and show. At the moment I don't have a step-by-step guide how to do it however but hopefully in a few weeks I will. The process is very precise and require dead-flat stones, it's also especially important the way one puts pressure only on the lamination steel and not the Jigane. The pressure has to be focused very solidly there and when Ito-ura is near completion it isn't uncommon for me to shave off a layer of skin on my index finger as I put the force from the lamination and "outside the edge" - all to reduce the pressure you put on the spine while you remove material of the flat near the edge to reduce it in size.

I don't think anyone here is upset at anything you have said. I for one can tell you that I am real happy you showed up, seems like your a very knowledgeable person and would really appreciate a video or WIP on how to properly sharpen a WA style knife. I have had people explain it to me a lot of times and have a sorta clue how to do it, but really I am far from being proficient. Thanks for your comments and explanations!

JBroida
04-24-2012, 11:31 PM
A hollow is established using a tool called "Sen". It is basically a piece of steel harder than the steel with a convex edge that takes small shavings out of the knife, tool or what it now might be. It isn't done by grinding as the process is too inaccurate and us sharpeners would have to remove way too much steel to get an accurate flat if that was what they used (like unsharpened traditional tools for example). After that it is up to the user and how he works with the hollow that decides what will happen to it.


This actually isnt true for most japanese kitchen knives... two makers come to mind that do this and one of them is Iizkua-san (shigefusa). The rest use a grinding wheel.

Sharpening kitchen knives is still very different than sharpening wood working tools, kiridashi, etc. While you dont want to oversharpen the back side of these knives, some sharpening initially will strengthen the edge and improve cutting performance. Once a well sharpened ura is established, its all about maintaining that and not removing too much metal.

I made a video on uraoshi sharpening a little while back:

http://www.youtube.com/watch?feature=player_detailpage&list=PLEBF55079F53216AB&v=cCY5CKkBers

Halicon
04-25-2012, 08:28 AM
Jbroida, I didn't want to put it into a definitive as people here might have a hard time to accept why only some knives receive the Sen treatment and the result of it. You must have missed that all high-end woodworking tools arrive unsharpened, no harm done. Yes they are two different creatures (tempering, refining, purity etc) but the back isn't, the important thing is where you put the pressure and how you force the flat to be produced.

The ura on a properly forged and finished Japanese knife differs only in the fact that woodworking blades often arrive with the Kuroichi skin still intact to protect the hollow. Why wouldn't Uraoshi on a woodworking knife and a kitchen knife be the same by the way? They were performed with the same tool? If it was used using a grinder, well that's a direct sign of lower quality and less finish.
Take Iwasaki-san for example, he has the Sen technique down to a science and puts almost ridiculously accurate hollows on his knives, woodworking knives only though, Mizuochi-san did the kitchen knives a long time ago with the approval of Iwasaki-san.

The Sen is a very accurate tool, extremely accurate even and it doesn't produce any heat. To put things plainly, a knife that was roughly ground and have an inaccurate hollow and on top of that doesn't have very great steel and quality to begin with I wouldn't spend the hours to polish, it's simply not worth it. That's only me though, I don't have the time anymore to spend on any type of crafts and have to choose what I accept to polish.

Uraoshi literally means the meeting of the back and the front; two angles coming together, it isn't actually flattening which is what we like to call it. But the process involves mating the back with the front bevel to produce one edge instead of two which happens if they don't meet properly.

I'm getting a bit confused here because you put emphasis on that the knife and woodworking knife is different, but I was taught that when I am grinding with my upper body on a plane blade, that's Uraoshi. When I'm flattening a chisel, that's Uraoshi. Only the shape of the hollow changes and it is up to the user how he wraps his mind around that particular type of hollow in order to refine it and bring it out as properly as possible which would be Ito-ura.

Schtoo
04-25-2012, 11:44 AM
You must have missed that all high-end woodworking tools arrive unsharpened, no harm done.

Are you sure?


Stu.

JBroida
04-25-2012, 12:04 PM
Jbroida, I didn't want to put it into a definitive as people here might have a hard time to accept why only some knives receive the Sen treatment and the result of it. You must have missed that all high-end woodworking tools arrive unsharpened, no harm done. Yes they are two different creatures (tempering, refining, purity etc) but the back isn't, the important thing is where you put the pressure and how you force the flat to be produced.

