burkecutlery wrote:So I have a question on the topic of Moritakas, as they are the issue of the day.
When they come new, they have a hazy, kasumi-like finish on the secondary bevel. When you sharpen them and they have dips and divots like you said they should, and you should not sharpen them out, what is the suggested course of action to maintain that knife when sharpening? It will no longer look even and hazy, unless you hit it with a fingerstone. Even on a muddy jnat, it won't get up into all the high spots without applying direct pressure, and thereby creating a hole in the edge(even if there wasn't one).
Also, most Japanese hand-made knives sold slightly over-thinned and over-sized so you can set the edge how YOU like it, kind of assuming that you will open the knife with a stone ready to go.
So, are these knives intended to have a scattered, disconnected finish? If so, why do they come looking matte and hazy? Is it suggested that everyone with one should have fingerstones? Something else?
This topic has become quite hot lately and I'll just add my 2 cents here. I've got 2 Moritaka's myself and have sharpened around 12 more I think.
Yes the Moritaka's have very small dimples. I haven't seen one that raised an issue when sharpening them, but it appears some have. I had 1 Moritaka that had a high spot and it came out in 2 sharpening sessions. I use Shaptons mainly, but finish on a Jnat and haven't had any issues myself...
That said, I do understand your frustration when a good looking knife looks worse when you sharpen it. It has happened to me too sometimes and it will aggravate you to no end.
Weather or not it affects the performance is irrelevant. WE sharpen for performance AND cosmetic perfection. Most knife users don't care, but we are not most knife users.
As I said before, I never had the issue, but if it would happen to me, it would drive me nuts as well. I typically use the Moritaka right out of the box and when it dulls, reset the bevel on a 320 Shapton anyway. Maybe that's taking out any "dimples", I don't know.
1. I am not frustrated with them. I have great fingerstones. 2. Kasumi finish is not default from the forge(though wouldn't that be great?) 3. I never implied he is trying to trick anyone.
I'm just saying. It's one thing now, another thing later. Ken was saying the second thing is considered beautiful and more pleasing than perfect. So why is finished at the shop to look like the first thing?
Again, the closest thing I can think of is a knife that, through use, builds a patina. But the patina is built by you, not built by the maker and revealed by you.
I had a Tanaka Yanagiba that came looking nicely hazy and even. I sharpened it like the noob I was and it got wierd looking, and a lot duller. What I didn't know was that the edge was hamaguri and I was applying bogus pressure. After a year, I learned the correct way, and I then discovered there is an overgrind near the heel, up by the shinogi line. It will never make a hole in the edge. It is not intentional. I fixed it with fingerstones. I would recommend that if anyone wants to keep up a low-price-point yanagiba, they get at least one kind of fingerstone, because they are less expensive and will have bumps and dips in the edge that SHOULDN'T affect performance(or else the knife is defective IMO), but look ungainly, and should be hidden.
Is this is the same issue?
I would just stop talking on this, but it seems everyone is completely misapprehending me. I tried to ask a simple question, and everyone's got too much skin in the game to talk about my question.
Nice to hear your customer is happy with the result. Very rewarding indeed! Ken, could you explain me how you deal with an overgrind - both at the heel and let's say in the middle. Or could it be it has been treated in one of your videos? Regards Bernard
I really to enjoy positive feedback from my customers. Honestly it's more valuable to me than the money I get sharpening and why at times I do far more work than I get paid for.
There are various types of overgrinds. In this instance the heel was higher than the area after it by less than 2 mm, so if you laid the knife perpendicular to a flat surface, you could see daylight at the heel. Some people like this and don't use the heel for cutting and think this is a safety feature. I don't and neither did this customer. So there are two approaches to this. You can just grind more just past the heel until it all catches up and becomes flat, keeping the same angle. If it is more severe this will drive you crazy and you just introduce overgrinds and more waviness, so if it is severe, Just grind the whole think flat until you can't pass a sheet of paper between the knife and a granite reference plate (A granite tile will do). Then completely reestablish an edge from scratch. I've had to do this on a number of Takedas - and yes they turned out very well. I like working on Takedas. Before you start hogging metal off one of these styles of knife MAKE sure that they are straight! Again the granite reference is most helpful here too, but knife straightening is yet another topic. Flattening a heel out is very much like removing belly on a knife and the Nubatama Aratae video is good to watch to see this technique demonstrated on a Shun Cleaver,
So there are overgrinds where an area of blade has been thinned too much in one spot or a hollow grind area behind the blade edge of some length and depth. The first question is the intended result - functional or aesthetic, immediate or over time. As sharpeners we remove metal, even as polishers although more slowly. We can't put metal back. So much as the medical field holds to 'First do no harm', I feel this way about knives. If the cure is worse than the disease, don't use it.
