Thread: Slurry Dulling

To me, a slurry is dependent upon what you are doing and how you are doing it.
Heavy slurries are for setting bevels and repair work. Just because we see tons of awesome slurry on hones to show what they yield does not mean it is always practical to use, FME. Some slurries are to make cutting fast while some are quite light to 'Fill' the hone and make it cut finer. I do think all should be thinned to nonexistent as-used. Some like to leave the broken-down slurry on the hone for next time. Sounds interesting!




Anyway, I think as honing comes to a point (discovered by idiots like myself), pushing mud does not a sharp razor make! Hence, 'slurry dulling' .....JMHO

For me slurry helps cut fast and dilution leads to smoothing the bevel and that process might be perceived as making the edge keener. Honing on slurry I think can be most accurately described as sliding the bevel on round grit particles. The abrasion those leave is in the form of deep groves. When the slurry is gone the bevel slides on portion of the abrasive particles sticking above the hone surface and that results in much shallower scratch pattern from before and thus perceived extra keenness.

I can perceive that!

TBH, I think most synthetic hones and many naturals could be described as honing on slurry to some degree without anything but water. JMO

Originally Posted by mainaman

For me slurry helps cut fast and dilution leads to smoothing the bevel and that process might be perceived as making the edge keener. Honing on slurry I think can be most accurately described as sliding the bevel on round grit particles. The abrasion those leave is in the form of deep groves. When the slurry is gone the bevel slides on portion of the abrasive particles sticking above the hone surface and that results in much shallower scratch pattern from before and thus perceived extra keenness.

This is much like my pet theory>>

I imagine the slurry rolling around under the bevel, but I think that is results in more and more shallow stria because of the rolling sliding action of the slurry..

I also think many more hones than just J-nats actually have a friable slurry and that the little bit that is left as you dilute out fills in between the locked in slurry again creating a smoother bevel..


But it is just a theory and a feel, not something I would say is true


But taking it back to the OP not seeing for any of that would lead to dulling though

Originally Posted by mainaman

perceived extra keenness.

I think you hit the nail on the head. Slurries will smooth out a more keen/crisp edge.

As far as slurry actually dulling, I have only experienced it from one stone. The particles of a Special Stone do not break down.

For me, a slurry is a tool to speed up a bevel set or fine tune a edge on a finisher...but I only use it at bevel set and/or finishing.

That is the theory I have heard about wet sanding a fine finish, the small bits of paint and grit fill the paper and cut a finer, shallower finish. I recently read somewhere that polishing with metal polish where rust is being removed, the rust will aid in the polishing, as an added abrasive and not to switch to a clean cloth but to use the dirty, rusty part.

If the edge is very fine, and the bits are hard, even suspended in water, but then they are not suspended/floating, more like lubricated. I can see the slurry impacting the edge, at the same time you are still polishing the bevel and edge so it is a wash and hopefully you do more polish than impact dulling.

Add to that, thick slurry, more abrasive than water lubricated and or non-friable slurry and you could be damaging the edge as you are honing especially as it dries out. Now, if you can envision that plain paper can damage/dull an edge, certainly so could a thick slurry, which is why we dilute slurry to clear water or least thin milky finish slurry. When we look at SEM photos, edges are never laser straight.

Isn’t that the theory/ argument of diamond plate slurry vs Naugras?

A lot depend on the stone/slurry, the operator/pressure and the progression/experience of thinning the slurry.

Originally Posted by gssixgun

Ok then why

Why do you take an edge that is slightly off the mark that needs a Re-fresh and "Start" with a light slurry, re-form (sharpen) the edge and dilute out (how far depends on your Coti) to a shave ready edge...



I have heard that theory a few times but it doesn't quite hold up..

Well a couple of things come to mind. The first is maybe I am not understanding you fully. When you ask "why?" I have to say that, like you, I don't know or have proof. I only know that has been my experience. If I take a shave ready edge and make even a slight slurry on MY coti it doesn't max out and get sharper. Only on clear water. Why, I do not know. Your theory is as good as mine. Maybe better.

As for the second part. If my razor is slightly off or needs a refresh I personally don't mess with a slurry and dilute it. I just use water only and bring it back. That's me and my stone though.

Now I am using an all Arkansas progression so thats a different animal altogether.

Originally Posted by mainaman

For me slurry helps cut fast and dilution leads to smoothing the bevel and that process might be perceived as making the edge keener. Honing on slurry I think can be most accurately described as sliding the bevel on round grit particles. The abrasion those leave is in the form of deep groves. When the slurry is gone the bevel slides on portion of the abrasive particles sticking above the hone surface and that results in much shallower scratch pattern from before and thus perceived extra keenness.

My slurry experience begins & ends with the coticule only; with that said,,,,,

I only slurry the coticule to increase the cutting power,,,, once I have achieved the edge I want at this point of the progression,, the slurry is removed by running water & the surface lapped a few strokes with the 1200 DMT, this removes any abrasive particles or inbeded swarf in the surface,,, I want a clean, smooth, water only surface for my final edge.

If I were to revisit slurry after my final water edge, then for sure I loose my edge,, "Could this be slurry dulling???"

I think that anyone who experiences dulling while using slurry, has their method, "Bass Aacwards"

Originally Posted by Hirlau

I think that anyone who experiences dulling while using slurry, has their method, "Bass Aacwards"

Hmmmm That may be the most profound statement of the thread so far

One thing I've noticed is that if you reply to this thread the Glen will thank you. What a generous soul.

Seriously though, I've nothing to add to this post but it's interesting to follow and read.