The ura on a properly forged and finished Japanese knife differs only in the fact that woodworking blades often arrive with the Kuroichi skin still intact to protect the hollow. Why wouldn't Uraoshi on a woodworking knife and a kitchen knife be the same by the way? They were performed with the same tool? If it was used using a grinder, well that's a direct sign of lower quality and less finish.
Take Iwasaki-san for example, he has the Sen technique down to a science and puts almost ridiculously accurate hollows on his knives, woodworking knives only though, Mizuochi-san did the kitchen knives a long time ago with the approval of Iwasaki-san.

The Sen is a very accurate tool, extremely accurate even and it doesn't produce any heat. To put things plainly, a knife that was roughly ground and have an inaccurate hollow and on top of that doesn't have very great steel and quality to begin with I wouldn't spend the hours to polish, it's simply not worth it. That's only me though, I don't have the time anymore to spend on any type of crafts and have to choose what I accept to polish.

Uraoshi literally means the meeting of the back and the front; two angles coming together, it isn't actually flattening which is what we like to call it. But the process involves mating the back with the front bevel to produce one edge instead of two which happens if they don't meet properly.

I'm getting a bit confused here because you put emphasis on that the knife and woodworking knife is different, but I was taught that when I am grinding with my upper body on a plane blade, that's Uraoshi. When I'm flattening a chisel, that's Uraoshi. Only the shape of the hollow changes and it is up to the user how he wraps his mind around that particular type of hollow in order to refine it and bring it out as properly as possible which would be Ito-ura.

for what its worth, uraoshi is a combination of ura (back) and osu (to push), which described in and of itself how uraoshi sharpening is to be done. Your scope of understanding is very limited and seems like you only have an understanding of a few Sanjo based makers (one of whom is retired). Just because a few people do something one way doesnt mean everyone does or should.

Wood working tools and kitchen knives are different... even though the way uraoshi is done can be similar, the emphasis and goal may be slightly different. This is why makers of wood working tools and makers of knives choose different stones among other things.

Halicon
04-25-2012, 12:44 PM
Pardon me if I'm being rude but you think only Iwasaki and Iizuka-san uses a Sen? Heiji is another smith that uses the Sen albeit not on the crafts geared towards the mid-end clients and where price becomes an issue.

The Sen is an old tool, a traditional tool that is used to create traditional Japanese kitchen knives, woodworking tools and even saws. For the Japanese it is a sign of high quality, that the smith took the long time it takes to use a Sen. You say that my scope is very limited - that's not the case. I believe it's your "scope" that is limited. All a Sen does is produce a more accurate hollow at the cost of more time and effort, that it is somehow only for woodworking tools or a select few is something I'm really struggling with.

To give a literal translation of Uraoshi, Ura = back. Oshi = pressure, push. The meaning of Uraoshi is in there like you say but again I fail to understand exactly where you're heading with this. The traditional way to create a hollow is with a Sen, it's the age-old method of theirs as they didn't have power tools when their swords were swung against their opponents in the warring states era.

What you bring up with using different stones for tools is also a view that is very "scoped" and limited. We like to use harder stones for tools as they are not only tempered to be much harder but also refined further than a knife and thus needs a stone that first of all cuts fast due to the harder steel but also is very accurate and doesn't wear fast as the hardness of the stone is in direct relation to the accuracy one can polish at - soft stones have a give of some 20-30 microns which makes them great for beginners as it covers mistakes to a degree. But in the case of a woodworking tool we want as little give as possible in order to have a full contact of the entire flat bevel so that we can reach the serrations at the edge evenly across the blade.

That smiths specializing in woodworking tools forges them with hard jnats in mind is almost preposterous, one can choose any stone but it's a question of the road you take to reach your goal that is the essence of jnats. Using a hard stone with the harder steel and demand for more accuracy is best solved by using a hard stone, that's as simple as it is and there's no further need to complicate things further than that.

I have to apologize but yet again I don't understand why you keep bringing this up as the Sen has been a traditional tool for hundreds of years in Japan. When doing Uraoshi on a woodworking blade, one places the entire back on the stone. When one does it on a kitchen knife, one places the entire back on the stone and push (Oshi) properly to bring the flats out and if done well you get Ito-ura.
Of course kitchen knives and woodworking tools are different but the nature of the Uraoshi isn't. One still has to think, observe and think again of how to bring the hollow out into as good of a flat as possible.

