Thread: Slurry Dulling

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.

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

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?

Firstly, i have no experience with J-Nats.
Secondly i use slurry as part of a progression from the same stone (Escher) slurry to water only. Same razor gets refreshed on the same stone with water only. At that point if you use slurry my guess would be that you run into "Slurry-Dulling" when your actually just wasting a precious stone. The key is the knowledge as to when the razor needs refreshing.

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

Originally Posted by Steel

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?

Right there ..

If the particles do not break down any farther, then they would be "Floating" the very fin away from the hone
Don't know

Honestly I think it just doesn't make any sense nor does it fit my experience that an edge that is losing steel is getting "Duller" not without coming to the end of the geometry/limits of the edge and creating a failed edge what we call Over Honing



But we are also limiting the term itself to only one stone now... So does the term Slurry Dulling only apply to a Coticule ??? We know other stones can hone using slurries from start to finish also sooooooo

Originally Posted by gssixgun

Right there ..

If the particles do not break down any farther, then they would be "Floating" the very fin away from the hone
Don't know

Honestly I think it just doesn't make any sense nor does it fit my experience that an edge that is losing steel is getting "Duller" not without coming to the end of the geometry/limits of the edge and creating a failed edge what we call Over Honing



But we are also limiting the term itself to only one stone now... So does the term Slurry Dulling only apply to a Coticule ??? We know other stones can hone using slurries from start to finish also sooooooo

Yeah. I can appreciate your theory. I wouldn't discount it too quickly either as it may have some validity to it. In the end it is all theories and personal experiences and if we don't share them we tend to stay inside of our box. By talking about them it challenges everyone to think.

What I still don't quite understand according to the theory of the particles "floating" the edge is how would that cause a shave ready edge to degrade? In my mind, I can't dismiss that many people here (including my own experience) have reported their experience of taking a shave ready edge, raising a slurry, doing some light passes through this slurry, and noticing a marked degradation in the edge. Is there something else going on here, in your opinion? I can't see that a floating edge alone would degrade.

Could it be that both of these theories are correct to some degree? I don't know either but it sure makes you think.

Since some studies seem to indicate that the abrasive grits don't break down...only the binder. Wouldn't raising a slurry be counter productive as it would expose the "whole" boulder causing deeper scratches than the "imbedded" boulders that can only scratch as deep as their exposed height.

That explanation would seem to be born out by the experiences shared here.

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.