Questions regarding grinding knives for better polishing

Kitchen Knife Forums

Help Support Kitchen Knife Forums:

M1k3

Diamond -> Coticule 👌
Joined
Jul 28, 2018
Messages
10,375
Reaction score
18,683
Thumbs down to hollow grinds on kitchen knives. #unpopular
Love the way my Munetoshi cuts. But I'd say it's concave because he uses a wheel, not because it was supposed to be concave though.
 

captaincaed

(____((__________()~~~
Joined
Aug 29, 2017
Messages
3,564
Reaction score
6,146
Location
Pacific Northwest
The amount of time you must sink into this process is the answer for “why don’t Japanese makers work more in fancy exotic super hard steels”. At least it’s part of the answer.
 

captaincaed

(____((__________()~~~
Joined
Aug 29, 2017
Messages
3,564
Reaction score
6,146
Location
Pacific Northwest
Pushing through on these kinds of things has been one of my biggest internal struggles. I make the "oh ****" mistakes when I'm fatigued, either mentally or physically, and it's taken a bit of time to know when to wrap it up for today and move on to something else for a bit.
Zen and Motorcycles had a good line to the effect of “don’t work tired, you’ll just work your own problems into the project.”
 
Joined
Aug 27, 2019
Messages
2,786
Reaction score
5,780
The amount of time you must sink into this process is the answer for “why don’t Japanese makers work more in fancy exotic super hard steels”. At least it’s part of the answer.
Well it would be irrelevant if they are sanmai, like almost every user of ZDP and HAP40/SG2 does sanmai with soft stainless cladding. Plus not like those are made for kasumi polishes anyway...
 
Joined
Jan 23, 2023
Messages
597
Reaction score
1,308
Yeah it was mainly let's take the cheapest Y. Tanaka AS I can find and make it fancy. I bought a mirror finished one a few days after that, did a light kasumi on it and I'm not touching it again. The stock finish on that KU one was pretty...not great. Sandblasted kasumi over rough grind lines.
So I will back @jedy617 on the stock finish.

Maybe it’s because I’ve tasted the rainbow with some really nice knives, but the sandblasted kasumi really does not look great at all and I’m not super into the KU either.

I can see why you ended up rage polishing for hours - it distinctly gives off a diamond in the rough vibe.

Can anyone suggest the most effective and efficient process for replacing the sandblasted kasumi on the bevel with a more natural looking ‘fake’ kasumi without trying to flatten the concave grind on the stones?

I have sandpaper, micromesh, Flitz and stone powder etc, just not sure what the progression from start to finish should be.
 
Joined
Aug 27, 2019
Messages
2,786
Reaction score
5,780
My best bet is going up to like chosera 800-3k and then I have some tosho kasumi powder that I like to mix with some uchi powder I have, and then micromesh sponge it on.
 
Joined
Jan 23, 2023
Messages
597
Reaction score
1,308
I don’t have a king/chosera, only a Shapton 1k and Morihei 3k at those grits - I assume they would be fine?

And what would you actually be trying to achieve in that first step with the stones? I would be going at it for a while before I started making contact with the sandblasted bevel and I don’t want to sacrifice any height/mess with the edge if I can help it.

Is there a way of doing this without using stones?

Tosho don’t ship to the UK at all currently due to kitchen knives being turned away at customs a few times, so I’m limited to Morihei natural stone powder. Where do you get your uchi powder from? Is it worth it?

@JuniperGhosts I hope you don’t mind me asking these questions here - I think they’re still relevant to your original post though. Maybe you could rename the thread ‘The concave grind/Zahocho KU Tanaka AS rehab thread’ :D
 

natto

Senior Member
Joined
Jan 13, 2015
Messages
353
Reaction score
114
Location
Wilhelmsburg.de
Beyond a visual look, why are they doing this? I don’t understand this process and am looking for an explanation
This Question popped up here and there with polishing. I am thinking of how to keep an all day knife nice and good cutting? Start from there.

With a hamaguriba grind, like on single bevels life becomes easy. Finger pressure at the bevel sharpens the edge, at shinogi sharpens the upper bevel. Clean up, sharpening and work polish may be done in minutes. Sounds like dream.

But life is never easy. How do I get from A to B? With improved performance? Its just a dilemma, and a wonderful playground. :)

Thank you @jedy617
I appreciate your posts. Some of us will learn from your experience, like me.
 
Joined
Aug 27, 2019
Messages
2,786
Reaction score
5,780
I don’t have a king/chosera, only a Shapton 1k and Morihei 3k at those grits - I assume they would be fine?

And what would you actually be trying to achieve in that first step with the stones? I would be going at it for a while before I started making contact with the sandblasted bevel and I don’t want to sacrifice any height/mess with the edge if I can help it.

Is there a way of doing this without using stones?

Tosho don’t ship to the UK at all currently due to kitchen knives being turned away at customs a few times, so I’m limited to Morihei natural stone powder. Where do you get your uchi powder from? Is it worth it?

@JuniperGhosts I hope you don’t mind me asking these questions here - I think they’re still relevant to your original post though. Maybe you could rename the thread ‘The concave grind/Zahocho KU Tanaka AS rehab thread’ :D
Forgot where I got my uchi powder from. Yeah you could definitely try with stone powder without any stone work first. Basically what I tend to do is get the bevels 90% done on stones and sort of blend the finish together where the low spots are with the powder. No reason you couldn't try "painting" over the stock finish.
 
Joined
Mar 3, 2020
Messages
651
Reaction score
664
It helps to have soft backing like hard felt blocks, cork, or fine micro-mesh pads to even things out. King 800's are cheap mud monsters that I find good to even out a working polish easily. Or, if you have a natural stone you like for edges, take some of the slurry and use that.
 
Joined
Oct 5, 2015
Messages
1,033
Reaction score
1,758
Location
North of MSP
So I will back @jedy617 on the stock finish.

Maybe it’s because I’ve tasted the rainbow with some really nice knives, but the sandblasted kasumi really does not look great at all and I’m not super into the KU either.

I can see why you ended up rage polishing for hours - it distinctly gives off a diamond in the rough vibe.

Can anyone suggest the most effective and efficient process for replacing the sandblasted kasumi on the bevel with a more natural looking ‘fake’ kasumi without trying to flatten the concave grind on the stones?

I have sandpaper, micromesh, Flitz and stone powder etc, just not sure what the progression from start to finish should be.
Using a sandpaper progression up to about 3K, then diamond pastes above 3K to buff out the sandpaper marks, then using a pad and j-nat powder is probably the most straight forward way to get what it seems like you're hoping for, on a concave bevel.
 
Joined
May 12, 2023
Messages
361
Reaction score
737
Location
Philadelphia
Using a sandpaper progression up to about 3K, then diamond pastes above 3K to buff out the sandpaper marks, then using a pad and j-nat powder is probably the most straight forward way to get what it seems like you're hoping for, on a concave bevel.
Just curious, I’ve done the sandpaper part up to 2-3k but with diamond paste, what cloth / brush would you use? Microfiber, simple sponge?
 
Joined
Dec 15, 2017
Messages
2,192
Reaction score
7,308
Location
Texas
Just curious, I’ve done the sandpaper part up to 2-3k but with diamond paste, what cloth / brush would you use? Microfiber, simple sponge?
I use felt pads like you’d put on the bottom of furniture feet. Hard enough to be effective and precise and soft enough to conform to a concave surface
 
Top