Restoring a Kasumi Finish?

[krx927]

I use a piece of wooden stick on which I glued some felt. I cut the sand paper the same width as the felt and wrap it around. It works perfect - you can see it in the picture.

But nice tip for using old magnet rack for holding the knife. I was clamping it in (on the pic is western Akifusa). This works perfect for western handles and octagonal handles, but with D shaped it is a big problem -> you can not fix it good.

 

[Asteger]

I use a piece of wooden stick on which I glued some felt. I cut the sand paper the same width as the felt and wrap it around. It works perfect - you can see it in the picture.

But nice tip for using old magnet rack for holding the knife. I was clamping it in (on the pic is western Akifusa). This works perfect for western handles and octagonal handles, but with D shaped it is a big problem -> you can not fix it good.

Looks good :thumbsup:

 

[Dave Martell]

You guys with natural stones, don't forget to use your cork 'n mud for the final finish on kasumi bevels.

 

[mikedtran]

Just got a gifted uchi finger stone (from DDPslice) in and its HUGE! Really appreciate the amazing generosity =)

The stone measures 42mmx32mmx8mm.

 

[mikedtran]

Question about using Fingerstones: instead of glueing and creating a backing, can you instead create mud and use a cotton swab to apply it to the blade (will that have a similar effect)?

 

[Smurfmacaw]

Question about using Fingerstones: instead of glueing and creating a backing, can you instead create mud and use a cotton swab to apply it to the blade (will that have a similar effect)?

Cotton swab?? I guess it would.....after about 40 hours lol. I think Maksim uses a nagura and then collects the mud and uses a cotton cloth to finish his for go even out any blotches. I've been pretty lucky and my finishes have come out pretty even if I use thin stones.

 

[mikedtran]

Haha I meant cotton balls* cotton swab would take forever!

 

[Smurfmacaw]

Here's what the stone looks like when thinned to working thickness. You should get something similar on Monday. No inclusion though, I sent you a clean piece. A piece this size should make between 9 and 12 fingerstones and each one will do two 180mm gyutos and still maybe have some thickness left if you had a really good finish prior to using a finger stone.

 

[mikedtran]

Awesome! Thanks smurf!

Has anyone used polishing stones from congresstools? I read on another knife forum that they can be used instead of sandpaper. Should arrive next week, will probably get around to using them in January after vacation and will report back =)

 

[ynot1985]

on the topic of finger stones... is there any where I can read up what is happening? I have seen maxim's 3 youtube clips but I don't understand what he is doing to prepare the finger stones...there's no instructions in the clips. I'm tempted to buy come finger stone but I want to know how to prepare it before I do so? can any tell me or direct me to a page that may explain the process?

 

[mikedtran]

on the topic of finger stones... is there any where I can read up what is happening? I have seen maxim's 3 youtube clips but I don't understand what he is doing to prepare the finger stones...there's no instructions in the clips. I'm tempted to buy come finger stone but I want to know how to prepare it before I do so? can any tell me or direct me to a page that may explain the process?

Maksim has this blog post that has a tiny bit more info.

http://www.japanesenaturalstones.com/finger-stones-how-to/


From what I gathered from this and from other forum members:
-Thin stones to about 1mm
-Glue tissue paper
-Thin stones to about 0.5mm
-Score the thin stone in a 1mmx1mm grid, and split on back of a spoon (this gives you a flexible web of stones)

 

[aboynamedsuita]

I'll probably end up starting a thread in sharpening station, but does anyone familiar with J-Nats know the pros/cons of using kiita vs uchigomori for finger stones? I got one of each from Maksim recently.

 

[Smurfmacaw]

on the topic of finger stones... is there any where I can read up what is happening? I have seen maxim's 3 youtube clips but I don't understand what he is doing to prepare the finger stones...there's no instructions in the clips. I'm tempted to buy come finger stone but I want to know how to prepare it before I do so? can any tell me or direct me to a page that may explain the process?