Halicon
04-25-2012, 12:50 PM
Looking at the great names such as Usui Kengo, yep they deliver them unsharpened and therefore at 80% of the price. There are a couple of few smiths such as Tasai that like to deliver their tools semi-finished, but you also end up paying for it.

mpukas
04-25-2012, 01:00 PM
Jon, could you please elaborate a little bit more about shinogi line being parallel to the edge in the case of a deba (since this is a thread about a deba)?

I've had conversations w/ Jon about this, and Jon, please correct me if I don't get this quite right...

What is meant by the shinogi line being parralllel to the edge means is that the bevel, hamaguri in the case of a single bevel knife, such as a deba in this case (and also applies to double bevel knives such as gyuto), will be the same width the entire length of the blade, from heel to tip. If at any point the bevel becomes wider or narrower, then the shinogi line is not parrallel to the edge. So, what does this mean? The angle of the bevel will change constantly in relation to the thickness of the knife at any given point, since there is a taper from handle to tip.

The intention behind this is that different parts of the knife are used for different tasks - the tip will have a steeper angle where the knife is thinnest, therefore sharper and more fragile, and is to be used for finer cutting such as slicing flesh. The heel will have a lower angle where the knife is thickest, therefore more robust, and can be used for more demanding tasks such as cutting through the spine of a fish to remove the head.

mpukas
04-25-2012, 01:05 PM
This is more just for general information for people reading:
When sharpening single bevel knives, the idea is that you move the shinogi line up at the same rate you move the edge up. This maintains the geometry of the knife over time. If you want to strengthen the edge (as was done here), this can be temporarily ignored. But usually thats the way things are done. Also, the shinogi line should stay parallel to the edge (and visa versa).

Jon - I've got a question - what happens to the edge bevel on the back side as the edge gets raised closer and closer to the spine due to sharpening over time? Due to the concave back side, and keeping the edge bevel on the backside the same width, it seems to me that as the edge rises with each sharpening, the edge will move slightly to the right in relation to the center-line of the spine. Is this accurate, how is it addressed, and does it matter? Thanks much! mpp

JBroida
04-25-2012, 01:36 PM
Jon - I've got a question - what happens to the edge bevel on the back side as the edge gets raised closer and closer to the spine due to sharpening over time? Due to the concave back side, and keeping the edge bevel on the backside the same width, it seems to me that as the edge rises with each sharpening, the edge will move slightly to the right in relation to the center-line of the spine. Is this accurate, how is it addressed, and does it matter? Thanks much! mpp

6486

bieniek
04-25-2012, 01:37 PM
I don't understand quite what you mean with perfectly ground backside?

I mean, the polishing there might be straight, but the surface of the concave-hollow not. It can vary in depth so to speak. What then?

Come on, im pro chef and I dont get personal about anything else than insulting women :) But maybe my londoner-English is "over kitcheny".

What I meant on the comment about a chisel vs kitchen knife.
Imagine, you have a chisel which is 33cm wide or even 54 [yeah] - How big of a stone would you need to put the back flat on it all at once?

Ive never seen anybody doing that on a kitchen knife. Or am I misunderstanding?

JBroida
04-25-2012, 01:46 PM
Pardon me if I'm being rude but you think only Iwasaki and Iizuka-san uses a Sen? Heiji is another smith that uses the Sen albeit not on the crafts geared towards the mid-end clients and where price becomes an issue.

The Sen is an old tool, a traditional tool that is used to create traditional Japanese kitchen knives, woodworking tools and even saws. For the Japanese it is a sign of high quality, that the smith took the long time it takes to use a Sen. You say that my scope is very limited - that's not the case. I believe it's your "scope" that is limited. All a Sen does is produce a more accurate hollow at the cost of more time and effort, that it is somehow only for woodworking tools or a select few is something I'm really struggling with.

To give a literal translation of Uraoshi, Ura = back. Oshi = pressure, push. The meaning of Uraoshi is in there like you say but again I fail to understand exactly where you're heading with this. The traditional way to create a hollow is with a Sen, it's the age-old method of theirs as they didn't have power tools when their swords were swung against their opponents in the warring states era.

