# Help me polish a honyaki



## ian (Jul 16, 2020)

Hi all,

I've been working on polishing this Kippington 1095 honyaki. When I got it, the geometry was really quite nice for polishing, with only extremely minimal low spots in places that matter, and a lovely convex all over. So, I only really dropped down to a Chosera 800 for the initial work, going lower than that only on a couple spots on the back that won't matter so much for food release, while keeping them convex. Anyway, since the Chosera, I jumped up briefly to Gessh 2k and 6k just to lighten the scratch pattern a bit, and then spent a bunch of time on this uchimugori I got from @nutmeg. I think it's on the coarser side of uchimugoris, although it's the only one I've tried.

Technique-wise, what I'm doing on the uchi is laying the blade face on the stone with the edge toward me, putting my hands on the blade on either side of the stone with my fingers wrapped over the spine and my thumbs near the edge and directly over the stone, and going back and forth with wobble strokes over the full width of the convex geometry. I've tried with various amounts of water. A medium amount of water seems to work best, whatever that means.

It looks ok now, but not amazing. I'm not going for a true mirror polish (I don't know that that's really possible with this stone.) But I just want something that's even and looks good. Any suggestions on how to improve? Here are some vids I took trying to capture the scratches.





And here's the uchi.







I have some fingerstones too, also from @nutmeg, but they just seem to scratch the blade up when I use them and don't seem to improve the finish. They worked quite well on clad knives though. There's a low spot right underneath the maker's mark that I didn't want to fix, for fear of damaging the feather, so I'll have to figure out some way to get that to look more even too. Was hoping to use the fingerstones, but maybe something else will work.

Help!


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## SeattleBen (Jul 16, 2020)

Looks like the vid is private from here.


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## ian (Jul 16, 2020)

SeattleBen said:


> Looks like the vid is private from here.



Thanks, hopefully it's public now.


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## SeattleBen (Jul 16, 2020)

It sure is. That's nice looking work. How many hours are you into it?


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## ian (Jul 16, 2020)

Hours, days, weeks, months, who can say at this height of delirium.

Dunno really, though. 6-7 hrs, including all the prep work? Thanks for the compliment.


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## Carl Kotte (Jul 16, 2020)

Great thread as usual Ian. I think I can learn a lot here. From what I can see the knife looks very Carl Kotte in its present condition. I wish you all the best in your effort of making it less so.


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## nutmeg (Jul 16, 2020)

you should try to remove the vertical scratches but it‘s going to be very time consuming and you‘re going to need very coarse stones.
The color left from the uchigumori is good for honyaki.
6k may be too much, mirror gives dangerous scratchy results.
2-3k is somewhat cleaner on honyaki.
Your finger stones are too hard for honyaki. You need very, very, very soft ones. Very difficult to find. I doubt you can find some anywhere.
Hazuya/jizuya finger stones difference works for tamahagane but not for kitchen knives with very hard steel.


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## ian (Jul 16, 2020)

nutmeg said:


> you should try to remove the vertical scratches but it‘s going to be very time consuming and you‘re going to need very coarse stones.
> The color left from the uchigumori is good for honyaki.



I think the vertical scratches you see are from the uchi, actually. They're not that deep. Kipp's original sandpaper scratch pattern was horizontal. It's possible there are some vertical scratches left from the Chosera 800, but that's about it. Or maybe I'm confused. I don't think they're grind marks, though.


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## ian (Jul 16, 2020)

There is a really thin line on the uchi that I can feel when I'm sharpening, though. It causes a very small hiccup when I go over it. It's not really thick enough to dig out or anything, but I did wonder if it could be hurting the finish. I think it's the sort of diagonal one in the middle of the stone.


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## ian (Jul 16, 2020)

Just for contrast, it does look ok when I’m not trying to show the scratches. Here it is indoors with a light coat of oil.


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## Hanmak17 (Jul 16, 2020)

ian said:


> Hi all,
> 
> I've been working on polishing this Kippington 52100 honyaki. When I got it, the geometry was really quite nice for polishing, with only extremely minimal low spots in places that matter, and a lovely convex all over. So, I only really dropped down to a Chosera 800 for the initial work, going lower than that only on a couple spots on the back that won't matter so much for food release, while keeping them convex. Anyway, since the Chosera, I jumped up briefly to Gessh 2k and 6k just to lighten the scratch pattern a bit, and then spent a bunch of time on this uchimugori I got from @nutmeg. I think it's on the coarser side of uchimugoris, although it's the only one I've tried.
> 
> ...




It has been my experience that using a progression of sand paper up to #2500, then moving to finger stones achieves the greatest results. In effect taking a blade up to near mirror polish allows you to see any remaining grind marks or scratches and thus be able to remove them. Once that is complete experimenting with a variety of finger stones allows you to achieve whatever finish you like, if you screw up, just repolish with the highest grit sandpaper and start over. I've done this with several high end knives and love the results. I've also found the knives are far less reactive this way, as the patina covers the entire surface. Stones IMO are good for wide bevels and or very flat blades with little convexity. 

