Is japanese natural awasedo grit really friable?

The question comes up every once in a while about the friablity of the grit particles in Japanese natural stones. Sometimes it goes like this from our fine partner here Mr. Honer Simpson.

HonerSimpson said:

But you are assuming that the grit breaks down....

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The common narrative on the subject has always been both here and in Japan that, Yes, the grit is friable. The next question will arise. Well can you prove it? And then, because it would be so hard to prove by the aveage guy sitting at their kitchen table making a mess while his wife or girl or boy friend isn't looking, will just ignore the original statment along with the inevitable follow-up question.

No use in asking the heavy hitters like Shapton or Naniwa to prove it for us, although they are the only ones who have the funding to prove it one way or the other. Not in their best interests. How about a Masters Degree theisis by my son? Sorry dad.

What would be a model to prove the fact, friable or not friable. Here is my first attempt photographed at 300x.

I lapped a level 5 (9) hardness awsedo with a worn out #600 Atoma diamond plate, let the slurry dry and harvested a small amount of slurry, transfered slurry to a clean glass sheet.

Honed a Boker razor on 1,000 King, took photo.

Final finished bevel to optically bright scratchless finish on 10,000 grit Naniwa, took photo of polished bevel.

Honed same polished razor on awasedo with wetted slurry from above, took photo of bevel Jnat scratch pattern.

Re-honed razor on Naniwa to bright polish, did not take photo of renewed bevel.

Rubbed optically scratchless blade on same pile of wetted slurry sitting on glass plate, took photo.

Repeated process with Naniwa, stock photo. Wetted slurry, photo, Naniwa, stock photo, wetted slurry, photo. Done

I don't think that I proved anything, yet.

Alex

This is a scratch pattern test, not a sharpest edge test.

Very nice Alex, thanks for posting the images. I seem to remember seeing electron microscope images of slurry that looked like clumps of plates/bits, so I'd imagine the breaking of these agglomerated "things" accounts for the friability.

Cheers, Steve

Interesting approach. One variable introduced into the equation is new metal particles blended into the slurry that might adjust the cutting characteristic of the slurry after being worked by the Boker.

It might be friable. It might not be friable.
I do think that at least some of it is - there certainly is geological proof that its possible.

But - If someone asks me to prove that it is, I ask them to prove that it isnt.

That's a clever approach. I recall Bart Torfs did similar experiments with Coticule slurry on glass and found that the cutting power diminishes with use (and that it produced a poor edge). Of course we know Coticule garnets do not break down, although the phylosilicates in Coticule slurry do.

There will never be "proof" in these experiments, only "evidence"
Proofs are for mathematicians.

Does Jnat slurry break down into flying spaghetti monsters?

HonerSimpson said:

That's a clever approach. I recall Bart Torfs did similar experiments with Coticule slurry on glass and found that the cutting power diminishes with use (and that it produced a poor edge). Of course we know Coticule garnets do not break down, although the phylosilicates in Coticule slurry do.

There will never be "proof" in these experiments, only "evidence"
Proofs are for mathematicians.

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Misdirection is a clever approach when it's executed well. ^That - was not executed well.

Do you have proof/evidence/indicators/examples/theorems - that prove that Jnat slurry doesn't break down?

SliceOfLife said:

Does Jnat slurry break down into flying spaghetti monsters?

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Yes - it does.

Here's a high-magnification dark-field microscope image.

So... is that scratch pattern from the thinned-out jnat photo more desirable?

I ask as someone who only knows kitchen knives and synthetic water stones. I think in theory the finer the scratch pattern, the better (for razors, not not for chef's knives necessarily). The Naniwa looks familiar... I don't know what I'm looking at in the jnat photos.

Yeah, I need a honing guru, clearly!

HonerSimpson said:

That's a clever approach. I recall Bart Torfs did similar experiments with Coticule slurry on glass and found that the cutting power diminishes with use (and that it produced a poor edge). Of course we know Coticule garnets do not break down, although the phylosilicates in Coticule slurry do.

There will never be "proof" in these experiments, only "evidence"
Proofs are for mathematicians.

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We don't know if Coticle garnets lose cutting efficacy. If the sharp edges are blunted during honing then the result would be diminished cutting, but not necessarily a finer edge. Bottom line, someone needs to invest in an electron microscope and put these speculations to bed.

Didn't someone take SEM images and determine that something was breaking down, but people argued over whether or not it was the abrasive particles?

Yes. Some people said it was only the binders, not the abrasives breaking down.
http://www.japanesenaturalstones.com/jns-grit-fines-and-hardnes/

SliceOfLife said:

Didn't someone take SEM images and determine that something was breaking down, but people argued over whether or not it was the abrasive particles?

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There were images that showed no clear difference before and after, and arguments ensued, users were banned, thread closed.


