Thread: Slurry Dulling

The sign of intelligence is constantly wondering so kudos to Glenn for starting this thread. 12 pages worth of discussion and to be honest I can see some common ground between the two camps/ideas

"I don't believe there is any evidence (beyond circumstantial) to prove or disprove either theory. In the end it is all a bunch of guesses based on experience."

'Don't need to engage in this particular controversy - but Steel's observation here applies to quite a few areas of razor maintenance. Stropping comes to mind. The converse is also true - no proof that's not how it works.

If any proveable knowledge ever existed, most is lost to our long wilderness journey to the temple of Gillette. So it can't be a surprise that experience and best guess has to suffice until someone w/ the means & the skills can demonstrate something is actually happening. Do what keeps working until it doesn't work. A generous seasoning w/ humor helps.

For a long time (still largely continuing) - it was thought the edge remained a sawtooth affair getting smaller w/ higher grits. The photomicrographs contest this view - but not entirely. To pronounce 'this is how it works' - we have to do the same work other areas have to do to establish knowledge. In the mean time, I have a lovely Henckels 1/4 grind that's suddenly acting cranky.

I've only heard this theory put forth by one guru and his entourage, and as far as I know, it only applied to coticules or the BBW.

Now, I have no way of proving or disproving the theory, and on the face of it, it makes no sense to me, but lacking empirical evidence, I guess I'll just have to keep an open mind. But, in my world, I pay it no heed.

I read through this thread again to see if my sentiments would have changed over time. My last comment was about slurry dulling being like God. I believe in it.. some do
.. some don't.

Well this is my observations on coticule honing using slurry.

There really is no absolute proof on either side of the argument. I still find if I make a slurry too thick a couple of things happen depending on where in the honing process I am.

1. If at the bevel setting stage with a thick slurry and I make the slurry too thick the sharpness that edge will be able to obtain is notably less keen then it should be. Effectively "limiting" my edge at that point in time.

If I am in the middle of the process, the sharpening part and too thick a slurry is used I have noticed there is no real ill effects other then the need to dilute continually. Which you were doing anyways in the dilucot method.

If you are at the finishing stage and too thick a slurry is used... the edge declines to a rough pulling state... effectively "dulling". This for example would be taking a shave ready edge, making a slurry and honing say 20 laps. Stropping and shaving would give you less then optimal results. This is why the slurry is diluted to water only for finishing. Of course using too thick of slurry on finish would be remedied by dilutions.

Maybe the terms are inconceivable to some... Maybe I am not looking at it the right way. I think it's more of how the slurry is used then the slurry being dulling itself as an entity. The quantity being the problem and the time it's deployed bring another small part. I.e. when to use a thinner slurry and when to use a thicker slurry.

Which is all up to the individual honer to figure out for his own stone.

From what I remember, Jim Rion explained the slurry used on a Jnat breaks down and becomes a finer polisher in the honing process. Admittedly he continued to dilute the slurry until only water was remaining on the Jnat.

Originally Posted by BanjoTom

From what I remember, Jim Rion explained the slurry used on a Jnat breaks down and becomes a finer polisher in the honing process. Admittedly he continued to dilute the slurry until only water was remaining on the Jnat.

I think maybe you are remembering wrong as regards the water-only finishing. As I recall, Jim R heavily advocated for finishing on slurry, not on plain water - as this was the way it was taught to him by his mentor/teacher - a Japanese barber who ran a barber shop in Japan for many years.

Originally Posted by eKretz

I think maybe you are remembering wrong as regards the water-only finishing. As I recall, Jim R heavily advocated for finishing on slurry, not on plain water - as this was the way it was taught to him by his mentor/teacher - a Japanese barber who ran a barber shop in Japan for many years.

I'm not trusting all to memory. Jim, when describing the Shoubundani Aisa that I subsequently bought from him wrote "...it is a decent finisher on water, not too slow, with a keen edge, and on slurry it leaves a smoother cutting edge."
FWTW this hone was sourced from Bo-ohku hones in Kyoto, according to Jim.

Interesting, I remember him always posting about using slurry, maybe that message to you was from before he was taught by the barber. Here's a link from his site, plain water honing isn't mentioned, only adding a few drops of water to the slurry to thin it.

Honing on Japanese Naturals | Eastern Smooth: The Blog

Personally, I've found that some JNat stones produce a better shaving edge with slurry and some produce a better shaving edge with water. One just needs to experiment to see what works better with each individual stone.

eKtretz - What kind of pressure are you putting on the blade while honing and getting a better shaving edge w/slurry?

With slurry I use a tiny bit more pressure than with plain water - really it's more of a torque than it is pressure though. Just enough to be sure that the apex stays in contact well and doesn't accidentally float up too high. It's really stone dependent whether you get a better edge with slurry. I find it's mostly with the harder stones. Also the thickness of the slurry can sometimes make a significant difference to the feel of the edge as well. Some stones even do better with 10 or 20 edge trailing strokes right at the end. There really are a lot of variables with natural stones.