Just an opinion of course.


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## ian (Jul 16, 2020)

Hanmak17 said:


> It has been my experience that using a progression of sand paper up to #2500, then moving to finger stones achieves the greatest results. In effect taking a blade up to near mirror polish allows you to see any remaining grind marks or scratches and thus be able to remove them. Once that is complete experimenting with a variety of finger stones allows you to achieve whatever finish you like, if you screw up, just repolish with the highest grit sandpaper and start over. I've done this with several high end knives and love the results. I've also found the knives are far less reactive this way, as the patina covers the entire surface. Stones IMO are good for wide bevels and or very flat blades with little convexity.
> 
> Just an opinion of course.



Thanks for the thoughts! I might have done that, but I don’t really want a mirror polish on the hard steel, and no fingerstones that I have (or am likely to get) are soft enough to work below the hamon. See @nutmeg’s comment.

Maybe a good look would be to take the whole knife to a very high grit sandpaper polish, and then use fingerstones above the tempering line, but the core would have to really be mirror for the scratch pattern of the sandpaper not to clash with a fingerstone finish above the hamon. And a completely sandpaper finish removes all contrast so you can’t see the hamon. Also, after spending hours on a previous knife, I hate hand sanding. It’s much easier on my body to use a bench stone. Sword polishers (and fancy people like nutmeg) seem to use bench stones on convex geometry all the time, and in my experience it wasn’t very hard to get pretty uniform contact. It may well be that the convexity is making it harder for me to get a uniform finish, but on the other hand I’m not getting any faceting at all, which is the usual problem you see if you’re struggling with flat bench stones on a convex knife.

I assume you mean the knife is less reactive because the finish is higher on the blade? If so, I agree that that is the case. I’m not sure what you meant by “the patina covers the whole blade”, though.


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## Hanmak17 (Jul 16, 2020)

I can't confirm but suspect that they are using stones on the flat sections around the convex geometry, or simply using finger stones on whole blade. I don't see how you can create an even finish on a convex surface with using a flat surface. Either that or the stones need a concave surface reasonably symmetrical to the convex surface of the knife.


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## Hanmak17 (Jul 16, 2020)

ian said:


> I assume you mean the knife is less reactive because the finish is higher on the blade? If so, I agree that that is the case. I’m not sure what you meant by “the patina covers the whole blade”, though.



When the grind marks and abrasions are removed from the surface of the knife (surface is more uniform), then refinished with hazy kasumi finish, the reactivity is significantly reduced in my experience. Did this with both of my Kato's and allowed a nice patina to reform. They are largely non reactive now to onions and tomatoes. If I leave juice on the blade it will obviously react but the smell and discoloration even after extended periods of prep work is essentially gone now.


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## ian (Jul 16, 2020)

Hanmak17 said:


> When the grind marks and abrasions are removed from the surface of the knife (surface is more uniform), then refinished with hazy kasumi finish, the reactivity is significantly reduced in my experience. Did this with both of my Kato's and allowed a nice patina to reform. They are largely non reactive now to onions and tomatoes. If I leave juice on the blade it will obviously react but the smell and discoloration even after extended periods of prep work is essentially gone now.



Yea, I just didn’t get the remark about patina. It’s definitely true that the higher grit your finish the less reactive your blade. Nooks and crannies in the surface give more total exposed metal, and it’s probably easier for microscopic amounts of juices and stuff to get trapped in them or something.


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## ian (Jul 16, 2020)

Hanmak17 said:


> I can't confirm but suspect that they are using stones on the flat sections around the convex geometry, or simply using finger stones on whole blade. I don't see how you can create an even finish on a convex surface with using a flat surface. Either that or the stones need a concave surface reasonably symmetrical to the convex surface of the knife.



No, they use them on the convex portions too. The finish on my knife in the OP is relatively even, it’s just scratchy, and the knife is convex all the way spine to edge while the finish is straight from bench stones. The point is you wobble the knife while you work, as described in the OP. Apparently some sword polishers even use convex _stones _when polishing, since if you’re wobbling it’s not important to have a flat surface, and convexity of the stone prevents faceting and keeps you from having to flatten too often. See this thread. There’s a vid halfway down.






Domed whetstones?


In sword sharpening it seems common practice to use convex or domed whetstones. Does anyone have any experience using these? And can anyone explain why its beneficial?




www.kitchenknifeforums.com


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## M1k3 (Jul 16, 2020)

You could also try making an artificial "finger stone". Look through here for some possible ideas (I guarantee no actual results. Haven't done any of this, yet)? Polishing knife to emphasize banding


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## ian (Jul 16, 2020)

M1k3 said:


> You could also try making an artificial "finger stone". Look through here for some possible ideas (I guarantee no actual results. Haven't done any of this, yet)? Polishing knife to emphasize banding



Yea, it’s a good idea! I’ve tried that with the dremel pads on this knife, actually, with both uchi mud and King 800 mud. Didn’t do a whole lot, and even the pad was giving slightly visible scratches. Hmm. The King 800 mud in particular seemed to decrease the contrast, and made the finish look a bit worse. I should probably keep trying though.


