Your thoughts on Coticule stones

[Rusty Blade]

To begin I have never used a Coticule stone. The more I read about them the more I struggle to see the advantage of using a Coticule. For example, how is a Coticule more advantageous than say a Naniwa progression to hone or refresh an edge. What is the grit equivalent of a Coticule? Advertisements for Coticules I have read say they range from 4k to 8k some some with or some without slurry.

I am interested to hear your thoughts on this subject. What is your experience? When do you select a Coticule to work an edge?

 

[M14Shooter]

I like a Coticule edge on some of my Sheffield blades.But their is a learning curve.Synthetic stones are easier to learn on.I tend to use synthetic stones up to 16K.Then I choose a finishing stone to impart what type of edge I feel like off a natural stone.

 

[musicman980]

Coticule edges, along with most any natural stone edge, are very different from synthetic edges. To me a coticule edge is much much smoother and easier on the face than any synthetic edge I have tried. There is no grit rating for any natural stone, but people do make attempts to categorize. I like a coticule edge for a daily shaver since it is so easy on the face.

 

[Njguy1977]

Coticule edges, along with most any natural stone edge, are very different from synthetic edges. To me a coticule edge is much much smoother and easier on the face than any synthetic edge I have tried. There is no grit rating for any natural stone, but people do make attempts to categorize. I like a coticule edge for a daily shaver since it is so easy on the face.

I couldn’t agree more, even tho there is no grit rating I can always get a comfortable shave from a coticule. If I want to step up the edge a bit I will use lather on the coti and do super light passes or break out my green thuri or surgical black ark to bump the edge a bit. A coti edge really doesn’t shine until you do 20 passes on linen and about 40/50 passes on leather. After that it should pass a HHT no problem. My coti edges I can get a blade to tree top about 1/2” above the skin on my arm. It’s how I test every blade before and after I shave.

Larry

 

[RumpleBearskin]

I just bought my first coticule (a hand-sized bout since the entry price for 8x3 select was too high). I've used it only once. That was on a razor that I had had trouble with on my synthetics. The result off the coti was excellent. And the process of working on one stone with progressive dilution of the slurry goes deeper into the "art" of honing, IMHO. Great fun and great results.

 

[stone and strop]

Coticule vary greatly.
I have one that is extremely coarse and one that is extremely fine.
Given you have an exceptional specimen, the shaves rival an Escher with even more comfort. Good luck in finding that one!
Its a crap shoot. More so than any other natural species IMO.

 

[musicman980]

My coti edges I can get a blade to tree top about 1/2” above the skin on my arm. It’s how I test every blade before and after I shave.

Larry

That's almost exactly how I test my edges too! Tree top at 1/2 inch and I'm good to go. Not that I've tested 100's of coticules or anything, but I've never had a coti I couldn't shave off of.

Coticule vary greatly.
I have one that is extremely coarse and one that is extremely fine.
Given you have an exceptional specimen, the shaves rival an Escher with even more comfort. Good luck in finding that one!
Its a crap shoot. More so than any other natural species IMO.

What odds constitute a crap shoot?

 

[Rusty Blade]

Hmmmm...sounds like I may need to get myself a coticule stone.

 

[Bowmaker]

My first coticule really challenged me. It took a couple weeks of honing and experimenting before I had an edge that was keen enough. I have purchased a few more since then and the learning curve wasn't nearly as steep. Not sure how lucky I am but the few that I own all produce decent edges.

 

[SliceOfLife]

I buy almost exclusively vintage coticules. I've had maybe 10 modern ones or so. Modern ones varied from ok to decent finishers mostly, with the exceptions being from the expensive/desirable veins.

Of the vintages... which number in the hundreds:

I've had 3 Coarse ones... as in not finishers. Midrange hones... 25+ Micron size garnets. Never had a modern this coarse, but I've had one that came REALLY close (was barely in the next group)... I think it was a La Nouvelle Vein.

I've had maybe 1-2 dozen that were ok/meh finishers. A little less than half the modern coti's I've tried fall in here.

Then the vast, vast majority, (a couple hundred or more) that were decent to good. Most vintages fall in here. In my (limited) experience maybe half of the modern stones fit here as well.

Then maybe 2-3 dozen that are notably better than average finishers... maybe just a hair behind an Escher. I've had two moderns that fit in here.

Then around 10 that are excellent finishers... equal to an Escher or arguably better with certain razors. Never had a modern fit in here.

 

[ajduplessis]

I settled on 3 different vintage coticules and they all give great edges with various degrees of effort. Its not a magic bullet but if you get lucky getting good ones they are easy to use and produce very, very comfortable edges. If you intend to produce the worlds sharpest edge then they are not my choice. I have not yet used a vintage coti that was disappointing, but some modern ones are indifferent.

