How do you evaluate a new JNAT?

[cugel]

A diamond slurry and some circles can sort of tell you it's cutting power, provided the slurry color changes fast enough. I am terrible at judging fineness of stones. After awhile the jnat scratch patterns all sort of look the same to me except in the most refined edges. Use it, use it more, then still more after that.

I have a couple that I have not figured out fully yet. In fact one, an ancient hand sawn soft-ish stone, works best as a pure finisher with water only. A head scratcher for me but that's been my experience. Try everything.

 

[Calou]

One of the most important qualities for me is the tactile feel of the stone. If that was not important to me I would just stick to synthetic stones. The stone does not need to be fast, but speed is a quality metric that will rank the stone in the right direction. So speed and tactile feel is one quality attribute, especially for stones in the mid to upper mid-range.

My Tsushima Nagura bench stone is one example of a stone with good feedback, but i do feel it is a little too slow. I will use it just to mix things up, but i do not feel it is a quality razor stone compared to other options. Good for woodworking tools though.

If there is impurities in the stone that produce deeper striations the stone will not be used for razors. If it is fast it can still be a grate knife stone. But in that case it would need to really rank high in the aforementioned characteristics. I will not spend allot of time "figuring" out the stone if this test fails. You can probably feel if something is "off" quite early.

I do agree that most stones, particularly natural stones need to be figured out with a specific goal in mind. However, i do feel some generalizations can be made about how you approach a JNAT compared to e.g. a coticule.

Some Synth are more pleasant to the touch than some natural ... To my taste.

Yes, used for razors edge and can be used with or without mud, in a wide range of use. Aesthetically more variants at Jnat than at Coticule, I find.

 

[H Brad Boonshaft]

Eliminate as many variables and disregard sellers hype or what the stone looks like. Yes, with Jnats you are/can be paying for looks, quite a lot in some cases, also cut, size and thickness.

Alex Gilmore’s JapanStones ,1k to Jnat finish technique will quickly and easily tell you a lot about the stone’s aggression/speed, finishing ability, potential and range, without all the variables of bevel pre- finish and added nagura grit.

The base stone diamond slurry should easily remove all 1k stria and polish the bevels to a shaveable edge with just the base stone’s slurry with a minimum of laps. A shave test will tell you if it can be refined even more with nagura experimentation.

This is a no B/S stone evaluation.

With diamond slurry you know you are, only honing on the base stone, with any tomo you are including some tomo slurry. Eliminate variables.

Bottom line is you must hone on it and shave off the edge it produces, then add variables with nagura to quantify improvement.

 

[Steve56]

To begin with, flatten and smooth the surface to your desired finish. I use an extremely mellow 600 Atoma that only gets used for the final finish on razor stones. Then I raise a slurry and run a knife, cleaver side, or a worn wedge razor across it. When you’re lapping and surfacing the stone, you’ll get a feel for the relative hardness and speed.

Use a good quality test razor, I like a 5/8 American steel or similar Swedish or French steel razor. The important thing is to use a razor that’s known to take the best of edges. The condition isn’t that importamt as long as it‘s not heavily worn. The steel at the edge should be impeccable, no pitting, devil’s spit, etc. Take the razor up to 8k-12k edge. Check the edge with a loupe, make sure that it’s straight and even.

Raise a thin slurry with a mellow diamond plate so that you have all base stone slurry. I finish on slurry that’s thin enough to see the edge through on the first couple of strokes. If the stone is softer, a hard tomo nagura will work.

Make sure that you have an edge that’s all from the stone in question. Normally I’ll use 2 sets of 20 circles/ellipses followed by 40 edge leading steokes flipping the blade each stroke and decreasing pressure. Re-lace water as necessary to keep the slurry thin. People say don’t count strokes, but my stroke count came from watching the bevel on hundreds of razors and it works for most razors, you might need more on really hard steel and these numbers might be a little more than the minimum on softer razors.

Watch how quickly the slurry blackens, this is your indication of relative speed.

When you’re done rinse the blade and examine the edge with a loupe, note any differences from the 8-12k level. Touch up any areas remaining with coarser scratches, usually the heel and toe as necessary.

Strop and shave, even if it’s a midgrit stone. No pastes of course.

Once you’ve shaved, repeat the above process at 8-12k and finish, then rinse the blade and stone and add about 20-30 light strokes with only clear water. This will let you know if your stone responds well to clear water finshing and can be a very useful thing to know about a stone. Clear water finishing doesn’t work on all stones or equally well, but when it does, it can bump the keenness a good bit if desired.

Then start matching a tomo to it.

 

[JPO]

To begin with, flatten and smooth the surface to your desired finish. I use an extremely mellow 600 Atoma that only gets used for the final finish on razor stones. Then I raise a slurry and run a knife, cleaver side, or a worn wedge razor across it. When you’re lapping and surfacing the stone, you’ll get a feel for the relative hardness and speed.

Use a good quality test razor, I like a 5/8 American steel or similar Swedish or French steel razor. The important thing is to use a razor that’s known to take the best of edges. The condition isn’t that importamt as long as it‘s not heavily worn. The steel at the edge should be impeccable, no pitting, devil’s spit, etc. Take the razor up to 8k-12k edge. Check the edge with a loupe, make sure that it’s straight and even.

