A rather excellent gift from a friend arrived yesterday: four very fine polishing stones. I've only given each of them a quick 2 min try out so far (they need sealing) but it's fair to say I am mildly impressed .
Time to start testing some gear I got lately. The stones are JKI vitrified diamond 1000/6000, Ardennes Coticule and Shapton Pro 12000. View attachment 178395
I am really interested in how you like the Suehiro Debado MD-20 once you have used it for a little bit.Suehiro Debado MD 200 & 1000
A while back i bought a bundle off a fellow canadian and which included 4 stones including the final few mm of a cerax 320 and 3000, i used them several times and unfortunately they have both now broken, however i liked them so much i have now bought brand new ones! So thank you again to @ModRQC !
Also grabbed the 140 atoma with a handle and a bottle of kasumi powder from toshos sale this weekView attachment 178488
You've got some pretty good friends!
Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes.Gesshin 2k straight from JKI
View attachment 176816View attachment 176815
Edit: just used, fantastic stone, took all my knives’ biteness to 10.
I am really interested in how you like the Suehiro Debado MD-20 once you have used it for a little bit.
Cote,Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes. Yes.
If you don’t own this stone, go buy it.
If you want the same bite at 4k, buy the JKI 4k. Then sell all your other inferior sharpening gear (or keep an enormous stone library like me for “historical reasons”, or some other similar claptrap).
Cote,
What type of stones are these, from left to right? You're getting pretty good at the kasumi finishes.
I'm sorry, I meant the three natural stones above the synthetics, two were gray, and the last one was a darker color.Ta! I think I'm getting there, slowly .
They were: King 800, King 1200, a very old Iyo stone, Maruoyama Shiro Suita, stone from my friend (it's an incredibly fine and quite soft mudstone/slate affair, fairly similar to some jnats).
I'm sorry, I meant the three natural stones above the synthetics, two were gray, and the last one was a darker color.
Thanks for the detailed response. You said they were soft, level 3 stones maybe? A friend of mine turned me on to a hardness equation that's pretty accurate.Ah, they were the stones my friend gave me. They're very soft and incredibly fine slate/mudstones. The Pinkish one is the softest, the middle blue-grey one is similar though a little harder you can see at the end of the stone that it's transitioning into the pink stone, and the darker one is harder still and a little coarser. Though all of these are insanely fine-grained and soft stones, that want to mirror jigane and will self slurry with ease.
This is them wet:
View attachment 179505\
View attachment 179504
View attachment 179503
And this is a abandoned quarry, deep in the heart of the Australian bush that he hikes to, to find them. I call it the 'Valley of Death Quarry'
View attachment 179506
Thanks for the detailed response. You said they were soft, level 3 stones maybe? A friend of mine turned me on to a hardness equation that's pretty accurate.
You measure (in millimeters) the length, width, and thickness of the stone --- Multiply the LxW, then multiply the sum times the thickness of the stone. The number you're left with is divided by the weight of the stone in grams, and the number you're left with tells you how hard of a stone you have. You can also divide the weight by the sum you got from the thickness of the stone times the sum of length and width. mm3/g or the latter, g/mm3.
naturalwhetestones.com (scroll down to find an example of the equation so you can work it out for yourself)
Here's a chart to show what the numbers mean:
View attachment 179537
-gray.
I know that Suita stones will kind of skew the results because there's air in the stone due to the su. I think the most accurate test (I've been told) would be a water displacement test. I was under the assumption this test would work with any stone, regardless of composition, but I'm no scientist, that's for sure. So far the results have tracked well with the stones I own, but that's more anecdotal. I think the results would be off a bit (+ or - 5% maybe?) depending on the shape of the stone. A perfect rectangle would be optimal, koppa stones would be a little less accurate, and maybe a corner missing from a stone would also add a little inaccuracy as well, unless you could figure out the volume of the missing part of the stone.This is very interesting to see how they compare Specific Gravity to the Japanese 5 point hardness scale. Ta!
Obviously weight over volume is SG, just they're using mm3 here instead of cm3, so when you shift the decimal point three places to the right you get:
Above 2.80 = 5+
2.65 - 2.80 = 5
2.50 - 2.65 = 4.5
2.35 - 2.50 = 4
2.20 - 2.35 = 3.5
Below 2.20 = 3
---
One thing to bear in mind is that to use SG as a measure of hardness you have to be looking at exactly the same kinds of stones, with the same chemical compositions. You couldn't for example compare an Arkansas novaculite vs a Jnat (mostly mudstones and shales) vs a slate. A trans ark will come in as 4.5 on this scale but is going to be much harder than even the hardest jnats. While the majority of slates are going to be 5 or 5+, even if they're quite soft stones.
I've never actually measured the SG on any of my jnats I don't think. Would be interesting to see how they come out...
I know that Suita stones will kind of skew the results because there's air in the stone due to the su. I think the most accurate test (I've been told) would be a water displacement test. I was under the assumption this test would work with any stone, regardless of composition, but I'm no scientist, that's for sure. So far the results have tracked well with the stones I own, but that's more anecdotal. I think the results would be off a bit (+ or - 5% maybe?) depending on the shape of the stone. A perfect rectangle would be optimal, koppa stones would be a little less accurate, and maybe a corner missing from a stone would also add a little inaccuracy as well, unless you could figure out the volume of the missing part of the stone.
You can divide the weight of the stone (in grams) by the volume sum and get something like this: .0026 g/mm3.
King 700????JNS 6000, Morihei 6000, King 700
Yeah, I’ll let you know what it’s like after I use itKing 700????
The "Jinzo"? IIRC Jon has lauded this as a kasumi polishing stone - not so much an edge stone.Not new sharpening gear, but has anyone got the jki synthetic natural to work?
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