Masamoto deba restoration (WIP)

Hello,

This project was finished even before a project from my previous post, but I thought that it will be better to post it in that order. When I was in my lazy stagnancy, a good friend of mine Michal, who is writing ‘’My sushi adventures’’ blog on Facebook, wanted to encourage me to do something and he sent me his two knives for some spa. We have agreed that it will be up to me what will I do with his knives and if I won't find the strength and energy then I can send them back. That was quite fair. The knives are Masamoto Deba bought on Tsukiji market in Tokyo and Toyama Usuba which I brought for him last year while being in JNS on annual gathering . I totally love these knives. The Masamoto deba is different than other blades from the same manufacturer I have seen before. It’s plain on the bevel side and it has a kanji on the back side. Toyama Usuba is another example of a great workmanship. Fit and finish of new knives from Toyama is excellent. I have started from making sayas for both knives and then followed with some spa. In this post I will focus only on restoration of Masamoto Deba, however I would like to mention that Toyama blade differ from Masamoto a lot in regards of hardness and the way it was polishing. It was simply harder.



The overall condition of this knife was good. Any rust that appeared on the blade was my fault, because when I was making sheath for that knife I left it laying in my kitchen and I kept picking it up with wet hands. Also there is some glue residue on the back side as well as on the very edge of the blade. This is because I was trying the fit of the saya straight after gluing wood together.

















Flat part of ''kataba'' (single bevel knife) is never flat. It's concave in most of the knives of this type, because they are ground on the huge grinding wheels.









Back side









I really like kanji on the back side instead of the bevel side.

















First thing first, I have decided to flatten the ''flat'' side of the blade on the JNS300 stone. Usually you want the roughest stone you own to do that.









Can you see the outline below? This is indication that this part of the knife is not flat. I will be sure that it is even when this lines will meet.



















It didn't take me a long time to flatten this part. Picture below represents a flatten knife straight out of JNS300. From now on it should be quick to re-polish that part of the blade.













JNS 800











And this is the polish from synthetic Red Aoto. I was grinding the knife perpendicularly to the stone, but to finish it off I was doing collateral moves, so you can see straight scratch lines that are going alongside the blade.













As a next step I have planed to re-polish ura side. I have quickly do some uraoshi sharpening to see where the edges are and to reassure that back of the blade is flat.













Once it was done, I could start polishing that part of the blade. I have started from chipping small piece of ura fixers. This is a rough stone. I even didn't care to prepare it properly, in the way you usually prepare finger stones. I just wanted to remove original grinding scratches.













Here is the finish from that stone. It already look better and it is just beginning.









I think that I am getting addicted to destroying my stones. On the picture below you can see JNS800 which I accidentally broke some time ago, glued it back and broke it in to 4 pieces a moment after I took that picture. No worries, I have already glued it back.







JNS 800 finish











Natural Red Aoto finger-stone...









... followed by wine cork with Aoto mud.

















Takashima fingerstone:



















I have used Uchigumori finger-stones to finish polishing. To be honest with you I could stay with the finish I already had. For some reason my Uchigumori were scratching back of the blade (as well as front, but I will explain that later on) or the scratches were hidden between other scratches and waiting for finer stones to show up. That is as erious lesson which everybody should remember. You can't progress with grits or stones until you are 100% sure that all scratches from previous grits are gone. If you spent 2 hours on one grit and you have one super tiny, microscopical scratch which you can't remove, then you won't be able to remove it later. Don't lie yourself and don't waste your time with next grit. Trust me I know. I have been there and done that. Sometimes, when all that you can see are the scratches going into the same direction, you are not able to see scratches from the other grits. This is why sometimes it is a good practice to change direction of the scratches. While doing that you will be able to recognize other scratches, which you didn't remove before.

























When I finished polishing the back and front of the blade I have started working on the bevel. Below is the end result. Again... I was too fast and I went with progression to fast without removing properly the old scratches. And later, when I finished on my Red Oohira you could see them. They were quite ostentatious.























I thought that I will use something special for a final touch. Now I know that it was a stupid idea, because to use special things for that purpose you must be sure that everything is perfect.



I took some Uchigumori chips and powder from the box with fingerstones and ground it to fine powder in the mortar. I have done the same thing with White Binsui.



Uchigumori powder:





White Binsui powder:











And guess what?? That was a mistake. There were bigger particles in the powder which scratched the surface of the blade. I was really upset. I should have taken more care while grinding that powder, because I believe that a good mixture of natural stone powder (or even synthetic one) with water or oil can give you exceptional results.









After everything what happened before, I have quickly repeated everything, but have finished on Red Aoto. Here is effect and I hope that you like it.

 

wonderful work. very artfully presented. great photography

 

Super nice! Well done!

 

damn
nice work.
How many hours would you say this took?

 

Outstanding work! Thank you for posting it.

 

that's some amazing work

 

Thanks guys. Antonio I don't know. I don't have much time, so I do it when I can bit by bit. However it didn't take that long.

 

Fantastic work!!!

 

Impressive stuff! Well done!

Lars

 

@BathonUk how did you work the powder over? cork? And assume you tried to get it as fine as possible in mortar?

 

Super clean work!!!

 

I've done it in the mortar, but it seems that I didn't do a good job with uchigumori. Next time i will try it in the electric coffee grinder

 

This was a wonderful write up and the photographs are exceptional. Articles like these go a long way in clearing things for us newbies, so thank you.

 

well done! beautiful!