Raise a thin slurry with a mellow diamond plate so that you have all base stone slurry. I finish on slurry that’s thin enough to see the edge through on the first couple of strokes. If the stone is softer, a hard tomo nagura will work.

Make sure that you have an edge that’s all from the stone in question. Normally I’ll use 2 sets of 20 circles/ellipses followed by 40 edge leading steokes flipping the blade each stroke and decreasing pressure. Re-lace water as necessary to keep the slurry thin. People say don’t count strokes, but my stroke count came from watching the bevel on hundreds of razors and it works for most razors, you might need more on really hard steel and these numbers might be a little more than the minimum on softer razors.

Watch how quickly the slurry blackens, this is your indication of relative speed.

When you’re done rinse the blade and examine the edge with a loupe, note any differences from the 8-12k level. Touch up any areas remaining with coarser scratches, usually the heel and toe as necessary.

Strop and shave, even if it’s a midgrit stone. No pastes of course.

Once you’ve shaved, repeat the above process at 8-12k and finish, then rinse the blade and stone and add about 20-30 light strokes with only clear water. This will let you know if your stone responds well to clear water finshing and can be a very useful thing to know about a stone. Clear water finishing doesn’t work on all stones or equally well, but when it does, it can bump the keenness a good bit if desired.

Then start matching a tomo to it.

Thanks. This makes allot of sense. I might need to revisit my stones.

 

[Empire straights]

One of the challenges in evaluating a new stone is trying to define what we even mean by the term evaluation. There are very few if any meaningful data points to attempt to extrapolate because when it comes to this hobby everything is unverifiable and at the same time unfalsifiable.
That being said there may be members here that may in fact have put together a more meaningful set of evaluational standards than I have been able to come up with over the years.

As to you assessment, I whole heartedly agree. I subscribe to the "proof is in the pudding" method of evaluating things in my life. I need utility at all points to function throughout my days efficiently. I insist on always using the right tool for the job, though that could be many different tools for the same job but I need results when the rubber meets the road. You could have a thousand Gucci stones but if the shaves feel like broken glass it doesn't do anyone any good, right. That's why the only shave that matters is the test shave. I've had edges that wouldn't hht for anything, but have up amazing shaves. Rub a rock, give it a try. If it doesn't work rub the rock some more. That doesn't work, rub a different rock. Most people will figure out what works best for them during the process. Even if it's minor tweaks. Then you get the mad scientist types like me that likes to try whacky stuff with stone combinations just to see what happens. A beautiful blade that won't cut beard hair is as about as useful as trying to shave with a rose.

 

[Mr Kooby Shemayrew]

How do you approach a new JNAT?​

• Be calm and gentle
• Avoid direct eye contact
• Keep a comfortable distance and respect the JNAT’s space
• Let the JNAT approach you first and let it sniff you.
• Avoid sudden movements which can be threatening.

How do you approach a new JNAT?​

“Yo, baby. These guys all say you is a level five PLUS. Well, I say you is a purfect TEN, baby!”

 

[JPO]

How do you approach a new JNAT?​

“Yo, baby. These guys all say you is a level five PLUS. Well, I say you is a purfect TEN, baby!”

They speak Japanese, you know bro

That would be something like this, if ask you google translate.

「よ、ベイビー。 これらの人は皆、あなたがレベル 5 PLUS だと言っています。 ええと、私はあなたが完璧なTENだと言います、ベイビー！

No wonder why they can be hard to figure out.

Maybe they are all just female...

 

[Mr Kooby Shemayrew]

Japanese, you know bro

Ohhhhhhhhhhhh. Well in that case…..

https://media.tenor.co/images/1a1e05a53821214c20fa8deeccfa1587/raw

They are all purfect.

 

[camoloc]

I just sing...........

"oooooooooh baby I love your ways."

good way to get to know a stone.

seems to have worked for me.

camo

 

[Gamma]

I hone on it. A lot. then I hone some more.
I hone with 'bench mark' stones often, so my reference points are always fresh.

 

[JPO]

I hone on it. A lot. then I hone some more.
I hone with 'bench mark' stones often, so my reference points are always fresh.

I have honed allot with these stones lately. All i know is my new Wakasa and my Nakayama is different then what i have tried before.
The Wakasa feels like a layer of grease have ben mixed in the slurry. To me it feels like the particles in this one is really fine. I honed a Heljestrand razor with it. This edge was one of the smoothest edges i have had from a jnat. It is not super fast, but it does not need to be.

The Nakayama is also a strange one to me. Even after it is lapped there is what looks like shiny nikkel particles, or something imbedded in the surface. It is the fastest jnat i have tried. Those shiny particles are quite similar to what i see in my Shiro Suita.
The stone left what i would consider a crisp edge. I need to use it more with different razors. I have nothing to compare this to. I have a hard Shobudani, but this is just different.

So i guess i should just hone until my hands hurt
I do not have any bench line stones to compare with. The wakasa stone seems to be a really easy stone to use. The other one will require more work.