Thread: Slurry Dulling

Originally Posted by AndreGrobler

What do you mean by slurry particles?

What constitutes the slurry of a J-Nat? The answer is slurry particles, or plates. If you want to call them something else that is fine, the name is irrelevant. What matters is how are they composed and the pictures show they have layered structure, like puff pastry. That would indicate that break down happens through shearing predominantly but the way to prove or disprove is to measure the thickness of the plates and that has not been done to my knowledge. I have worked with an SEM quite a bit and am sure that thickness measurement can't be done with that instrument.
In Japan it is accepted fact that the slurry breaks down, since those guys have used those types of stones for thousands of years, I think they probably know what happens to the slurry.

Originally Posted by AndreGrobler

https://scienceofsharp.wordpress.com...ry-break-down/

I honestly wouldnt know... this serms to indicate otherwise... it cannot be called exhaustive however...

Although this is not definitive proof one way or another, after looking at the data/pictures, it is not easily dismissed either. This is very interesting to say the least.

Well the abrasive particles are round hard sillicates the binding agents are what i believe to be smectic clays which are fine plates... those fine plates do break down and change as per that post... it is the hard sillicates that don't. The clays - which due to their polar nature and very fine texture may well be somewhere between suspended and dissolved in the water... are possibly not the particles that abrade, but along with water will become the carrier medium for the sillicates... which seems to agree with what you are saying. The post does measure particles not exhaustively to come to these conclusions...

I may be missing your point though... please enlighten me if i do?

Originally Posted by AndreGrobler

Well the abrasive particles are round hard sillicates the binding agents are what i believe to be smectic clays which are fine plates... those fine plates do break down and change as per that post... it is the hard sillicates that don't. The clays - which due to their polar nature and very fine texture may well be somewhere between suspended and dissolved in the water... are possibly not the particles that abrade, but along with water will become the carrier medium for the sillicates... which seems to agree with what you are saying. The post does measure particles not exhaustively to come to these conclusions...

I may be missing your point though... please enlighten me if i do?

I was talking about how the break down happens IMO, not what abrades. In the end it is all theory-crafting since we have no way of measuring any of the effects to draw positive conclusions. Those stones work though.

Originally Posted by AndreGrobler

https://scienceofsharp.wordpress.com...ry-break-down/

I honestly wouldnt know... this serms to indicate otherwise... it cannot be called exhaustive however...

Ya know I would be much more inclined to add veracity to that entire study if the actual honing had been done by somebody that knew a thing or two about SR honing..

The pics are great.... the hand behind the razor was a mere beginner,,, sorry but that is the hard truth

There was a good experiment done here on SRP a few years back using a Coti and a Coti rubber

The guy that proposed the test theorized that by continuing the break down of the slurry way beyond the normal raising of the slurry by crushing and recrushing the slurry into a creamy state actually created an even smoother edge

I tried it out and I think he might have had a good idea


As to the coti slurry dulling an edge I don't see that,,, but the slurry "LIMITING" the sharpness ??? Yes I see that easily whether that is because of the slurry acting as a cushion that floats the very edge or the slurry bangs into the every edge is in question

My question on this study, (https://scienceofsharp.wordpress.com...ry-break-down/) is, what was washed away during the DI wash, the parts that did break down along with razor swarf?

In conclusion, there is no evidence that the silica (abrasive) particles “break down” or become finer with use. The soft clay binding material of the stone, composed of phyllosilicate material, does break down into individual flakes.

How would they know that only the soft clay binder broke down unless they tested the swarf? And why not test the same slurry, pre worked and after worked?

Yes, I believe the study still leaves the question unanswered.

Originally Posted by gssixgun

PLEASE PLEASE do not simply toss in a link or say "A well known Honester said" I cannot ask a link a question and if that honester isn't on SRP I can't debate with them..

Also this was exactly why I started this thread with that limitation

When you start quoting limited studies then you are not expressing your opinion but somebody else's,,, both of which so far being very limited in nature

Originally Posted by gssixgun

......As to the coti slurry dulling an edge I don't see that,,, but the slurry "LIMITING" the sharpness ??? Yes I see that easily whether that is because of the slurry acting as a cushion that floats the very edge or the slurry bangs into the every edge is in question

+1...That would be my sentiment as well. I routinely hone Sheffield's (as in Virtually Every Sheffield) by going to a finishing Coti with slurry after an 8K shave ready finished blade. I have never noticed any 'dulling effect'. Quite the opposite in fact. The edge is always what I call Sheffield Smooth!

STANDARD CAVEATS: YMMV...IMHO...ETC.

Originally Posted by gssixgun

As to the coti slurry dulling an edge I don't see that,,, but the slurry "LIMITING" the sharpness ??? Yes I see that easily whether that is because of the slurry acting as a cushion that floats the very edge or the slurry bangs into the every edge is in question

Out of curiosity Glen, what do YOU think is going on to LIMIT the sharpness? If not particles hitting the edge what do you theorize is going on and what led you to this theory?