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## M1k3 (Jul 16, 2020)

Etch it?


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## nutmeg (Jul 16, 2020)

I guess if you go 1000, 2000 and uchi strictly parallel to the length of the blade, the surface should be more even.
Using finger stones is possible but only when the finish is top after the uchi. It's like final make up.
Anyway, horizontal is the way to scratch


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## ian (Jul 16, 2020)

nutmeg said:


> Anyway, horizontal is the way to scratch



Huh, really? Interesting. I was scratching vertically since it seemed easier to wobble in the direction perpendicular to the convexity. Isn’t it easier to have faceting with heel to tip strokes?


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## nutmeg (Jul 16, 2020)

ian said:


> Huh, really? Interesting. I was scratching vertically since it seemed easier to wobble in the direction perpendicular to the convexity. Isn’t it easier to have faceting with heel to tip strokes?


not sure you can get faceting on a honyaki, even at coarse
grit


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## ian (Jul 16, 2020)

nutmeg said:


> not sure you can get faceting on a honyaki, even at coarse
> grit



Hmm, I’m confused. The finish off the Chosera 800 looked faceted in places initially when I was working on it, but smoothed out with more and more wobble strokes. Obviously I have a lot to learn.

I’m also confused about the strokes along the length of the blade. When I do a wobble stroke vertically, the knife contacts something like a rectangular section of the blade. If I do a stroke heel to tip, it seems like each stroke will contact a very thin strip of the knife, so will be much less efficient. It’s like trying to polish a cylinder with a flat stone. If you go around the cylinder with the stone, you’ll make lots of contact. If you go along the length of the cylinder, you’ll contact in a single line. Seems less efficient?

I guess I was also trying to mimic what the sword polishers do, and they go perpendicular to the edge, at least in the couple vids I’ve seen. (Maybe I’m missing the finishing steps or my vids were misleading.)

maybe I should shut up about theory and go try it.


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## Nemo (Jul 16, 2020)

M1k3 said:


> Etch it?


Did this inadvertently with my Kip the other day. I think it was from onion. Hard steel went that whitish grey. Soft steel much darker.


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## nutmeg (Jul 16, 2020)

Finish on swords has been done horizontally for centuries so it should work for us as well


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## ian (Jul 16, 2020)

I must be watching the wrong videos. Or maybe I’m watching them set the geometry, not polish it.


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## nutmeg (Jul 16, 2020)

coarse stones for geometry, vertical, then diagonal and finally horizontal (#1000-1500 and above)


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## ian (Jul 16, 2020)

Really interesting. Thanks for all your help!


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## Iggy (Jul 17, 2020)

Hi,

just a question in this context (as I have a similar project):

Has some of you tried a slurry, made with the Wa-Powder from JNS?
Have the powder (both grits #1000 #2000) here but could not find the courage to try it 


Thanks.

Iggy


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## ian (Jul 17, 2020)

Funny, there’s a very different quality to the lengthwise finish. Right now it looks super streaky, as expected, but I can see that it will probably be better in the long run. I’ve tried a number of different motions. Mostly, I’m now doing one hand on the tang, on hand sort of flat on the knife blade, fingers pointing toward the tip, exerting pressure in the desired places. At some point, I tried putting a 2x4 to one side of the stone, braced on the other side with some cast iron, so that I could keep the spine in contact with the wood and keep my scratches perfectly horizontal. Found this kind of annoying and not all that helpful. I also tried laying the knife down on a silicone mat (over a wet towel) on the counter and using the uchi like a giant fingerstone. This was working decently, although it’s more tiring and the scratches seem deeper, probably due to the increased weight.

Any thoughts on how to better stabilize my movements to get more perfectly horizontal scratches? I was also maybe thinking of reinstalling the handle so that half of the tang is exposed, just to give some extra weight and grip down there. Currently it’s hard to control from down there since it’s so far from the balance point of the blade. 

I didn’t drop down to 1000 like nutmeg suggested, since it already had an uchi vertical finish, but probably I should have? Seemed weird to recreate the deeper scratches I’d erased. But maybe I should do it that way on the other side.



Iggy said:


> Hi,
> 
> just a question in this context (as I have a similar project):
> 
> ...



Never tried their wa powder. But I’d imagine it would work somewhat similarly to using stone powder from your own stones, without all the effort to get it? Dunno though, maybe theirs is special. I haven


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## ian (Jul 18, 2020)

Hmm, how does one get the lengthwise finish to be less streaky? More mud, less pressure, changing the line of contact on each stroke so that your polishing starts on one stroke near the spine, then the next stroke a little more toward the edge, then more and more, and then starting back toward the spine when you reach the edge? 