I did a very basic tutorial here http://www.kitchenknifeforums.com/s...-Finger-Stones?p=375760&viewfull=1#post375760

If i have the time this weekend I'll do a detailed thread on how exactly to prepare the stones. It's pretty easy, not nearly as hard as it seems. A set of inexpensive calipers from Harbor Freight helps a lot but you can just eyeball it, I'm sure that's how they did it in the 14th century. With no real effort I can keep the thickness of the stone to within .02mm. I'm sure I could build a jig to keep it even closer but I don't see any reason it needs to be that precise. The thinned, fractured stones do give much better results than a larger solid piece. I wish I had taken some pics of when I did the Carter.....it illustrated the benefits. If anyone has a Carter that want's a Kasumi finish, polish it to a mirror and send it to me, I'll put the fingerstone to it for free. I just sent my (wife's) Carter off for a cool rehandle so I won't see it for a couple of weeks.

 

[aboynamedsuita]

Does the Kasumi go well on a stainless clad HG carter or does it need to be carbon clad?

 

[Smurfmacaw]

Does the Kasumi go well on a stainless clad HG carter or does it need to be carbon clad?

Actually it looks pretty good. There's no clouds but it looks WAY better than Murray's 40 grit finish. I'm just not a fan of the big scratch finish.

 

[aboynamedsuita]

Actually it looks pretty good. There's no clouds but it looks WAY better than Murray's 40 grit finish. I'm just not a fan of the big scratch finish.

Cool, I should give it a shot with the ones I got from Maksim. Agree about that finish too, probably going to be a PITA to get them out, I'm polishing my ZK 52100 10" atm and that's a lot of work. Even after starting 180,400,600,15M,3M,0.5M I'm still not happy, must be because it's mono-steel, SS cladding is likely softer. Maybe I should get a felt wheel and use the Cr2O3 compound

 

[daveb]

P Tiger did a real nice job of this with a King 800. It's documented in a thread here somewhere.

Jon's Gesshin Aoto is designed with this work in mind. His site has a video of the stone in use.


I've tried and liked both but it's a lot like work. I find I'm less upset with scratches now...

 

[ynot1985]

Thanks Mikedtran and Smurfmacaw.. time to do some reading

 

[mikedtran]

Finally back from vacation and spent about 1 hour polishing the blade up to 2k and then took it to the finger stones. I used a pre-thinned stone from smurfmacaw and I think I'm doing something wrong because it is leaving a lot of scratches.

Am I just not taking enough time on it?
Should I be more gentle?

 

[buttermilk]

What is your process on the way to finger stones? If your goal is to rid the blade of all stray scratches, you need to either go to a progressively coarser grit until no irregular scratches are seen, or be prepared to spend a significant amount of additional time at finer grits. Essentially, you don't want to move on to a finer grit until there are no remaining scratches visible from the previous grit. A technique that is worth mentioning, but one that I don't at all recommend for these purposes, is perpendicularly shifting the direction of scratch pattern as you move towards finer abrasives. In this case, you wouldn't have wanted to move past your starting grit until all the irregular and pre-existing scratches were removed.

 

[mikedtran]

Hey Sam!

I've been doing just heel to tip strokes going from 200->2000. I've been checking with a 30x loupe before for the scratches and it look very clean (I do about 15-30 passes on each grit). At 2000 even in bright florescent lightning I'm not catching any stray scratch marks.

My issue is the finger stones are scratching the blade and I'm wondering if I'm doing something wrong with the finger stones? Should the finger stones be scratching the blade at all?

*Picture of 1500 with some finger/oil smudges.

 

[JBroida]

depending on what finger stones you are using and how you are using them, the answer is yes, they are likely to scratch the blade a little bit.

 

[Asteger]

So, those swirly, loopy or wavy stratches where not there before you moved to the fingerstone? Can't tell from the photo above.

I'd guess 2 things maybe. It's quite hard to polish really uniformly from heel to tip and not make errant waves or whirls or something. I'll struggle with this and try to use something to guide my hand somewhat, while the pros seem to have gizmos that help in this regard. (Would like to learn more about these.) But if those sratches are newly formed from the fingerstone, then looks like the stone has some impurity or rough edge to sort out as the scratches which jump are from more specific places, suggesting it's not the whole fingerstone. Also check if there are rough bits on the edge.