What you bring up with using different stones for tools is also a view that is very "scoped" and limited. We like to use harder stones for tools as they are not only tempered to be much harder but also refined further than a knife and thus needs a stone that first of all cuts fast due to the harder steel but also is very accurate and doesn't wear fast as the hardness of the stone is in direct relation to the accuracy one can polish at - soft stones have a give of some 20-30 microns which makes them great for beginners as it covers mistakes to a degree. But in the case of a woodworking tool we want as little give as possible in order to have a full contact of the entire flat bevel so that we can reach the serrations at the edge evenly across the blade.

That smiths specializing in woodworking tools forges them with hard jnats in mind is almost preposterous, one can choose any stone but it's a question of the road you take to reach your goal that is the essence of jnats. Using a hard stone with the harder steel and demand for more accuracy is best solved by using a hard stone, that's as simple as it is and there's no further need to complicate things further than that.

I have to apologize but yet again I don't understand why you keep bringing this up as the Sen has been a traditional tool for hundreds of years in Japan. When doing Uraoshi on a woodworking blade, one places the entire back on the stone. When one does it on a kitchen knife, one places the entire back on the stone and push (Oshi) properly to bring the flats out and if done well you get Ito-ura.
Of course kitchen knives and woodworking tools are different but the nature of the Uraoshi isn't. One still has to think, observe and think again of how to bring the hollow out into as good of a flat as possible.

there are a number of books, videos, etc. in Japan (in japanese) that agree with what i am saying... in addition, i am there every year training with the craftsmen in japan... i'm in workshops with people like Iizuka-san, Iwasaki-san, Nakaya Heiji, and a number of people in regions, such as sakai, tosa, tokyo, sanjo, ibaraki, etc. I feel very comfortable with what i have said.

FYI, Ito-Ura only refers to something desirable for Kanna (not even for nomi)

mpukas
04-25-2012, 02:01 PM
6486

Of course. Duh. Thnx!

Schtoo
04-25-2012, 02:19 PM
Looking at the great names such as Usui Kengo, yep they deliver them unsharpened and therefore at 80% of the price. There are a couple of few smiths such as Tasai that like to deliver their tools semi-finished, but you also end up paying for it.

Are you really sure?

Stu.

(Finds stuff out by picking up the phone or sending an email to the folks who make the stuff. I don't know what anyone else does, but that's what I do. ;) )

Halicon
04-25-2012, 02:20 PM
there are a number of books, videos, etc. in Japan (in japanese) that agree with what i am saying... in addition, i am there every year training with the craftsmen in japan... i'm in workshops with people like Iizuka-san, Iwasaki-san, Nakaya Heiji, and a number of people in regions, such as sakai, tosa, tokyo, sanjo, ibaraki, etc. I feel very comfortable with what i have said.

FYI, Ito-Ura only refers to something desirable for Kanna (not even for nomi)

That's great for you JBroida.

I am in all earnest baffled that you haven't heard of Ito-ura earlier or the history of the Sen in Japan. It's good that you have solid sources such as Iwasaki-san, Iizuka-san, Heiji-san and greats like that to guide you on your way though, you're in good hands.

I also feel very comfortable with what I have said, why wouldn't either of us? It isn't a contest of who knows more or who is the best, or aren't we here to seek knowledge but instead come with ulterior motives? I won't budge on what I have written and explained and you won't budge on what you have written so I really don't see why you keep bringing this up as the both of us will only stray further off-topic the more we keep going.



@Bieniek, indeed it requires a bit of compensating from the user and usually larger stones are preferred. This whole topic is a bit sketchy to cover by writing on top of also being hard to wrapp your head around, and I'm very busy currently with a project.
I would love to demonstrate later on when I get the time though so please stay tuned.

mhlee
04-25-2012, 05:03 PM
Are you really sure?

Stu.

(Finds stuff out by picking up the phone or sending an email to the folks who make the stuff. I don't know what anyone else does, but that's what I do. ;) )

I always like seeing what Stu writes.

Dave Martell
04-25-2012, 05:11 PM
All I know is that we can find a lot of information on knifemakers using wheels to hollow grind and only one (maybe two) makers who use a sen. I think it's important to stay on track with kitchen knife talk vs plane blade/chisel/sword talk.