Having more trouble getting the streaks out with lengthwise strokes than widthwise.


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## lemeneid (Jul 19, 2020)

ian said:


> Hmm, how does one get the lengthwise finish to be less streaky? More mud, less pressure, changing the line of contact on each stroke so that your polishing starts on one stroke near the spine, then the next stroke a little more toward the edge, then more and more, and then starting back toward the spine when you reach the edge?
> 
> Having more trouble getting the streaks out with lengthwise strokes than widthwise.


I’m no pro, but this is how I do it. You can lay the stone perpendicular or parallel depending on how you need to get the scratch pattern laid out. Also one side of my stone is convexed while the other is totally flat, which makes it more versatile depending on the grind of your blade.

Beware though, it’s not for the faint of heart, you will lose a lot of metal and stone doing this as you constantly have to flatten and I use quite a bit of pressure so it is very aggressive. But definitely faster than sandpaper.

Also helps if you have a vice to keep the knife in place, doing this free handed can be tiring and you’re prone to errors. And at higher grit, about 1500 and above, I find it might be good to start having a sanding block and diamond compound, it can speed up the mirroring process quite a fair bit.


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## ian (Jul 19, 2020)

Ah, so you are holding the stone on top. Interesting. I tried that briefly a few days ago, but reverted to knife on top. It did seem potentially easier to get a straight scratch pattern with the stone on top.


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## lemeneid (Jul 19, 2020)

ian said:


> Ah, so you are holding the stone on top. Interesting. I tried that briefly a few days ago, but reverted to knife on top. It did seem potentially easier to get a straight scratch pattern with the stone on top.


Yup, but its a total stone destroyer, only do that if you don't mind wrecking it and changing your stone, you can see from the last picture I posted, how convex the stone got after. But it is EXTREMELY fast in shaping your blade and putting very straight scratch pattern.

Would love to know how the pros do it. Think most do with knife on top?

This is mine after 1000 grit sandpaper. Only did the heel half where you can see it’s almost mirror, but the tip half can use a little more work  and my kanji is almost disappearing now


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## ian (Jul 19, 2020)

lemeneid said:


> Yup, but its a total stone destroyer, only do that if you don't mind wrecking it and changing your stone, you can see from the last picture I posted, how convex the stone got after. But it is EXTREMELY fast in shaping your blade and putting very straight scratch pattern.
> 
> Would love to know how the pros do it. Think most do with knife on top?
> 
> ...



Hmm, I haven’t noticed massive dishing. Lots of mud, though. Confusing. Maybe I’m just using the stone surface more evenly than when I sharpen, so it’s less dishing and more just wearing away evenly. I’m probably not using as much pressure as you are either.

With the stone on top, I find the scratches are generally a bit deeper, perhaps because the weight of the stone translates to a lot of extra pressure.

I ended up just doing more knife on top strokes with a lot of mud to try to get it as even as possible. Then I happened to find this “fingerstone” (or would you call it a hand stone, given its size?) in my cabinet that I never use. I have no idea what it is, but it happens to work well on the hard steel! It doesn’t scratch up the finish like the others I was trying, and is making it more even. Looking forward to trying as well with some other soft fingerstones that are arriving tomorrow. I’m not really going for mirror, so I’ll probably just keep going with fingerstones for a bit and then call it done.


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## Luftmensch (Jul 19, 2020)

You can work with scratches!

When I thin my daily drivers, I feel compelled to go through the process of refinishing the blades. I do a brushed finish on the flat of the blade, and a haze on the bevel. Getting a good satin brushed finish can almost be as maddening as any other type of polish. It depends what standard you hold yourself to!

Before getting to the brushed finish, you can polish the surface to the final grit level you want, or even one git higher. At that point I have found good success doing more or less what @lemeneid said. Knife below and abrasives above. Put the aesthetic scratches on the blade by doing very controlled passes across the surface. I even use ruler to ensure I am keeping the passes straight. The lighting in this photo is super harsh and revealing:






This is the front quarter of a 210mm gyuto. The brushed finish is as straight as I could manage! Drove me mad... had to do many resets. On average I would consider this finish to be 70% perfect. Suits me fine. Again, it is a knife that is to be used. It is a dirty 5000 on the core steel, a painfully done 600 grit brush on the face and a dirty fingerstone finish on the bevel. It looks quite different in normal lighting. The brushed finish is quite bright and shiny, the bevel is a nice dull kasumi and the bevel is mirrorish. There are some nice contrasts.

On uchigumori (bench and finger stones)... Sword polishers have a collection that they can match to the steel they are working with. As @nutmeg pointed out, yours is likely too hard. It is easy to get hung up on tradition. Anything that gets the job done is fine by me! You don't _have_ to use uchigumori . As you noted in your previous post, you may find stones better matched to your knife. I have a Shobudani stone that reliably leaves a lovely scratchless kasumi finish. It may be too cloudy for hamon though. Experiment with what you have in your tool kit!