Incidentally, about uniform finish patterns - everyone likes a Shigefusa and the polish patterns they get are very much parallel, with the aid of an aforementioned gizmo (a kind of rack thing). I was happy to get a Shigehiro (ie. not Shigefusa) yesterday with quite a nice finish, I think, and I like it because it seems a bit more 'human' or achievable to me, and so something that's more possible to maintain in time. The polish is very nice but not completely of uniform heel-to-tip perfect Shigefusa-style lines. It looks more handmade in a good way and doesn't make me feel inadequate like a Shigefusa would. The lines nearest the spine are parallel to that, with most more parallel to the edge, and they come together towards the tip. (I imagine he gets the pattern near the spine first, and then near the edge.) Took a photo before first use and maybe you can see what I'm thinking of:

 

[mikedtran]

So, those swirly, loopy or wavy stratches where not there before you moved to the fingerstone? Can't tell from the photo above.

I'd guess 2 things maybe. It's quite hard to polish really uniformly from heel to tip and not make errant waves or whirls or something. I'll struggle with this and try to use something to guide my hand somewhat, while the pros seem to have gizmos that help in this regard. (Would like to learn more about these.) But if those sratches are newly formed from the fingerstone, then looks like the stone has some impurity or rough edge to sort out as the scratches which jump are from more specific places, suggesting it's not the whole fingerstone. Also check if there are rough bits on the edge.

I made a little "gizmo" which is really just a knife hard piece of felt that I wrap the sand paper around to get really straight lines.

No swirls in the blade before the finger stone. I can actually actively see the fingerstone scratching the blade as I polish. It seems to primarily happen in the first couple passes so I might just need to run the fingerstone on a high grit stone 6000+ for more strokes before hitting the blade?

This is my blade at 320 grit (Might be blasphemy, but I kind of like the satin finish around 600-800):

 

[Smurfmacaw]

I've found that the less pressure you use the better. It seems to work best (for me anyway) to get a good base of mud and just glide the fingerstone around kind of floating it in the mud. Maksim pretty much said it with the "not too wet and not too dry" mantra. If it feels gritty stop, wash the fingerstone and maybe hit it on a very fine stone to make sure there are no "chunks". I do wonder if using a synthetic stone could be detrimental since the abrasive is apparently more three dimensional as compared to the "flakes" of a natural stone.

Also, I found that if you make any sort of circular motion in you polishing it'll give you swirlies. I go back and forth in about 1 inch strokes moving up only a microscopic amount to do the vertical section of the blade starting at the top, working to the bottom and then back to the top. Then I just extend the next stroke on the top about 3/4 of an inch and repeat until I've done the whole blade and back. Every pass is lighter and lighter until it's literally just floating the stone in the mud. A thick but not dry consistency is best. It will turn black so you know it's cutting metal. Finally I use long, no pressure strokes the length of the blade ensuring there is no vertical movements.

I'll try to post a close up of the Carter I did. It came out pretty decent.

What I'm wondering is if the puffballs in sword maintenance kits that supposedly contain Uchimagori powder might be a good source of powdered natural stone for the final evening out of the finish....I just need to find someone I can trust that sells them (I think some are just filled with talcum powder rather than powdered Uchi.)

Bottom line though it looks like you are making U-turns with the stones rather strictly back and forth to get those particular scratches. How Shig does it to get the misty look and a nearly mirror finish if still kind of a mystery....but then I haven't been doing it professionally for 50+ years either.

 

[mikedtran]

I've found that the less pressure you use the better. It seems to work best (for me anyway) to get a good base of mud and just glide the fingerstone around kind of floating it in the mud. Maksim pretty much said it with the "not too wet and not too dry" mantra. If it feels gritty stop, wash the fingerstone and maybe hit it on a very fine stone to make sure there are no "chunks". I do wonder if using a synthetic stone could be detrimental since the abrasive is apparently more three dimensional as compared to the "flakes" of a natural stone.