Furthermore, knife maintainers (also known as knife users) are NEVER going to use a sen or a wheel to re-create the hollow of their knives - it'll NEVER happen. Sure we can talk about the how & why a sen or wheel is used but let's not refer to these aspects as critical to maintenance or as a recommendation for fixing or maintaining these knives because that's misleading. Now I'm not saying that anyone has said these things, I'm simply stating the above because the waters are getting murky in here.

schanop
04-25-2012, 05:54 PM
http://www.kitchenknifeforums.com/attachment.php?attachmentid=6486

Picture describes it more clearly than words :-) @mpukas, I think I understand what you try to describe.

May be I should have phrased my question as that some knives come from the make with wider bevel and lower angle at the tip like many debas and shigefusa yanagibas. If the intention is to follow maker's shape (I think that was what Jon was saying) during sharpening and usage, that's all ok.



I've had conversations w/ Jon about this, and Jon, please correct me if I don't get this quite right...

What is meant by the shinogi line being parralllel to the edge means is that the bevel, hamaguri in the case of a single bevel knife, such as a deba in this case (and also applies to double bevel knives such as gyuto), will be the same width the entire length of the blade, from heel to tip. If at any point the bevel becomes wider or narrower, then the shinogi line is not parrallel to the edge. So, what does this mean? The angle of the bevel will change constantly in relation to the thickness of the knife at any given point, since there is a taper from handle to tip.

The intention behind this is that different parts of the knife are used for different tasks - the tip will have a steeper angle where the knife is thinnest, therefore sharper and more fragile, and is to be used for finer cutting such as slicing flesh. The heel will have a lower angle where the knife is thickest, therefore more robust, and can be used for more demanding tasks such as cutting through the spine of a fish to remove the head.


6486

mpukas
04-26-2012, 12:14 AM
Picture describes it more clearly than words :-) @mpukas, I think I understand what you try to describe.

Yeah, that pic is worth more than 1,000 of my words. I'm trying to reiterate in my own words what Jon has told me. I certainly don't know it first hand (yet). But I'll say it again, as Jon told me, as has been told to him by his teachers - the sharpeners he's trained with go for a bevel of a constant width along the entire edge that's parallel to the edge. And that means that's the bevel angle changes along the entire edge as the blade tapers from heel to tip.

Schtoo
04-26-2012, 02:08 AM
All I know is that we can find a lot of information on knifemakers using wheels to hollow grind and only one (maybe two) makers who use a sen. I think it's important to stay on track with kitchen knife talk vs plane blade/chisel/sword talk.



Hey, leave me out of this!

Of the folks I know making tools, I know of one who routinely uses a sen, and he makes saws.

When I'm face to face with a few of them (a couple months I think at the moment) I'll ask and see who, of the chisel and plane makers, actually uses a sen.

I kind of wonder how effective a sen can be on steel that's at the upper limits of it's hardness anyway. Saws are not so hard and sen are still commonly used to hollow and thickness the saw plates on the very high end saws.

Sen are great tools in the right hands, but I can't imagine they're useful for anyone but professionals doing things in the old ways for a specific reason. Especially since the makers of tools who are still working (and making a living) predominantly use grind stones to form hollows.

But what do I know?

Stu.

schanop
04-26-2012, 02:16 AM
Yeah, that pic is worth more than 1,000 of my words. I'm trying to reiterate in my own words what Jon has told me. I certainly don't know it first hand (yet). But I'll say it again, as Jon told me, as has been told to him by his teachers - the sharpeners he's trained with go for a bevel of a constant width along the entire edge that's parallel to the edge. And that means that's the bevel angle changes along the entire edge as the blade tapers from heel to tip.

Totally understand what you are saying mpukas. It just that there are some knives the bevel width is not quite constant. Let's use this hide ko deba for another example, and please excuse my rough science:
http://img441.imageshack.us/img441/1117/bevelwidth.jpg

Bevel is still pretty pristine, been to the stone once only and mainly with the extra coarse reddish akapin from maksim.

May be it is just a nitpicking on my behalf for a couple of mm. difference between heel and tip.

JBroida
04-26-2012, 02:22 AM
close enough for government work ;)

same concept though... heel for heavy work and tip for delicate

Sarge
04-26-2012, 11:34 AM
Totally understand what you are saying mpukas. It just that there are some knives the bevel width is not quite constant. Let's use this hide ko deba for another example, and please excuse my rough science:
http://img441.imageshack.us/img441/1117/bevelwidth.jpg

Bevel is still pretty pristine, been to the stone once only and mainly with the extra coarse reddish akapin from maksim.