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## lemeneid (Jul 19, 2020)

Luftmensch said:


> You can work with scratches!
> 
> When I thin my daily drivers, I feel compelled to go through the process of refinishing the blades. I do a brushed finish on the flat of the blade, and a haze on the bevel. Getting a good satin brushed finish can almost be as maddening as any other type of polish. It depends what standard you hold yourself to!
> 
> ...


That looks amazing! 

I think to make it even more perfect to your high standards you would have to use some guided system to keepthe scratches as straight as possible and pressure as consistent. And before that the blade face would have to be as flat as possible so you wouldn't get any low or high spots which would make the scratch pattern too deep or shallow.

I'm really curious though, how did you manage to keep the scratch pattern on the bevel so consistent and almost parallel to the edge.


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## ian (Jul 19, 2020)

Luftmensch said:


> You can work with scratches!
> 
> When I thin my daily drivers, I feel compelled to go through the process of refinishing the blades. I do a brushed finish on the flat of the blade, and a haze on the bevel. Getting a good satin brushed finish can almost be as maddening as any other type of polish. It depends what standard you hold yourself to!
> 
> ...



Hey, that is a cool finish. Got any pictures in other light?

You do have to use an uchimugori if it’s your only polishing stone and you don’t want to get another. 

But the fingerstone is making things much better. Here’s the current state of the art, but more work needs to be done.


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## Luftmensch (Jul 19, 2020)

lemeneid said:


> That looks amazing!



Thank you kind sir! ☺



lemeneid said:


> I think to make it even more perfect to your high standards you would have to use some guided system to keepthe scratches as straight as possible and pressure as consistent. And before that the blade face would have to be as flat as possible so you wouldn't get any low or high spots which would make the scratch pattern too deep or shallow.
> 
> I'm really curious though, how did you manage to keep the scratch pattern on the bevel so consistent and almost parallel to the edge.



Kind of strange... For some reason I got hung up on getting the scratches nice and uniform but decided to neglect the kasumi (not a perfect haze) and bevel (scratchy mirror). I guess thats why I would down grade the overall finish? Ultimately those lower areas get scratched so I figured the extra effort would be wasted.

Like you observed, start with a flat surface. My 'cheat' was to use a ruler. I have a little block of wood. Maybe about 20-30mm wide and 10mm long. I would wrap the sandpaper around that and guide it with the ruler. You're spot on! Changes to pressure or veering off the guide would change the scratches. The entry and exit points were also big causes of wobble!

I got pretty even scratches on the kasumi by guiding the finger stone with two or three layers of vinyl tape. That tape is quite nice to use as it is thick but can be stretched into nice sweeping curves.


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## Luftmensch (Jul 19, 2020)

ian said:


> Hey, that is a cool finish. Got any pictures in other light?



Not yet! It is the dead of the night here... I couldn't get angles with artificial illumination that looked natural. I'll see if I can remember tomorrow  



ian said:


> You do have to use an uchimugori if it’s your only polishing stone and you don’t want to get another.



Hehehe... _maybe_? You could revisit the mud idea? I havent used a dremel pad. I've used the furry side of tanned leather - it seems to be forgiving and scratch free. 



ian said:


> But the fingerstone is making things much better. Here’s the current state of the art, but more work needs to be done.



Looking great! Keep at it. I am loving the adventure.


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## inferno (Jul 19, 2020)

I dont have any honyakis!

But having "polished" about 15 or so bevels and then a few whole knives including 2 of my own single bevel mono santokus i have some input on polishing.

i feel for clad blades you get good contrast from 800 or so. the shapton pro1k, naniwa pro 800, king 1k hyper, all good (but the hyper creates silver scratches). 

moving up i feel the naniwa pro 2k is good for contrast. the shappro is quite good but much harder to get the wanted result.

then i feel clean cut kit 4k is good. also glass gray 6k will work. but you have to work the slurry.

----------------

also tried an uchigumori and 2 different coticules. the difference in end result with uchi vs 800-2k-4k is minimal, but with the synths you have to kinda know how to do it to get the wanted result. with the uchi you just put the blade on there and polish away. there can only be 1 result. and its the same result every time. i would say my uchi creates a hazy finish comparable to maybe 2-4k somewhere. probably around 3k in shapton numbers.

the coticules (i have newer mined ones) they create this hazy finish, its much finer than the uchi, but still hazy. not a mirror. maybe twice as "fine". these are also very easy to use since there can pretty much only be one end result. and you get an even finish just like with the uchi.

