Thread: Chamfering the edges on a Coti

Originally Posted by STF

They said they hadn't named it but it is select. It's newly mined not vintage.

I can get special stones like La Vienette or La Latneusse (don't know how to spell that one) but they are expensive and I need more rocks, lotsa rocks

OMG - what happened, I can't stop looking longingly at stones. Have you seen the Ancient Sea Jasper - Purty!

Newly mined from a new vein/layer? Sweet.

I think we're all very interested in some pictures

I couldn't wait so i just had a shave with my fresh coti edge.

I'm a bit disappointed and will kill the edge and keep trying on the same razor to reduce the variables until I have it cracked.

Don't get me wrong, I have had a decent shave and it was obviously a coti edge because that's all I used but it wasn't super keen and smooth.

I had to work to get a decent shave, I will use the razor again tomorrow but strop it on ChroOx. After tomorrow i will start again because I would rather get it really good without the ChroOx, I guess there must be a purist somewhere in my rabbit hole.

Originally Posted by TristanLudlow

Newly mined from a new vein/layer? Sweet.

I think we're all very interested in some pictures

There ya go, the slurry stone wore the print off but that's ok, I took a pic before i used it.

Originally Posted by STF

I couldn't wait so i just had a shave with my fresh coti edge.

I'm a bit disappointed

I know that feeling well enough.

I often make my razor shave ready finishing on my 20K.
Then I add a layer of tape, do some strokes on the 20K, as it cuts fast enough for a secondary bevel, and finish the razor.
This is what I know works for me, so it eliminates all my variables.
If I want a Coticule finish, I then go to a Coticule under running water with a layer of tape to end it.
--

I can advice if you want a good decent shave at first, to try and use the Coticule purely as a finisher and eliminating all the variables.
If I don't finish under running water on my Cotis, I dislike the shave, so there's that.
Probably why my great-grandfather and his father used their Coticule & BBW with oil.

I also find my Coti edge to be very angle sensitive while shaving, as shallow as possible.

I am fortunate that two of my coticules are natural combination BBW/coticule stones. Most of the cotis have a black clay schist backing to stabilize the coti layer. FOr mine, the two layers naturally formed adjacent to one another and blend together.

Like Tristan, I have also found that the BBW can really add to the edge. You can get a decent BBW for considerably less than an equivalently sized coticule, but, like all natural stones, they are not all same. Some are hard and great finishers, others are softer and good bevel setters.

You have to experiment to maximize the edge you get from one. A lot of guys give up on them and stick to the predictable outcomes they can achieve with synthetic stones. Natural stones can be frustrating to figure out, but once you have your stone working for you, I don’t think you’ll be happy with any other edge. My experience anyway.

Welcome to the coti club.

You do not want to lap an Ark with a diamond plate, you will ruin the diamond plate, (rip the diamonds out). But you can ease a corner with a diamond plate under running water for a few strokes without damage. If you need to bevel a corner or remove a chip from an Ark corner, use an old file. You will ruin the file for other work, but old files are cheaper than diamond plates.

Lapping or beveling a slate or coticule will not damage a diamond plate. It is how slates and coticules are lapped and beveled.

I have never heard of not using a diamond plate on slates or coticules and have lapped hundreds on various plates without issue. As said there are those that believe diamond slurry is too course, and a rubber/tomo slurry is probably finer than most diamond slurry, but it depends on the diamond plate, grit and condition of the plate and the stone.

Diamond slurry is just fine and has been use for years on slates, coticules and Jnats without issue and with great results.

Finishing under running water for final finish works very well on most Natural stones.

Did you lap the stone flat and smooth?

Originally Posted by Euclid440

Did you lap the stone flat and smooth?

Yes, I did.

Originally Posted by TristanLudlow

I know that feeling well enough.

