What have I here?

Toff

Well-Known Member
Hi Folks, What have I found? I just made an antique shop find. Definitely vintage it was with a barber group of 1920s razors.I have another coticule. This one is is a two part stone having a maroon bottom like a coticule cemented to a dark finely spotted hone like a coticule and a bit finer grit, almost a marble. The one is wet and the others are dry.

Obviously, I need to learn more about how the photo attach works!
Thank you
~Richard



 

Bart

Well-Known Member
It could likely be a vintage glued Coticule, although there have been a few vintage synthetic hones that mimicked the appearance of the famous Belgian whetstone. But those were usually thicker and closer to the typical 6"X2" format.

If the yellow side releases the typical creamy slurry, and feels smooth while you're honing on it, you can be pretty sure that it's indeed a Coticule. It's impossible to determine the layer of these Vintage stones, because we usually have no idea about which of the several mines it originates from.

These old hones are often oxidized. Chances are high, that if you lap it a bit, that it becomes considerably more cream colored.

Kind regards,
Bart.
 

Toff

Well-Known Member
Thank you Bart!
I just lapped it and it is only slightly more cream coloured. Its slurry is creamy and even a bit finer than my other Coticule. It is the ~190mmx ~40mm size. It hones very well and put a nice edge on a Torrey in about 4 minutes. My dilucot technique is getting better, but still has a long ways to go!
While here, may I ask what is the grit size and use of the maroon bottom layer?
Thank you!
Respectfully
~Richard
 

Bart

Well-Known Member
The bottom comes from Belgian Blue Schiste. That's the rock that surrounds the Coticule veins.
When found close to the actual Coticule layers, the stone has a garnet content of its own, but not nearly has concentrated as within Coticules. If the stone can be used for honing, it is called Belgian Blue Whetstone (BBW). Mineralogical analysis of a couple samples has determined the garnet content within Coticules to be around 20% and that of BBW around 8% (Note that these are averages). Garnets within BBW were reported to be larger.

Whether the backing of your Coticule is suitable for honing or not, I can't tell. It was only meant as a reinforcement for the COticule part. If you're lucky they used blue stone of BBW quality. But it can also be a blue stone of a "sterile" part of the rock. YOu'll have to find that out for yourself. The easiest way to do that is to dull a sharp test razor with one stroke on glass, and see if you can manage to get it shaving arm hair on the Blue. I typically use a bit heavier slurry on the BBW (let's say, the consistency of coffee milk). If you can manage, then some more work on thin slurry (and a number of dilution steps near the end) will get you a good keenness.

There is nothing sensible to say about grit rating. These are natural stones, not compressed blocks of uniform particles, as with synthetic water hones.
Here's some more reading on the topic:
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Kind regards,
Bart.
 

Toff

Well-Known Member
Thank you for answering and directing me to the further explanation. I had read it before but it didn't stick! BBW equals slow and Coticule equals faster.
If I understand correctly; All else being equal; slurry is necessary, water dilution of the slurry is a big if not the biggest factor in the cutting ability of the stone? That being why the Dilucot seems to be a naturally/automatic changing effect sharpening method? The grit size, then can only be guessed at according to the scratches left behind on the metal as opposed/compared to, a ceramic type hone composed of grits of a uniform screened size. (Using the same pressure and angle on the same piece of hardened steel)
The base BBW of this hone is badly compromised but I shall experiment with that of my other Coticule/BBW which seems to be solid and of equal consistency throughout.
Thank you again!
Respectfully
~Richard
 

tat2Ralfy

Well-Known Member
Toff said:
Thank you for answering and directing me to the further explanation. I had read it before but it didn't stick! BBW equals slow and Coticule equals faster.
If I understand correctly; All else being equal; slurry is necessary, water dilution of the slurry is a big if not the biggest factor in the cutting ability of the stone? That being why the Dilucot seems to be a naturally/automatic changing effect sharpening method? The grit size, then can only be guessed at according to the scratches left behind on the metal as opposed/compared to, a ceramic type hone composed of grits of a uniform screened size. (Using the same pressure and angle on the same piece of hardened steel)
The base BBW of this hone is badly compromised but I shall experiment with that of my other Coticule/BBW which seems to be solid and of equal consistency throughout.
Thank you again!
Respectfully
~Richard
Slurry will give your stone the cutting ability you need by releasing garnets, dilution lets us achieve a shaveable edge as the same garnets that cut the steel also dull the edge, so an edge sharpened on slurry alone will not be sharp or smooth enough to shave comfortably with, diluting the slurry allows us to refine the edge, its a bit of a balancing act, and the Dilucot method is a very good way of getting that balance right.

BBW cut slower than Coticule because they have less Garnets, at the same time they dull the edge less as well, meaning that they will give you a sharper edge, the problem comes when we try to refine that edge on the BBW, that is something that we are working on in the Researchers Mess, and I for one have had some wonderful BBW only shaves.

You simply cannot compare the Coticule or BBW to any synthetic grit size, you can roughly find that the speed at which it cuts is similar to a synthetic, and compare the smoothness also, but thats a very subjective thing in its self IMO.
You could look at the scratches on the bevel, but unless the synthetic is comprised of Garnet you are not going to be able to use that visual as a marker.

My Best regards
Ralfson (Dr)
 

Toff

Well-Known Member
The more I learn about the stone, the more fun I have. Thanks to all for editing the information to my halting apprehension.
Respectfully
~Richard
 
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