-------------------

i have also "mirror polished" a few knives, with stones. and if you dont have like 5-10-20 extra hours to spend maybe this is not for you.
anyway i flattened and polished 2 single bevel santokus. carbon steel at maybe 62-63hrc or so. and with stones you really have to erase all previous scratches before you move up in grit. otherwise those will shine through.

even after the shappro 12k and SS12k they are not really really mirror imo. from some angles they are but from other angles you can see all the scratches.

i dont know what stone would be needed to create a true mirror finish but it must be in the 15-30k range imo. and it would probably take forever.

------------------

if one wants a good mirror polish i think different sandpapers from C to F, maybe up to 2-3k would be the fastest, and then finish it off with green Cr-oxide or 0,5 micron diamond on wood/felt/leather/whatever you have. best is to have the knife stationary and rub the compound on there. use double sided tape.

-----------------

for a general good polish i'd say the uchi is the fastest and most user friendly. and that 3k or so finish hides scratches. its at least twice as fast as anything else imo. and its gonna look good. with good contrast. almost no skill required either to get a good result.


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## inferno (Jul 19, 2020)

for a user knife that one wants to keep nice and just touch it up every month or so. i'd say uchi is the best, then maybe coticule.

for synths 800 or 2k naniwa pro.

for mirror - crox on something soft.

with all these you get fairly repeatable results. fast.


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## Majbjorn (Jul 23, 2020)

Great thread! Learnt alot.


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## Luftmensch (Jul 23, 2020)

ian said:


> Hey, that is a cool finish. Got any pictures in other light?



Better (but not brilliant) light... Shiny things are hard to photograph!


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## naader (Jul 29, 2020)

ian said:


> Hi all,
> 
> I've been working on polishing this Kippington 1095 honyaki. When I got it, the geometry was really quite nice for polishing, with only extremely minimal low spots in places that matter, and a lovely convex all over. So, I only really dropped down to a Chosera 800 for the initial work, going lower than that only on a couple spots on the back that won't matter so much for food release, while keeping them convex. Anyway, since the Chosera, I jumped up briefly to Gessh 2k and 6k just to lighten the scratch pattern a bit, and then spent a bunch of time on this uchimugori I got from @nutmeg. I think it's on the coarser side of uchimugoris, although it's the only one I've tried.
> 
> ...



the fingerstones could be from a hard uchi or they could be too thick. You want your fingerstones thin as possible


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## kayman67 (Jul 30, 2020)

I do the stone "sanding block" routine, starting with Naniwas 220 (best use of it like that) and also the scratch lines. They do actually improve food release a bit compared to "mirror" blades. I've tested this with identical knives, just finished differently.


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## ian (Jul 30, 2020)

naader said:


> You want your fingerstones thin as possible



I’m a little confused by this, actually. I mean, I don’t really want them as thin as possible, because if you thin them to nothing then they’ll just disappear in half a minute when you start polishing. I hear people say “credit card thickness”, which makes sense. But more importantly, why do you want them so thin? People say “thin until it’s almost flexible” but it’s still stone, so I can’t imagine there’s a significant amount of flex at credit card thickness levels. It’s easier to feel in contact with the knife if it’s thin, I suppose. I think I’ve heard people say to also break the stone across the center once it’s thin, which potentially would increase the area on a convex bevel and make your work go faster. But unless you do that, I’m not sure why we are stressing so much about being thin. Other ideas?


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## Luftmensch (Jul 30, 2020)

You use the thin stones for the thin knives... usubas  ... And the thick stones for thick knives.


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## ian (Jul 30, 2020)

Now it makes sense!


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## valgard (Jul 30, 2020)

ian said:


> Hmm, I haven’t noticed massive dishing. Lots of mud, though. Confusing. Maybe I’m just using the stone surface more evenly than when I sharpen, so it’s less dishing and more just wearing away evenly. I’m probably not using as much pressure as you are either.
> 
> With the stone on top, I find the scratches are generally a bit deeper, perhaps because the weight of the stone translates to a lot of extra pressure.
> 
> ...


glue something as backing and thin that to less than 1mm thickness before using it. Finish with some powder mix with oil and a rolled cotton to smooth out the last details


ian said:


> I’m a little confused by this, actually. I mean, I don’t really want them as thin as possible, because if you thin them to nothing then they’ll just disappear in half a minute when you start polishing. I hear people say “credit card thickness”, which makes sense. But more importantly, why do you want them so thin? People say “thin until it’s almost flexible” but it’s still stone, so I can’t imagine there’s a significant amount of flex at credit card thickness levels. It’s easier to feel in contact with the knife if it’s thin, I suppose. I think I’ve heard people say to also break the stone across the center once it’s thin, which potentially would increase the area on a convex bevel and make your work go faster. But unless you do that, I’m not sure why we are stressing so much about being thin. Other ideas?


Stones do deform better around the small curves when they're very thin, I thought I had sent an answer here, but if you glue a backing and grind it below 1mm you can also break them by rolling them on a convex or concave surface, that allows for a much more even finish.
Regardless, you might want to smooth out the last details of the finish with some powder mix in oil, apply with a rolled cotton and go at it for a while.