I often make my razor shave ready finishing on my 20K.
Then I add a layer of tape, do some strokes on the 20K, as it cuts fast enough for a secondary bevel, and finish the razor.
This is what I know works for me, so it eliminates all my variables.
If I want a Coticule finish, I then go to a Coticule under running water with a layer of tape to end it.
--

I can advice if you want a good decent shave at first, to try and use the Coticule purely as a finisher and eliminating all the variables.
If I don't finish under running water on my Cotis, I dislike the shave, so there's that.
Probably why my great-grandfather and his father used their Coticule & BBW with oil.

I also find my Coti edge to be very angle sensitive while shaving, as shallow as possible.

This morning I had another shave with the same coti edge that disappointed me yesterday except that I added 25 laps on ChroOx.

My shave today was completely different, BBS without much effort.

I will say that I am not satisfied yet, I don't expect to be because I've only had the rock for a couple of days.

The shave was close but just felt sharp, no coti smoothness.

Tomorrow I am going to set the bevel to 12K on synth so I know where I'm at and then add tape and do 30 x-strokes under running water on the coti.

I will probably spend a few days doing that to get a handle on how good I can get the edge. I will then set the bevel again on 1k and continue with the coti. When I eventually have that down I can try the whole progression from bevel set again.

Originally Posted by DZEC

I am fortunate that two of my coticules are natural combination BBW/coticule stones. Most of the cotis have a black clay schist backing to stabilize the coti layer. FOr mine, the two layers naturally formed adjacent to one another and blend together.

Like Tristan, I have also found that the BBW can really add to the edge. You can get a decent BBW for considerably less than an equivalently sized coticule, but, like all natural stones, they are not all same. Some are hard and great finishers, others are softer and good bevel setters.

You have to experiment to maximize the edge you get from one. A lot of guys give up on them and stick to the predictable outcomes they can achieve with synthetic stones. Natural stones can be frustrating to figure out, but once you have your stone working for you, I don’t think you’ll be happy with any other edge. My experience anyway.

Welcome to the coti club.

I am toying with the idea of getting a BBW, basically because I don't have one

I am a bit confused. I have been under the impession that a BBW is coarser than a yellow coti and better for heavier work, maybe bevel setting or restoration

If that is correct and the coti is finer, why will a BBW help in a progression in the normal shceme of things, especially as a finisher?

Originally Posted by STF

I am toying with the idea of getting a BBW, basically because I don't have one

I am a bit confused. I have been under the impession that a BBW is coarser than a yellow coti and better for heavier work, maybe bevel setting or restoration

If that is correct and the coti is finer, why will a BBW help in a progression in the normal shceme of things, especially as a finisher?

A BBW is actually slower on slurry than a Coti on slurry, the BBW also has a higher max keenness.
There's also a popular method of using a coti on slurry and then refining on a BBW with slurry and then to finish on a Coticule with plain water.

A BBW on plain water is extremely slow, much slower than the Coti, its why they usually are used with a very light mist of slurry for finishing.

My BBW edges are never coarser than my Coticule edges, unless my Coti edges are finished under running water, then my Coti reaches a smoother edge.

I actually got much better edges using a BBW unicot method for a long time and couldn't get my Coticules as smooth or as keen.

There was a blind study over at the Coticule forum a while ago, people could hardly discern a top Coticule edge from a finished BBW edge. Half even preferred the BBW skin feel afterwards.

Very interesting read: http://www.coticule.be/heritage.html.../BBW-study.pdf

I have been using mostly my Cotis lately, but will revisit my BBW again soon to make a side by side comparison in the shave.
I think you can achieve very similar results with both stones, I do seem to switch between a BBW and Coti as favorite finsihers.
Lately I got my Coti edges as good as ever and slightly prefer them.

I also had Bart hone up some razors for me IRL and had him giving me pointers,
while the edges were absolutely amazing, I still modified his honing method to suit my preference with the use of dry honing.

Whatever gets you where you want, dry honing on a BBW is something I would like to advise everyone, I think many will be impressed by its capabilities to leave such a keen edge. However I see no need for one if you only have a Coticule on hand. Honing on a Coti dry will do almost the same, but it won't be quite as keen. It'll still give you a perfect edge that you can finish under running water.