Thread: Q about coticule

Thx.
Will lapping remove inclusions if any?
And if not, will inclusions damage an edge?

I'm not the biggest proponent of lapping natural stones. If your coticule appears to be flat to the naked eye, then it's likely fine. With a good X stroke, the point of contact between the hone and the razor will constantly change and it'll be fine. I'd be more concerned about chamfering the edges so that the edge doesn't get damaged.

You don't need to lap out the inclusions unless they adversely affect the razor.

Originally Posted by ofelas

Thx.
Will lapping remove inclusions if any?
And if not, will inclusions damage an edge?

Lapping takes off a very thin layer of material, usually using a pencil grid as a guide. If the inclusion is no deeper than the material removed it will also be removed. I have a couple of coticules with inclusions. Once lapped the inclusions did not negatively effect the honing with mine. I would say it will depend on what the inclusion consists of and you won't know until you try a razor on it.

Originally Posted by jaspah

First time I got my vintage natural combo coticule it sat unused for over 40 yrs so it collected dirt and dust and it seemed to be glazed, so I lapped it.
But I was just looking up some info and I read that a Coticule is a non porous stone and couldn't get clogged.
Does this mean the metal of your razor stays on the stone instead of going in and that it remains in your water and you can just wash it away?
So the honing of your razor itself cannot cause glazing of the surface by filling it with the metal of the razor?

I have a few old coticules of which the surfaces were glazed, probably from sharpening using oil. The stones were useless for honing in the shape they were in, the surfaces packed with old metal.

Lapping restored the surface to useable condition. Honing with water, these stones now perform just as they should.

I've been using the poor man's coticule for some time: balsa lapping blocks with diamond and chrome oxide grits. Does anyone have experience with both approaches, and an observation of which is superior?

Originally Posted by prestonmcconkie

I've been using the poor man's coticule for some time: balsa lapping blocks with diamond and chrome oxide grits. Does anyone have experience with both approaches, and an observation of which is superior?

I'm not sure if I am understanding your question. If you're asking about the difference between a coticule and balsa with abrasive mediums or between diamond paste as opposed to chrom-ox on balsa ? I've used diamond paste to improve a sharp edge (on balsa) and I've used chrom-ox on felt to smooth out a harsh edge. That is the limit of my experience with those. I've never tried sharpening a dull razor with paste on balsa. I could do it with a coticule but I'm not sure about the balsa and paste.

I mean, is a coticule better for finishing a blade, than are the balsa blocks treated with lapping paste?

Originally Posted by prestonmcconkie

I mean, is a coticule better for finishing a blade, than are the balsa blocks treated with lapping paste?

I would say yes it is better for finishing a blade. OTOH, if you took an already sharp blade to a coticule I don't think you would get it sharper than you would if you took it to the diamond paste on balsa. That will get a razor wicked sharp IME. Just IMO.

Also, I've never tried paste or chrom-ox on balsa for anything other than refining an already sharp blade. So it may be possible to sharpen a dull blade using them. A coticule seems to me to give a comfortably sharp edge. IOW, it won't be harsh. Than is what I've found anyhow.

Originally Posted by Ieronymus

I have a few old coticules of which the surfaces were glazed, probably from sharpening using oil. The stones were useless for honing in the shape they were in, the surfaces packed with old metal.

Lapping restored the surface to useable condition. Honing with water, these stones now perform just as they should.

My grandfathers coticule was in that shape as well, now it's purdy and clean