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## valgard (Jul 30, 2020)

Well, ***? And now the answer I sent yesterday just appeared in my new post?


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## ian (Jul 30, 2020)

valgard said:


> I thought I had sent an answer here, but if you glue a backing and grind it below 1mm you can also break them by rolling them on a convex or concave surface, that allows for a much more even finish.



Yea, that makes sense to me. Something in me is still skeptical that they deform enough to make a difference without cracking. Probably this just speaks to my inexperience, though.... Gotta keep on polishing and see it for myself now!

This knife project is on hold, though. Looks decently good atm, but I got sick of polishing it and just wanted to use the damn thing!


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## valgard (Jul 30, 2020)

ian said:


> Yea, that makes sense to me. But I'm still skeptical that they deform enough to make a difference without cracking. Probably this just speaks to my inexperience, though, and if you say they do, then I should believe you. Gotta keep on polishing and get some experience, I suppose.
> 
> This knife project is on hold, though. Looks decently good atm, but I got sick of polishing it and just wanted to use the damn thing!



When you're back at it, do side by side testing with thick and under 1mm finger stones and you should get your own answer. I have done it and the answer is that it makes a difference for me but YMMV.


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## valgard (Jul 30, 2020)

However, if the bumps and irregularities in the grind are too much I go even thinner and crack them


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## Luftmensch (Jul 30, 2020)

ian said:


> Something in me is still skeptical that they deform enough to make a difference without cracking.



I think your intuition is correct.



ian said:


> I don’t really want them as thin as possible, because if you thin them to nothing then they’ll just disappear in half a minute when you start polishing.



Lets explore this function by taking it to its limit 

I'll make the axiomatic statement that stone has _zero_ flexibility. When you glue backing material to a stone, it allows the stone to crack while holding the fragments together. The thicker the stone, the larger the surfaces at the crack interfaces (resistance to moving relative to each other). As the thickness of the stone approaches zero (or the gap between stone particles becomes infinitely large) you approach the flexibility of the backing material!

Corollary: thinness has no benefit beyond ergonomics unless you are fragmenting it on a backing material


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## valgard (Jul 30, 2020)

Luftmensch said:


> I think your intuition is correct.
> 
> 
> 
> ...


and cows are spheric...


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## Luftmensch (Jul 30, 2020)

valgard said:


> and cows are spheric...



to the zeroth order


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## 4wa1l (Jun 26, 2021)

Bumping this thread as I've started on the "fun" journey of polishing a differentially hardened 26c3 knife. Just wondering if anyone has tried using a naniwa dressing stone (600 grit) or similar to get a starting satin finish?


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## Luftmensch (Jun 27, 2021)

4wa1l said:


> get a starting satin finish



Satin finish isn't a precise term in this community (I don't think). I interpret it as something like a sand blasted finish (aka fake kasumi). Perhaps the subtle difference being that satin is 'frosty' and kasumi is 'cloudy'... That is just my interpretation! 

Semantics aside... I havent used the naniwa dressing stone for polishing (or anything for that matter). My gut feeling is that it would be slow - which isn't necessarily a bad thing. The problem you are likely to have, is blade flatness. Since the dressing stone is a large chunk, it wont deform to any lumps and bumps on the knife surface. Unless your knife is locally flat, you may struggle to get an even finish using it. You could potentially cut a slice off and superglue it to a kitchen towel - make your own finger stone! 

Are you working towards a kasumi haze... or a brushed finish? If you are going for brushed... it is far easier! You can use high grit wet & dry without worrying about knife flatness.


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## M1k3 (Jun 27, 2021)

Luftmensch said:


> or a brushed finish? If you are going for brushed... it is far easier! You can use high grit wet & dry without worrying about knife flatness.


400-~1k sandpaper leaves this kind of finish. Past 1k starts getting shiny instead of "brushed" looking.


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## Luftmensch (Jun 27, 2021)

M1k3 said:


> 400-~1k sandpaper leaves this kind of finish. Past 1k starts getting shiny instead of "brushed" looking.



For sure!

I can't remember which grit I used in posts [#36 and #44 above] - I think I like the 400~600 region. Above that, like you say, the metal starts to get pretty shiny - especially if you over work the paper (the abrasives break down into finer particles). If you want nicely defined scratch/brush marks, I recommend using fresh paper without any water (more aggressive). You use a moderate amount of paper (as it wears out quickly) doing this but you get the nicest lines.... At this point you _shouldnt_ be polishing out any lower grit marks. If you want 600 grit brush lines, you should already have a >600 grit surface. When you switch to dry paper, you are only trying to control the final 'brush' marks....


