Advice to recreate rough finish of Sakai knives.

[dAtron]

Hello all.

To give a bit of context I recently thinned and gave a Hamaguri grind on my Migoto blue 1 and realised that the shoulders were not as rounded as it came out the box and started wedging more than I like. I decided to round off the shoulders a little bit to make them less prominent. In the process though the finish above the shinogi has been scuffed as you would expect.

I want to restore a similar matt/rough looking finish that comes with Sakai knives. My plan is to tape the bevel below the shinogi line and use powder to restore the finish above the shinogi.

From my understanding most sharpeners use powders to apply such a finish but would like to know what a good starting point is to acquire or make my own rough powder. I have Uchigomori powder but that is too fine to get rid of the scuff marks and recreate what I am looking for. I also have access to all grades of silicone carbide powder through various vendors on ebay.

So my question is anyone have any experience on how to best recreate that finish?
Is this the right way to go about it?
What kinds of powder grits would I have to mix up?

This is the original rough finish that I want to restore.

 

[esoo]

You can make a coarse powder with a diamond plate + cheap stone of your choice. I've used a King K-80 (250/1000) stone and ground it down (with the stone dry) with a cheap diamond plate.

What I'd done in the past here: the grandiose synth kasumi thread

But you should be aware, that I'm under the impression that the stock finish on many j-knives is done via media blasting, not stones or powder. Using stones would increase the price (due to the time involved)

 

[dAtron]

You can make a coarse powder with a diamond plate + cheap stone of your choice. I've used a King K-80 (250/1000) stone and ground it down (with the stone dry) with a cheap diamond plate.

What I'd done in the past here: the grandiose synth kasumi thread

But you should be aware, that I'm under the impression that the stock finish on many j-knives is done via media blasting, not stones or powder. Using stones would increase the price (due to the time involved)

Interesting. I have an old wafer of Cerax 320 that has been sitting there unused, might grind it into powder and use that. Did you combine both 250/1000 powders or just used one of the two?

 

[Bico Doce]

I would use some sand paper to get rid of the scuff marks first and then use the stone powder to finish it off. If you just use the powder the scuff marks will likely still be visible when you're done

 

[esoo]

Interesting. I have an old wafer of Cerax 320 that has been sitting there unused, might grind it into powder and use that. Did you combine both 250/1000 powders or just used one of the two?

I used the powders separately - either 250 or 1000. When you grind the powder, do it onto parchment paper to control the mess (as it is quite fine).

I was trying to follow this, but couldn't find stone powder so just ground my own.

 

[JBroida]

you guys crack me up... no one is sitting in sakai doing the same kinds of finishing methods you all talk about here. Things are bead blasted, wood wheels with abrasive are used, buffers are used, etc... but no one is sitting there with sandpaper and natural stone muds finishing the sides of knives. For wide and single bevels, you'll see abrasive applied in a very specific way, followed by a very brief rub with that workshops special kasumi mud (which is far coarser than people here realize). The kinds of things talked about here are purely the product of hobby-oriented individuals and adaptations of sword polishing techniques, not commonly found in the knife world.

 

[dAtron]

you guys crack me up... no one is sitting in sakai doing the same kinds of finishing methods you all talk about here. Things are bead blasted, wood wheels with abrasive are used, buffers are used, etc... but no one is sitting there with sandpaper and natural stone muds finishing the sides of knives. For wide and single bevels, you'll see abrasive applied in a very specific way, followed by a very brief rub with that workshops special kasumi mud (which is far coarser than people here realize). The kinds of things talked about here are purely the product of hobby-oriented individuals and adaptations of sword polishing techniques, not commonly found in the knife world.

Thank you for your insight Jon. It sounds like it will be hard to recreate such a finish at home. I will probably try very coarse silicone carbide powder and try and work around that. If you have any other tips on how to restore the look please let us know.

 

[Bico Doce]

no one is sitting in sakai doing the same kinds of finishing methods you all talk about here.

Well I feel cheated

 

[JBroida]

without similar equipment and materials, its not easy... but I think simple sandpaper finishes work quite well and are easy for end users to maintain... and shouldn't that be an important thing to consider too?

 

[Bico Doce]

I will probably try very coarse silicone carbide powder and try and work around that.

Even though there isnt someone is Sakai using varying grits of sandpaper to create that finish, the tools they are using are intended to create the same effect - a consistent scratch pattern. An inconsistent scratch pattern will show throw the finish the powder will create but that could be a none issue for you. I personally dont mind a few errant scratches

 

[JBroida]

yup.... consistent and even finishes with good surface prep... that's the name of the game. Many ways to do it... you certainly don't have to follow the "traditional" methods. My comment was just a function of how often I hear from people about doing work like this, thinking they are doing the same kinds of things the craftsmen are doing- trying to accurately recreate, both in method and finish, what the original knifemakers have done with their knives. I say just employ common sense and try to create a finish that looks good and is easy to maintain, as those things matter more in the long run. Sticking to what something was like when it was brand new is antithetical to the ethos of things like these being functional tools. The idea, even when you speak to the knifemakers about this, is that you develop a relationship with your knife, figure out how you want it to work, and employ common sense to achieve that and squeeze all the performance you can get out of it. The more you work with it, the better you understand it, and the better job you can do and getting it to work the way you want.

 

[dAtron]

yup.... consistent and even finishes with good surface prep... that's the name of the game. Many ways to do it... you certainly don't have to follow the "traditional" methods. My comment was just a function of how often I hear from people about doing work like this, thinking they are doing the same kinds of things the craftsmen are doing- trying to accurately recreate, both in method and finish, what the original knifemakers have done with their knives. I say just employ common sense and try to create a finish that looks good and is easy to maintain, as those things matter more in the long run. Sticking to what something was like when it was brand new is antithetical to the ethos of things like these being functional tools. The idea, even when you speak to the knifemakers about this, is that you develop a relationship with your knife, figure out how you want it to work, and employ common sense to achieve that and squeeze all the performance you can get out of it. The more you work with it, the better you understand it, and the better job you can do and getting it to work the way you want.

Absolutely agree with you here. I usually don't care about altering the finish. And not to bothered about scuff marks. I see knives as tools to be modified to fit me best. In this instance I just wanted this to be a small project over the weekends to see if I could get close to that finish. Alas I will head your advice and keep my life easy. I'll just sandpaper it and use some powder. Thank you.

 

[HumbleHomeCook]

Absolutely agree with you here. I usually don't care about altering the finish. And not to bothered about scuff marks. I see knives as tools to be modified to fit me best. In this instance I just wanted this to be a small project over the weekends to see if I could get close to that finish. Alas I will head your advice and keep my life easy. I'll just sandpaper it and use some powder. Thank you.

Be sure to report back with your results!