If there is a slight hole or concavity behind the edge, take it out. Thinning the blade does this quite nicely with additional benefits. This class of blades responds well to this and often this takes care of it all - as it did in this case. He got a thinned flat edge on both sides. Significantly improved cutting performance and a thinned edge. Final finish was with the Hakka Tomae rather than a more extreme finish so he could enjoy the characteristics of a pure natural stone finish.
At some point the hole or concavity is too great and it is a judgement call as to how thin you should go. You can also just remove metal making the knife narrower until you succeed, much like removing chips. This too has it's limits. Now if the aesthetics are more important than function you make one set of decisions and yes you could use fingerstones or a sequence of fingerstones. I have a pretty good selection and will hhave even more. Or you could purposely make a hollow ground edge. You can also make abrasive paper with natural stones and hand rub the edge, realizing that this further exacerbates the concavity of the surface. There are also a number of other techniques I employ, but the desires of the customer are key in the decision process. You can use things other than natural stone finishes on paper including CBN slurries and hybrid slurries incorporating natural stones and CBN / diamond, depending on the effects you wish to achieve. I also shape fingerstones to match the blade shape to polish out concavities using small pieces of Atomas, etc etc. It becomes an issue of how much art and effort you want to put in to achieving a transient moment of beauty. If I am working on a sickle that at the end of the day will have a dulled chipped out blade no matter how perfect my kasumi finish is, well I don't give a dam about the finish looks, just function - or if necessary I go to great lengths to try to determine the finish of the original knife and duplicate it as best I can, It comes down to judgement and matching my expectations with the customer's requirements. I employ other techniques but this is a good overview.
New to all of this but have 2 moritaka's a supreme petty and a supreme damascus gyuto both are very nice knifes and don't currently exhibit any of the "flaws" being discussed, they perform beautifully and asthetically are to my taste. The damascus finish/grind etc... though is noticeably better than the kurouchi finished knife.
Ken I have a question as I'm still interested in these knifes and all this talk on various boards has me thinking and I wondered if you could clarify, my Damascus Moritaka has very good fit and finish and from all accounts the main issues do not lie with this line. Is this simply due to cost, and are other people involved in the manufacture of these knives? Who in the Moritaka business for example makes what knives and who does the grinding sharpening of for example the standard kurouchi, supreme kurouchi and Damascus lines? I'm beginning to understand what you are trying to say around how Moritaka see their knives i.e. a workhorse that performs at a price, but is the variation in QC of their various models solely down to cost?
Another response from another Moritaka knife sent to me for sharpening along with a couple other knives:
"Hello Ken, I would just like to thank you for Sharpening my knives. I got a chance to use the knives over the past few days and they cut like nothing else. The repairs that were done on the three knifes are great and look like the chips never happened. The finish of the moritaka looks wonderful and is like a working peace of art.
Also, the attention to detail is 5 star and I look forward to working with you in the future.
There ARE Moritaka knife owners out there that are VERY happy with their knives. Letting the few complainers who, pardoning the pun, have their own axe to grind on this topic drown out the happy owners does a disservice to this family of traditional knifemakers whose roots go back 600 years making knives and swords. Think of it - 600 years of customers!
To those haters out there who don't like to sharpen Moritakas, SEND them to me. You know you want to... I love sharpening Moritakas Just don't send them to me after you mess them up and blame the Moritakas for it as has happened in the past Stop whining and start shipping
Here's my take on it. The kuroichi finish is the finish you get from sticking the knife in the furnace. It is a surface oxidation. You see this after it is hammered into shape. . When jewelers make a piece of jewelry out of silver they heat the whole piece red hot. After cooling, it develops a firescale. This is normally polished out. So if a pin back on a piece of jewelry breaks off the ENTIRE piece must be heated up to put a new pinback on. You can do a sparkweld but the connection is not as solid IMO.
So this firescale or kuroichi finish is a natural consequence of the forging process and it has nonstick properties as well. Now if you have a damascus cladding, well you have to grind off the kuroichi finish to reexpose the metal. ANY knife with a kuroichi finish that is naturally produced has a rough surface texture, but it is essentially part of the design. Now if you grind it off it won't be a smooth surface. So you typically refine this surface to a smoother flatter surface. This is quite evident in CCK cleavers. I've removed this firescale finish on one(similar brand to CCK) to see the underlying rough surface. You will also see a 'fake' kuroichi finish on some knives that is far more uniform looking more like a black paint job, something I don't care for at all - and don't necessarily trust what's in the 'paintjob'.
So yes there are extra steps in a damascus clad Moritaka than a kuroichi finish. And again it is personal taste as to what you like best.