Also, I found that if you make any sort of circular motion in you polishing it'll give you swirlies. I go back and forth in about 1 inch strokes moving up only a microscopic amount to do the vertical section of the blade starting at the top, working to the bottom and then back to the top. Then I just extend the next stroke on the top about 3/4 of an inch and repeat until I've done the whole blade and back. Every pass is lighter and lighter until it's literally just floating the stone in the mud. A thick but not dry consistency is best. It will turn black so you know it's cutting metal. Finally I use long, no pressure strokes the length of the blade ensuring there is no vertical movements.

I'll try to post a close up of the Carter I did. It came out pretty decent.

You are spot on in that I'm 100% making u-turns and swirling the stone as I didn't originally think that it would scratch the blade...and it definitely did =p

What I'm wondering is if the puffballs in sword maintenance kits that supposedly contain Uchimagori powder might be a good source of powdered natural stone for the final evening out of the finish....I just need to find someone I can trust that sells them (I think some are just filled with talcum powder rather than powdered Uchi.)

Bottom line though it looks like you are making U-turns with the stones rather strictly back and forth to get those particular scratches. How Shig does it to get the misty look and a nearly mirror finish if still kind of a mystery....but then I haven't been doing it professionally for 50+ years either.

Great tip! I think I was really rushing it and applying too much pressure.

You are spot on in that I was swirling and making u-turns as I didn't think the stone would scratch the blade...which it definitely did =p

Also during the scoring and flexible of the stone I found I lose some bits? Does this happen to you? Probably again not being gentle enough in flexing it over the spoon.

Thanks again for all the tips and generosity =)

 

[Smurfmacaw]

Great tip! I think I was really rushing it and applying too much pressure.

You are spot on in that I was swirling and making u-turns as I didn't think the stone would scratch the blade...which it definitely did =p

Also during the scoring and flexible of the stone I found I lose some bits? Does this happen to you? Probably again not being gentle enough in flexing it over the spoon.

Thanks again for all the tips and generosity =)

Just push once on the spoon. That will make it flexible enough. I'm looking at trying a new adhesive though as the epoxy doesn't stick as well as I'd like but that could be a product of it being a soft "flaky" stone in the first place. Also, last two stones I made I had an issue with the epoxy setting way harder than it had previously. I'm going to look at a different cement once I get some time to see if I can get stones where you don't have to be really delicate with. Maybe Jon can weigh in on better adhesives (that are obtainable outside of the sword polishing community in Japan.)

 

[Asteger]

You are spot on in that I was swirling and making u-turns as I didn't think the stone would scratch the blade...which it definitely did =p

Also during the scoring and flexible of the stone I found I lose some bits? Does this happen to you? Probably again not being gentle enough in flexing it over the spoon.

Even if they don't 'scratch' you can't swirl around as though you're using a washing sponge Follow the polish pattern you want. Definitely, I'll get some loose bits too and when you've thinned down the stone it's pretty fragile and stuff breaks off, though if the stone's of regular quality there shouldn't be any deep scratches

 

[Smurfmacaw]

Here's a quickie refinish I did on one of my Shigs....this knife has been through hell, inexpert sharpenings, scotchbrite pads, barkeeps friend, broken tip, thinned etc. Light pressure, plenty of mud and patience. I think it would have come out better if I had taken it to a full mirror polish prior to the fingerstones but this came out more than acceptable. (Ignore the schmutz on the higane....it was early in the morning and I missed some lint.)

 

[MAS4T0]

Here's a quickie refinish I did on one of my Shigs....this knife has been through hell, inexpert sharpenings, scotchbrite pads, barkeeps friend, broken tip, thinned etc. Light pressure, plenty of mud and patience. I think it would have come out better if I had taken it to a full mirror polish prior to the fingerstones but this came out more than acceptable. (Ignore the schmutz on the higane....it was early in the morning and I missed some lint.)

Wow! That looks great.

How long did it take and what grit/ stone progression did you use?