Coti is typically a pre finisher in my progression.

 

[iamryan25]

To begin I have never used a Coticule stone. The more I read about them the more I struggle to see the advantage of using a Coticule. For example, how is a Coticule more advantageous than say a Naniwa progression to hone or refresh an edge.

The advantage of the natural stone versus the synthetic stone in this comparison would be the natural stone would likely produce a result that feels more comfortable to use on skin when compared to the synthetic stone. The synthetic stone would likely produce a result that "feels sharper" but also is more likely to cause irritation or cut skin.

What is the grit equivalent of a Coticule?

Mixed grit, user adjustable by moderating pressure and slurry content.

The garnets on average are about the size of a red blood cell, but can be smaller or larger, and stones have a mix of particle sizes instead of just one particle size. Even though the spessartine garnet is the abrasive that coticules are known for, the phyllite matrix is made up of other abrasives like quartz and mica as well.

Sometimes people measure scratch pattern depth and width to offer a comparison between synthetics and natural stones, the coticule abrasives are said to penetrate 1-3 microns deep but leave a wider scratch pattern than would a synthetic abrasive penetrating at the same depth.

The abrasives have a different shape, so particle size doesn't tell the whole story.

Advertisements for Coticules I have read say they range from 4k to 8k some some with or some without slurry.

With water only a coticule is a finishing stone. The user adjusts how deep the abrasives penetrate by adjusting their pressure and maintaining slurry-free surface water.

With a slurry generated by a slurry stone a coticule becomes a much coarser grinding stone.

What is your experience? When do you select a Coticule to work an edge?

I use coticules for personal use and almost exclusively with straight razors, some of my knives get the occasional Belgian treatment.

I have handled a couple dozen vintage coticules and over a hundred modern examples. The modern stones are mined from a location where vintage mining sites were reclaimed. I think Bart Torfs does well explaining the differences in his article on his site Is there a difference between "Vintage" Coticules and recently mined ones? - home of the famous Belgian Coticule Whetstone - http://www.coticule.be/faq-reader/items/vintage_vs_recent.html -- his website is a solid resource of information for coticules that many coticule enthusiasts appreciate very much.

Coticules can have different recipes for sharp from stone to stone and the challenge is that other people will not be able to simply tell you the recipe for your unique stone. You'll need to sort out the recipe to find sharp for that particular stone.

Even though I have heard about their use in a commercial environment, I wouldn't suggest that over other options.

They're easy enough to use with water only, probably easiest after a synthetic 8000. But, I would consider a coticule to be more of an advanced level stone when compared to synthetic stones.

In my opinion, these stones are ideal for hobbyists willing to spend time learning a stone and those that enjoy a comfortable shaving edge.

 

[Alum of Potash]

I settled on 3 different vintage coticules and they all give great edges with various degrees of effort. Its not a magic bullet but if you get lucky getting good ones they are easy to use and produce very, very comfortable edges. If you intend to produce the worlds sharpest edge then they are not my choice. I have not yet used a vintage coti that was disappointing, but some modern ones are indifferent.

Coti is typically a pre finisher in my progression.

I agree that a coticule is pre-finisher for the most part from my experience. The way I use it is after a 3k synth, with just water, the 3k perhaps playing the role that a slurry would play. Usually, a coticule edge is not close enough for my beard, and I've had the same experience in trying coticule edges from others. What is needed for me afterwards is either stropping on a linen or leather strop lined with the red Solingen crayon paste or honing on Welsh purple slate used with sewing machine oil.

One way I've been able to bump the edge up off a coticule has been to use shaving cream on it towards the end of the honing session. Perhaps more cushion there equates to less pressure, giving credence to the claim of coticule honing maestros who urge that there should be "no pressure" at the end of honing with it.

 

[cugel]

coticules are a lot of fun to use. just a pleasure to hone with, much more so than synths for me. I like the way they feedback and shave too. they are a must own imho

 

[stone and strop]

That's almost exactly how I test my edges too! Tree top at 1/2 inch and I'm good to go. Not that I've tested 100's of coticules or anything, but I've never had a coti I couldn't shave off of.



What odds constitute a crap shoot?

I couldn't say.
I have not gone through hundreds.
I do know that finding one that gives extremely keen and smooth edges (comparable to an Escher edge) is by no means common. It is extremely rare.
Most are ok, you can shave off them but are not close enough for most straight shavers and you may have to jump through hoops to get that.
Some are down right awful and the VERY few are exceptional.
I wish mine was larger than 4x2 but it is remarkable in edge quality so I am grateful to have it and be able to enjoy what the best of a stone type can give.