That's a Yoshikane likely in SKD. Super thin edges. Typically hardened to 63-64 HRC so making the angle steeper than normal is a good idea to maintain the performance. I have the 270mm gyuto version and it is beast of a laser.
Thanks for your comment. I can't read Japanese so have no idea what it is or what it's made of. With these I like to take the lightest touch possible and use a low angle to maintain it's ability to be very sharp. Customer was happy and says it's now a lot sharper than when new.
Baz, always a pleasure to watch you working with your good old T8. By the way, I am also a big fan of beginning with the tip and end towards the handle to achieve a very regular bevel. I am still wondering why you do not do a "guided" de-burring using a support bar. I always fear to round of the apex to much when de-buring free-hand. Of course I can perfectly see, that you have very controlled hand movement as a former welder :-)) On my T8 I am using the extended universal support US 430 to grind and the original shorter support in combination with the MB-102 Multi Base. Using that one helps, because the black fixation screw of the knife jig does not bump into the „leg“ of the support rail. Other than that for some 3-layer Japanese knives (HRC 63) , I felt to give the SJ 250 another try, and guess what: doing extremely light alternating passes towards the end of the grind and then guided honing revealed a stellar result. No bess test results I can share, but paper tests all passed nicely and extremely smooth…. Maybe the SJ 250 is only good for high hardness steels??? Greetings again from very rainy Zurich, Felix
Such an interesting system. I only use Japanese wetstones to sharpen all my knives, super interesting how you can change the grit with different plates, I'm slightly confused tho because I use diamond plates on my stones to flatten them every time, but my stones don't change grits like this system does. Very cool, cheers.
The Tormek system is based on the traditional fixed stone system but instead the wheel rotates in a water trough for an added industrialised aspect and has a guided rail system to keep the angles precise and even. It's bloody brilliant in my view. It's a bit like cheating but my customers love it. I've measured before and after on the BESS sharpness scale and can get knives 2-5 times sharper than factory.
Looking real sharp! Glad you were able to take the damage out, without taking it to the belt grinder. Those harder knives usually have been tempered at around a very low 150 degrees Celsius. This means exposing the blade to everything above that, will ruin the heat treat. Because Japanese chef knives are ground so thin(and therefore heat up very quickly at the apex), it is very easy to only realize too late, that damage has been done (even with frequent dunking in water).
@@tau4320 yeah, they're pretty cool. I love filming them whenever they come up on my bench because I know you guys like them. They're pieces of useful art.
Hi Marty! Greetings from the colonies. Sure is. It's called edge leading and it's superior than edge trailing where the wheel turns away from the knife.
0:58 - I dont know if it applies to these ones, but several of mine was like this in the start and some even come with a note in the box saying that due to decarb it will take 2-3 regular sharpenings before they get the properties they are supposed to have. This is one smexy knife though, I want one
@@iSharpen Honbazuke? Yeah we talked about that a while ago, but thats done on purpose and requires you to do some reprofiling and all that, the decarbonization I mean here is just a byproduct of the heat treatment drawing the carbon out in the thinnest parts and you need to get down to the "fresh" metal below it. Its really common tbh, the last spyderco knife I bought in Cruwear was like this too, I hated it so much in the beginning because it wouldnt take a screaming sharp edge and certainly would not stay sharp for long. Now though, its like a completely new knife. Personally I think this is a bit shady, because while I understand that it happens, I think they should grind that out themselves in the factory so A: we actually get the correct impression of the knife right away, B: Its actually finished, and C: because if you dont like it after sharpening/reprofiling it, its kinda rough sending it back sometimes. Some companies are cool with it but others seem to consider it going to mcdonalds and complaining about your burger after its eaten
@@kvernesdotten 100% agree, that's shady AF. How many people even know a sharpener like us let alone know how to do it themselves. Seems selfish and self aggrandising to me. So what, if you don't have all the correct tools and skills you're not fit to own a high class knife? That sucks. Do you think that's what's going on with this knife? He says it was never very sharp even when brand new. He's used it for only a very short time then brought it in to me.