May be it is just a nitpicking on my behalf for a couple of mm. difference between heel and tip.

Notice though that where the shinogi line curves up is where the edge begins to curve up also. The thing you want to avoid is creating a flatter section along that curve. So the ability to follow the curve when sharpening is important. It isn't that the bevel maintains the same width, but where the shinogi line curves or stays straight the edge should follow that curve or straightness.

The bevel width (and if I'm wrong please correct me) is as someone said a function of the angle being used.

bieniek
10-06-2012, 01:43 AM
You want mamma mia? I'll give ya mamma mia! :lol2:

http://www.kitchenknifeforums.com/attachment.php?attachmentid=6381&d=1335239882

http://www.kitchenknifeforums.com/attachment.php?attachmentid=6380&d=1335239874

Mamma mia wars!!

http://imageshack.us/a/img689/791/zdjcie0352b.jpg
http://imageshack.us/a/img23/5826/zdjcie0351u.jpg

Sorry for the quality. pics with my old nokia

Next contender up! Brand new 210 yoshiaki fujiwara.

http://imageshack.us/a/img171/8045/1005196q.jpg
http://imageshack.us/a/img99/4051/1005195v.jpg

Andrew H
10-06-2012, 01:57 AM
What happened to that Kato?!

chinacats
10-06-2012, 02:39 AM
:dazed:

markenki
10-06-2012, 02:51 AM
What happened to that Kato?!
+1

Cutty Sharp
10-06-2012, 03:05 AM
Could it mean ... the magnificent Kato has finally revealed a flaw? :what:

bieniek
10-06-2012, 03:47 AM
Never seen and not expect to see a japanese knife hardened to steels limits and withstanding bone cutting activities.

As usual, amateur [no beefing, just a fact to note] usage plus knife for advanced users = disaster.

As I said in review, at the end of the day its just a knife, made of tough steel. Luckily cladded.

chuck239
10-06-2012, 04:40 AM
Never seen and not expect to see a japanese knife hardened to steels limits and withstanding bone cutting activities.

As usual, amateur [no beefing, just a fact to note] usage plus knife for advanced users = disaster.

As I said in review, at the end of the day its just a knife, made of tough steel. Luckily cladded.

Had the Kato not been sharpened? When I first got mine I cut through a few whole roasted chickens while making staff meal. Needless to say after going through the small rib bones and the joints of the legs, the edge looks similar to that (not quite as bad.) I then sharpened it and tried it again the next day and had zero chipping. So, I will say it might just be the initial edge is pretty week.

The experience made me feel like I would not recommend the knife to anyone who isn't comfortable with sharpening because I was initially very disappointed that the edge being so fragile.

-Chuck

Von blewitt
10-06-2012, 07:20 AM
Had the Kato not been sharpened? When I first got mine I cut through a few whole roasted chickens while making staff meal. Needless to say after going through the small rib bones and the joints of the legs, the edge looks similar to that (not quite as bad.) I then sharpened it and tried it again the next day and had zero chipping. So, I will say it might just be the initial edge is pretty week.

The experience made me feel like I would not recommend the knife to anyone who isn't comfortable with sharpening because I was initially very disappointed that the edge being so fragile.

-Chuck
I had the exact same thing happen with my 270 kato gyuto! So when I got my kato suji first thing I did was take it to the stones, I've had no issues with either since.

heirkb
10-06-2012, 11:48 AM
Wow, these knives are sounding more and more like Heijis. From the description of cutting (as compared to Shig, for example), to being fat but thin behind the edge, to being very fragile OOTB.

maxim
10-06-2012, 12:56 PM
Thanks for feedback guys !! I will look in to it when I get home and try to ship Katos only fully sharpend by me :)
As I sell those knives I thought it went only for pro ussers with bunch of stones and experience in Japanese knives but it seems like they get really popular for regular home chefs too

My mistake and I will take care of it


Had the Kato not been sharpened? When I first got mine I cut through a few whole roasted chickens while making staff meal. Needless to say after going through the small rib bones and the joints of the legs, the edge looks similar to that (not quite as bad.) I then sharpened it and tried it again the next day and had zero chipping. So, I will say it might just be the initial edge is pretty week.

The experience made me feel like I would not recommend the knife to anyone who isn't comfortable with sharpening because I was initially very disappointed that the edge being so fragile.

