Thread: Is a Coticule Sufficient

Today, most people use their coticule as a finishing hone. For that they moisten it with water (or lather in some instances).
In earlier times there were no good quick man made hones available, and the coticules considered as superior hones, because of their ability to remove metal very fast. For that task a milk like slurry needs to be raised on the stone, usually with the help of a smaller piece of coticule. This works today as well as it did in the old days. BUT, although almost all coticules are good finishers and produce comparable results, the same is not true for their cutting speed in slurry mode. Some coticules are soft and produce an abundant slurry with ease. On the other side of the spectrum, some coticules are quite hard and it is impossible to produce a good dense (but not too dense) slurry on them. On top of that, some coticule-slurries eat metal very rapidly, while others don't. In the old days coticules were triaged during production on speed AND fineness, for razors and scalpels. Or on speed with less attention for fineness, for various other tools.

If you want to do serious bevel-correction with a coticule (besides its task as a finishing hone), you need to make sure to buy a fast one. It's not as is they are seldom, but slow coticules aren't seldom either.

I don't particularly like the different grit ratings that are often quoted on this forum. Maybe from a speed perspective in comparison with a Norton hone they make some sense. But talking about scratch pattern, they don't. The honing particles are the same, whether water or slurry is used and the scratch marks appear the same as well. At least, under my microscope they do.

The downside with using slurry on a coticule is that the slurry doesn't allow the edge to become keener that a certain level. (I believe for the same reason, it is impossible to overhone on a coticule) Once you hit that level, keenness stays constant, no matter how much more metal you remove, i.e. while honing a small chip out. If you take a keener edge than that to a coticule with slurry for about 10 laps, that keenness immediately falls back to the maximum level that coticule allows with the given density of the slurry. The thinner the slurry, the sharper the level that can be reached, but also: the slower the honing process becomes.
I have been able to get very good results, even while honing small chips out, or removing a bit of corrosion, by starting with a good milk-like slurry, and once the bevel was okay again, dilluting that slurry, one drop of water at the time, to the point where it became (almost) nothing but water, over the period of approximately 100 laps. It is not my main honing method (I usually start on a DMT1200), but as we speak, my best shaver so far is honed with that method + a few laps on a pasted paddle strop with CrO.
I don't know if I could have pulled that off when I first started honing. Maybe it's not an ideal path to follow for learning the basic honing skills. But that was not your question.

Bottom line: the right coticule CAN replace my DMT 1200 and anything in between the polishing stage on that same coticule with water. The resulting edges respond very well to a few additional laps on Chromium Oxide.

Best regards,
Bart.

Give Howard a call. Tell him what you want and he will take good care of you.

And if you want, you can use 3M Abrassive Film (1 micron) in between the coticule and the chrtomium oxide.

How can I contact Howard? Is he a member on this site or should I contact him through theperfectedge.com?

At theperfectedge.com you will find both Howard's email eddress and his phone number. If you call him, be prepared to chat for a bit as he is both a fount of information on stones and a charming fellow to speak with. Or you can look him (Howard) up on the member and send him a PM.