@@iSharpen Iiii dont know to be honest, I dont know what this knife in particular is, I see someone saying its a Yoshikane and those are pretty expensive. My experience has been that people who buy that expensive knives tend to look after them, but whether or not its decarb, user error or simply a bad steel/heat treat I guess we cant really know unless he comes back and tells you it completely changed its cutting performance and edge retention. The exact metallurgy of this is not my specialty, but according to Larrin Thomas' website and book the decarbed layer should typically be somewhere between a few micron to 0.2 mm thick, and if its really bad it should be visible as noticeably lighter colored metal. So if this was the issue with this knife it seems likely you already ground past it, right? Lets hope your guy comes back for another sharpening at some point and says something about it!
@@NonScientificBladeTesting cool. It's reliable but make sure you use Tally-Ho or Rizka green as they're both 17gsm. I think Rizka red are 17.5gsm but I don't think half a gram over a square meter will make much of a difference. The main purpose of the test is if it catches, sone burr remains. Or some root if the burr (wire edge) remains which fold over the apex as soon as it's used causing premature bluntness. Or so the story goes. If it can slice cleanly through rolling papers it's also the equivalent to about 100 BESS in my experience cross testing. Please let me know how you go. There's a white paper on it floating around somewhere. I'll see if I can find the link.
@@iSharpen thanks for the great advice! I tried a similar yet different test: I use tailors paper which is also VERY thin and I wrinkle it and cut it if you are interested you can find a short on my channel :) also very difficult to cut
Somthing fishy about that bunka burr after 1 pass , I have a bunka and a Tormek it took me several passes to get a burr,course the metal is so Hard, but still you did a good job as always stay safe m8
That's a Yoshikane likely in SKD. Super thin edges. Typically hardened to 63-64 HRC so making the angle steeper than normal is a good idea to maintain the performance. I have the 270mm gyuto version and it is beast of a laser.
Thanks for your comment. I can't read Japanese so have no idea what it is or what it's made of. With these I like to take the lightest touch possible and use a low angle to maintain it's ability to be very sharp. Customer was happy and says it's now a lot sharper than when new.
Baz, always a pleasure to watch you working with your good old T8.
By the way, I am also a big fan of beginning with the tip and end towards the handle to achieve a very regular bevel.
I am still wondering why you do not do a "guided" de-burring using a support bar. I always fear to round of the apex to much when de-buring free-hand.
Of course I can perfectly see, that you have very controlled hand movement as a former welder :-))
On my T8 I am using the extended universal support US 430 to grind and the original shorter support in combination with the MB-102 Multi Base.
Using that one helps, because the black fixation screw of the knife jig does not bump into the „leg“ of the support rail.
Other than that for some 3-layer Japanese knives (HRC 63) , I felt to give the SJ 250 another try, and guess what: doing extremely light alternating passes towards the end of the grind and then guided honing revealed a stellar result. No bess test results I can share, but paper tests all passed nicely and extremely smooth….
Maybe the SJ 250 is only good for high hardness steels???
Greetings again from very rainy Zurich, Felix
I just subscribed mate....like you presentation style
Thanks Wade! I look forward to reading and responding to your comments.
Do you think it's possible there's a problem with your angle finding process?
The bevels seem to always be much larger than I would expect.
Such an interesting system. I only use Japanese wetstones to sharpen all my knives, super interesting how you can change the grit with different plates, I'm slightly confused tho because I use diamond plates on my stones to flatten them every time, but my stones don't change grits like this system does. Very cool, cheers.
The Tormek system is based on the traditional fixed stone system but instead the wheel rotates in a water trough for an added industrialised aspect and has a guided rail system to keep the angles precise and even. It's bloody brilliant in my view.
It's a bit like cheating but my customers love it. I've measured before and after on the BESS sharpness scale and can get knives 2-5 times sharper than factory.
@iSharpen super cool!!
Looking real sharp! Glad you were able to take the damage out, without taking it to the belt grinder. Those harder knives usually have been tempered at around a very low 150 degrees Celsius. This means exposing the blade to everything above that, will ruin the heat treat.