-Chuck

chuck239
10-06-2012, 02:03 PM
Thanks for feedback guys !! I will look in to it when I get home and try to ship Katos only fully sharpend by me :)
As I sell those knives I thought it went only for pro ussers with bunch of stones and experience in Japanese knives but it seems like they get really popular for regular home chefs too

My mistake and I will take care of it

Maxim,

I am a pro but when I first got it it felt sharp and I had it shipped to work so I just started using it. It wasn't an issue for me to fix. I am just saying if someone wasn't confident sharpening a knife I wouldn't suggest buyin this knife unless paying for it to be sharpened. I think sharpening them would be a great idea to hopefully solve that little issue.

-Chuck

mainaman
10-10-2012, 07:18 AM
Could it mean ... the magnificent Kato has finally revealed a flaw? :what:
are you serious? The knife is unbreakable until someone decided to hack wood with it ..

mainaman
10-10-2012, 07:19 AM
Wow, these knives are sounding more and more like Heijis. From the description of cutting (as compared to Shig, for example), to being fat but thin behind the edge, to being very fragile OOTB.
the geometry is very different, then do not have flats on the blade surface.

mainaman
10-10-2012, 07:21 AM
Maxim,

I am a pro but when I first got it it felt sharp and I had it shipped to work so I just started using it. It wasn't an issue for me to fix. I am just saying if someone wasn't confident sharpening a knife I wouldn't suggest buyin this knife unless paying for it to be sharpened. I think sharpening them would be a great idea to hopefully solve that little issue.

-Chuck
Have you tried other guytos on chickens the same way? How did they fare?

chuck239
10-10-2012, 07:45 PM
Have you tried other guytos on chickens the same way? How did they fare?

Yes, I have used just about every other knife I own to do this task. It is a very common thing for me at work. This was the worst I have ever seen a knife handle the task. It was with the edge that came on he knife. That night I sharpened it to fix all of the large chips and I have had not had any chipping since. I own about 35 other gyutos as a reference.

-Chuck

bieniek
10-11-2012, 12:46 PM
How many of these are honyakis?

One thing is for sure, it is able to get wild sharp and hold it very long while. Its quite clear how japanese maker attains that. When I got Shigefusa I stayed far away from bones yet I chipped it.

chuck239
10-11-2012, 06:27 PM
2 of the knives are true honyaki. But, the Kato is not. It does get very sharp and seems to hold an edge well. I have not been using mine a ton because there is another issue I need to get resolved (not serious)

-Chuck

bieniek
10-12-2012, 05:45 PM
So youve been bashing chicken bones with them, and there was no squeaking?

My mate broke off a heel on mine today.

chuck239
10-12-2012, 06:10 PM
So youve been bashing chicken bones with them, and there was no squeaking?

My mate broke off a heel on mine today.

I am sorry that you don't like someone said something not perfect about a knife sold by your friend. I do like the knife minus a few things. All I am saying is the initial OUT OF THE BOX edge was fragile and chipped very easily.

I never said I was "bashing chicken bones", so please don't pass judgement (I have not made comments on some of your posts). If a gyuto can not cut through rib bones on a 3-3.5# chicken without chipping severely, there is probably an issue with the edge. Yes, I have cut through the rib cages of chickens with almost every knife I own. I have resharpened the knife and did not have issues with chipping the next 2 days I used it at work. Since then I have had to stop using it because it came with a loose handle and I do not feel comfortable using it until I have a chance to fix that.

-Chuck

maxim
10-12-2012, 06:53 PM
wow guys chill hehe

It is a Knife :D Not a knife to cut true bones, when i brake down the chicken i do not cut true any bone, for bones i have special knives, so thats why i assumed all that brake down the chickens dont do that and i was wrong sorry for that and i will change that in the description.
But i believe that all have to change they edge to they preference when they get so expensive knives anyway, if you use it for hard or delicate cuts etc.

Chuck: I am sorry for loos handle but i check all knives before they go out and maybe with climate change or postage something got wrong. But it is easy fix, just tap your handle on the cutting bord while holding on handle and that should be fixed :)

chuck239
10-12-2012, 07:16 PM
Hey Maxim,

I tried that with the handle the first day when I noticed but it came loose again. I am just going to take it to Jon's when he gets back and have him rehandle it (if he will). The knife has no problems cutting through small rib bones on a chicken (after sharpening), I have not had a knife that can not complete this task. All I am trying to say was that the initial OOTB edge is fragile. The knife is a good performer and I plan on doing some comparisons with it. I know some people are scared to use a knife to cut through things but these bones are about as tough as cutting through a salmon, plus the chickens are already roasted so the bones are even more delicate. I am not smashing through leg bones or something.