I posted these two images in an another thread. Optical images, but particles are resolved. Either "no evidence of break down" or "evidence of no break down" or "BS" depending on your preconceived notions.

Here's the pic from JNS

The feel of the slurry at the beginning is very different at the middle or end of the particular slurry progression. DOes anyone want to argue the point that this isnt so? The edge is better after the slurry goes through this process. Breaking or not. WHats the difference?Maybe the steel mixed in does something, I dont know nor do I care, the result is whats important. And a worked slurry produces a better edge than a not worked one.

buca3152 said:

The feel of the slurry at the beginning is very different at the middle or end of the particular slurry progression. DOes anyone want to argue the point that this isnt so? The edge is better after the slurry goes through this process. Breaking or not. WHats the difference?Maybe the steel mixed in does something, I dont know nor do I care, the result is whats important. And a worked slurry produces a better edge than a not worked one.

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I don't believe anyone is arguing about the "effect" or the "observations" made during honing. My concern is that the explanation of what happens on the microscopic scale should not be very difficult to verify by microscopy and yet it has not been done. If slurry particles go from 3 micron to 1 micron, say, that would be obvious under any quality microscope.

You are correct that it doesn't matter, except to people who are naturally curious and feel the need to have an explanation.

buca3152 said:

The feel of the slurry at the beginning is very different at the middle or end of the particular slurry progression. DOes anyone want to argue the point that this isnt so? The edge is better after the slurry goes through this process. Breaking or not. WHats the difference?Maybe the steel mixed in does something, I dont know nor do I care, the result is whats important. And a worked slurry produces a better edge than a not worked one.

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Thank you for stating this. As a person new to honing on JNATS, sometimes not knowing is bliss for me. Case in point, I started out using a microscope all the time on my edges. Now, I use a loupe more often and my senses of hearing, eyesight and feel while the blade is on the stone to tell me what is happening. Do I believe that my slurry breaks down? Yes. Can I prove it to anyone else here or another "un named forum full of condescending experts"? No. Do I care? No.

Why?: Because no one else shaves with my edges for money. And, of the very few who have shaved with an edge that I honed for free or for a nominal fee, I got no complaints either because they were a. satisfied or b. They were being too nice to me.

I for one don't like to see these conversations degrade into nonsense. It's certainly good for the newbies like me to read these conversations and learn but, I find it disheartening to read some of the quips and barbs being exchanged between people whom I have had respect for. If I want that, I can go to another forum to get berated, chastised and made to feel inferior.

We don't have that here thank goodness. And sometimes, even the most experienced honers get too involved in minutia and lose track of the goal, the smoothest sharpest edges.

Besides, everyone knows that it's really all about Unicorn farts that smell like Skittles anyway.

Frank

Well as long as we are all in agreement about the end result, this is all academic then. And I realize the thread was specific. Just want to stress the fact that the process works and the results prove this. One day we may understand exactly what happens. Until then, keep working the slurry! LOL.

Particle size distributions are difficult to measure unless you are working with uniform shapes and general sizes to start with. I have seen similar "disagreements" trying to quantify coffee grinds and fines produced by different grinders using SEM and laser diffraction techniques both of which are flawed.

I have never honed with JNATS (but sadly for me and my wallet interested in the topic) but perhaps what we are looking at rather than "breaking down" slurry particles to smaller sizes a polishing of the particles as the steel repeatedly passes over them such that smoother surfaces are produced. These surfaces would feel differently and subsequently work the steel with a more refined cutting or polishing contact.

Just a thought that might satisfy both sides of the discussion.

Steve56 said:

Very nice Alex, thanks for posting the images. I seem to remember seeing electron microscope images of slurry that looked like clumps of plates/bits, so I'd imagine the breaking of these agglomerated "things" accounts for the friability.

Cheers, Steve

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Steve
Are you suggesting the grit particles in their native state are bonding together to make super particles, and that when those break apart this is what we feel is the breakdown of the slurry. Maybe not the breakdown of individual particles but the breakdown of the super particles.

That's a clever approach. I recall Bart Torfs did similar experiments with Coticule slurry on glass and found that the cutting power diminishes with use (and that it produced a poor edge). Of course we know Coticule garnets do not break down, although the phylosilicates in Coticule slurry do.

Click to expand...

Honer
You seem to know something about this. The Phylosilicates sheets you refered to, I did the Wikipedia search and they mention that these silica particles can be bound by the Van Der Waals effect. Does this bonding create the super size particles? What's your take? On the grit particle or the clay binders that might be facilitating a bond.

The last photo in my group above with the thinner dried slurry sample just more or less shows more clearly the individual grit particle "bites" to the steel. I do not know how one could document any one individual grit particles transformation from whole to half the size. Hitachi might be able to pull this off but so far I am at a loss.

http://www.tulane.edu/~sanelson/eens211/phyllosilicates.htm

Alex