Because Japanese chef knives are ground so thin(and therefore heat up very quickly at the apex), it is very easy to only realize too late, that damage has been done (even with frequent dunking in water).
I always love seeing Japanese knives on the channel as someone who them.
@@tau4320 yeah, they're pretty cool. I love filming them whenever they come up on my bench because I know you guys like them. They're pieces of useful art.
Hi there from the uk I have a tormek 2000 which the wheel grinds twd the knife is your setup the same way ..cheers
Hi Marty! Greetings from the colonies. Sure is. It's called edge leading and it's superior than edge trailing where the wheel turns away from the knife.
Another knife is love to own. Beautiful
0:58 - I dont know if it applies to these ones, but several of mine was like this in the start and some even come with a note in the box saying that due to decarb it will take 2-3 regular sharpenings before they get the properties they are supposed to have.
This is one smexy knife though, I want one
Actually, now that you say that. I think the Japanese have a word for it.
@@iSharpen Honbazuke? Yeah we talked about that a while ago, but thats done on purpose and requires you to do some reprofiling and all that, the decarbonization I mean here is just a byproduct of the heat treatment drawing the carbon out in the thinnest parts and you need to get down to the "fresh" metal below it. Its really common tbh, the last spyderco knife I bought in Cruwear was like this too, I hated it so much in the beginning because it wouldnt take a screaming sharp edge and certainly would not stay sharp for long. Now though, its like a completely new knife.
Personally I think this is a bit shady, because while I understand that it happens, I think they should grind that out themselves in the factory so A: we actually get the correct impression of the knife right away, B: Its actually finished, and C: because if you dont like it after sharpening/reprofiling it, its kinda rough sending it back sometimes. Some companies are cool with it but others seem to consider it going to mcdonalds and complaining about your burger after its eaten
@@kvernesdotten 100% agree, that's shady AF. How many people even know a sharpener like us let alone know how to do it themselves. Seems selfish and self aggrandising to me. So what, if you don't have all the correct tools and skills you're not fit to own a high class knife? That sucks. Do you think that's what's going on with this knife? He says it was never very sharp even when brand new. He's used it for only a very short time then brought it in to me.
@@iSharpen Iiii dont know to be honest, I dont know what this knife in particular is, I see someone saying its a Yoshikane and those are pretty expensive. My experience has been that people who buy that expensive knives tend to look after them, but whether or not its decarb, user error or simply a bad steel/heat treat I guess we cant really know unless he comes back and tells you it completely changed its cutting performance and edge retention.
The exact metallurgy of this is not my specialty, but according to Larrin Thomas' website and book the decarbed layer should typically be somewhere between a few micron to 0.2 mm thick, and if its really bad it should be visible as noticeably lighter colored metal. So if this was the issue with this knife it seems likely you already ground past it, right?
Lets hope your guy comes back for another sharpening at some point and says something about it!
Great job my friend! Gonna try that cigarette paper test when i am back from my holidays!
@@NonScientificBladeTesting cool. It's reliable but make sure you use Tally-Ho or Rizka green as they're both 17gsm. I think Rizka red are 17.5gsm but I don't think half a gram over a square meter will make much of a difference. The main purpose of the test is if it catches, sone burr remains. Or some root if the burr (wire edge) remains which fold over the apex as soon as it's used causing premature bluntness. Or so the story goes. If it can slice cleanly through rolling papers it's also the equivalent to about 100 BESS in my experience cross testing.
Please let me know how you go. There's a white paper on it floating around somewhere. I'll see if I can find the link.
@@iSharpen thanks for the great advice! I tried a similar yet different test: I use tailors paper which is also VERY thin and I wrinkle it and cut it if you are interested you can find a short on my channel :) also very difficult to cut
@@NonScientificBladeTesting I'll check it out.
You are very smooth Sir!😊
Somthing fishy about that bunka burr after 1 pass , I have a bunka and a Tormek it took me several passes to get a burr,course the metal is so Hard, but still you did a good job as always stay safe m8
It's very thin, and has a good edge. It didn't need much to give it a sharp apex.