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## M1k3 (Jun 27, 2021)

Luftmensch said:


> For sure!
> 
> I can't remember which grit I used in posts [#36 and #44 above] - I think I like the 400~600 region. Above that, like you say, the metal starts to get pretty shiny - especially if you over work the paper (the abrasives break down into finer particles). If you want nicely defined scratch/brush marks, I recommend using fresh paper without any water (more aggressive). You use a moderate amount of paper (as it wears out quickly) doing this but you get the nicest lines.... At this point you _shouldnt_ be polishing out any lower grit marks. If you want 600 grit brush lines, you should already have a >600 grit surface. When you switch to dry paper, you are only trying to control the final 'brush' marks....


There's also sanding a step above your desired finish. Then going over it the grit you want. 

I've also heard that some makers use worn out 400 grit sandpaper


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## 4wa1l (Jun 27, 2021)

Yeah I'm looking a for a brushed finish. I just don't have the patience for a full polish.

I was mainly hoping that a stone might be less work than constantly refreshing sandpaper but I think you're right about struggling to get an even finish. It's already a slog but looks like I'll just have to do it little by little with the sandpaper. I do have a very fine jnat nagura stone that I quickly tested out. It's not fast enough to remove the coarse scratches but it did bring out a surprising amount of contrast in the hamon and gave a fairly even finish. I'm pretty sure I'll use it as I near the end with some good slurry built up.

Thanks for all the tips! I'll post up a picture when I'm done (or have had enough).


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## Luftmensch (Jun 27, 2021)

M1k3 said:


> There's also sanding a step above your desired finish. Then going over it the grit you want.



Definitely. If using sandpaper - I just tend to over work the grit I am on before moving to dry paper - the paper breaks down quite quickly. But for honyaki... you are probably right....sanding one level above your final grit is probably worthwhile.




4wa1l said:


> Yeah I'm looking a for a brushed finish. I just don't have the patience for a full polish.



Easy! Just use sandpaper I say.... it is cheap. You can get a 100mm by 5 metre roll for ~$15 dollars from Bunnings. I bend small strips around a thick piece of (3-5mm?) leather to give the paper a semi-rigid backing. It is flexible enough to deform into subtle dips but stiff enough to give you a wide contact area. It is also stiff enough to follow guides - if you want super straight/parallel brush marks you can follow a straight piece of scrap wood etc...



4wa1l said:


> I was mainly hoping that a stone might be less work than constantly refreshing sandpaper



You do seem aware... but at the risk of over-explaining (in case you dont do much DIY stuff): use the sandpaper like it costs you $0.00003 per mm^2... because it does  ... It only cuts fast for about 30 seconds (probably less!!) before you need to move to a fresh piece. Your time is worth more than the exhausted sandpaper! Overall you don't lose too much time if you pre-cut strips of paper... if you keep using fresh paper it can be quite aggressive and fast....




4wa1l said:


> I'll post up a picture when I'm done (or have had enough).





Definitely... I would love to see progress!


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## captaincaed (Jun 27, 2021)

M1k3 said:


> There's also sanding a step above your desired finish. Then going over it the grit you want.


This worked well for me. Also, sanding both d directions at the final step on the same grit helped ensure the finish was even.


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## M1k3 (Jun 27, 2021)

4wa1l said:


> Yeah I'm looking a for a brushed finish. I just don't have the patience for a full polish.
> 
> I was mainly hoping that a stone might be less work than constantly refreshing sandpaper but I think you're right about struggling to get an even finish. It's already a slog but looks like I'll just have to do it little by little with the sandpaper. I do have a very fine jnat nagura stone that I quickly tested out. It's not fast enough to remove the coarse scratches but it did bring out a surprising amount of contrast in the hamon and gave a fairly even finish. I'm pretty sure I'll use it as I near the end with some good slurry built up.
> 
> Thanks for all the tips! I'll post up a picture when I'm done (or have had enough).


Stones actually work really good to remove scratches. The drawback is it's really hard to do the whole blade.


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## tostadas (Jun 29, 2021)

I've been playing around with a few things recently that have shown some interesting results. Havent tried it yet on the honyaki, but that will be next when I have some time. 

Sandpaper up to slightly higher grit than I want to finish at, so in my case I went up to i think 1200 or 1500. Then etch with hot vinegar and/or hot coffee. Still figuring out which gives better results. Then I lightly brushed the finish with some king 800 mud on a scrap of felt cloth.

If you are doing sandpaper alone, it's hard to end up with a matte finish. It would be more like a brushed finish.


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## cotedupy (Jul 8, 2021)

Luftmensch said:


> You can work with scratches!
> 
> When I thin my daily drivers, I feel compelled to go through the process of refinishing the blades. I do a brushed finish on the flat of the blade, and a haze on the bevel. Getting a good satin brushed finish can almost be as maddening as any other type of polish. It depends what standard you hold yourself to!
> 
> ...



That is superb. Love it!


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## Luftmensch (Jul 10, 2021)

cotedupy said:


> That is superb. Love it!



Thank you kind sir!

The best part is, you don't need a fancy workshop or tools/stones. Or much skill really.... just patience and stubbornness


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