Sorry if anyone is upset that I am using the knife for basic tasks at work for me. I will say just as a reference: Martell, Ealy, Harner, Burke, Rader, Kramer, Devin, Tillman, Mario, Pierre, ginga honyaki, hide honyaki, hide, heiji, kochi, zakuri, gengetsu, zdp189, blazen, nenox, suisen, mizuno, shigefusa, ect have all done this as well (and will continue to do it)....

-Chuck

maxim
10-12-2012, 07:29 PM
Just tap bit harder it will be fine :) As long you only hold it on handle
But i am sure Jon can fix it, if he dont have time you are always welcome to send it back and i fix it for you :)

I understand what you saying but i think some people will misunderstand and think they can cut true all thick bones.

mainaman
10-12-2012, 07:37 PM
Hey Maxim,

I tried that with the handle the first day when I noticed but it came loose again. I am just going to take it to Jon's when he gets back and have him rehandle it (if he will). The knife has no problems cutting through small rib bones on a chicken (after sharpening), I have not had a knife that can not complete this task. All I am trying to say was that the initial OOTB edge is fragile. The knife is a good performer and I plan on doing some comparisons with it. I know some people are scared to use a knife to cut through things but these bones are about as tough as cutting through a salmon, plus the chickens are already roasted so the bones are even more delicate. I am not smashing through leg bones or something.

Sorry if anyone is upset that I am using the knife for basic tasks at work for me. I will say just as a reference: Martell, Ealy, Harner, Burke, Rader, Kramer, Devin, Tillman, Mario, Pierre, ginga honyaki, hide honyaki, hide, heiji, kochi, zakuri, gengetsu, zdp189, blazen, nenox, suisen, mizuno, shigefusa, ect have all done this as well (and will continue to do it)....

-Chuck
have you tried to epoxy the handle? As for the shipping after you redid the edge did you try it on chickens again?

phan1
10-13-2012, 02:00 AM
I've used about 3 deba in my life professionally, and I can say I have chipped every one of them just from using it on fish, its intended purpose. They all chipped in the beginning, and each sharpening session I kept raising the angle until it stops chipping, simple as that. I know it's not common sense that a knife should be purposely chipped and beaten up until the user can find its "sweetspot" angle where the blade no longer chips, but that's just the way it's done.

maxim
10-13-2012, 04:05 AM
I have always thought that it is easer to raise angle then thin it out :2cents:

maxim
10-13-2012, 08:55 AM
Also here is the video how to attach and remove handle

Remove
http://www.youtube.com/watch?feature=player_detailpage&v=6evDu8cjRps#t=4s

Attach
http://www.youtube.com/watch?feature=player_detailpage&v=6evDu8cjRps#t=2270s

haha very old video but i still du it same way just with better hammer and wooden stick :D

bieniek
10-13-2012, 12:43 PM
I am sorry that you don't like someone said something not perfect about a knife sold by your friend. I do like the knife minus a few things. All I am saying is the initial OUT OF THE BOX edge was fragile and chipped very easily.
-Chuck

The knife was sold by a seller to me. When he became[or if] a friend is a different story but I can assure you when it comes to money I wouldnt like to get a crap product for this price, nor I expected more.

Essentially we are saying same thing apart from I chipped the factory edge on oxtails. Then to one chip came two other in same spot. All is in the review.
But before I start to pick on the maker or his edge I understand he have million times more experience than me, so if his edge chips, that means its my technique that is a problem here.
Never tried a shig on any bone just because those knives serve another purpose for me, just like I would change cutting board for the purpose.



I never said I was "bashing chicken bones", so please don't pass judgement (I have not made comments on some of your posts).
-Chuck

You are more than welcome to do so, Ill take it on my chest, so to speak. We talk in this subject about bone cutting activities.
I did on oxtails, but for me chicken is more tricky. Cause on small bones if you twist the knife while the edge sits in the bone. But thats just me.

Oh and BTW never chipped deba - not mentioning the broken tip, and I use it a lot and literally chop bones with it.