The Coticule of the Ardenne

[ernest dubois]

379725
A laminated with off-cut for making slurry and a shard I picked out of tailings at the side of the mine. I always collect these for gouges, small edges etc....
The stone from the original vein was better quality, a bit harder. One in the second-hand shop I had I've given away now.

[Philipp Jaindl]

As has already been said a bit Off-Topic in Brians chisel thread, they are fantastic stones, though Prices nowadays are sometimes just ludicrous for the yellow ones at least.

How long does yours last untill you need to flatten it again? in my experience some Steels and very narrow tools "dent" it faster then id like.

Also do you have any experience with the Blue ones? they are available in good size Stones for agreeable prices, never used one myself though.

[Lasse Hilbrandt]

379727
379728

This stone is not laminated as a coticule usually is. What you see is both sides of the stone. Im not sure, but I think its a Belgian Coticule, but its a bit confusing since its not laminated. It belongs to a friend of mine.

[Patrick Chase]

A laminated with off-cut for making slurry and a shard I picked out of tailings at the side of the mine. I always collect these for gouges, small edges etc....
The stone from the original vein was better quality, a bit harder. One in the second-hand shop I had I've given away now.

Do you know which vein yours came from? I've always been curious to try a good La Veinette stone, but they're astronomically expensive and I'm not that dedicated.

[ernest dubois]

How long between flattening? A long time. But this is more to do with my economy with these stones. As I put it before, on odd shaped edges I turn to small shards which I have given a flat surface so I can economize on the bench stones.
379729Two of the purple sit on the workbench. They are markedly slower cutting. The bench sized stone was between 25 & 30 €, the other one I use as my axe stone also a reasonable price, no need to be particularly economizing with these. I like the smell they give in use.

[ernest dubois]

It's a coticule, I'm almost certain, a bit of the hard stone is embedded. Does your friend flush it with petroleum? I have had one almost the same though less fissured, also solid but then the stones out of the original vein were somewhat harder. These are the highly coveted versions. Mine I gave away.

379727
379728

This stone is not laminated as a coticule usually is. What you see is both sides of the stone. Im not sure, but I think its a Belgian Coticule, but its a bit confusing since its not laminated. It belongs to a friend of mine.

[Lasse Hilbrandt]

Ernest, My friend has´nt used it yet. He recently found in the basement of a house he just bought. It was in a box with some old wooden hand planes. How does he find out if petroleum has been used with it and is it important ?

[ernest dubois]

It's known that some users will flush with machine oil or diesel, or something like it but, the convention is definitely using water with these stones. The one I know that uses oil claims it reduces wear and hardens the stone. It should be obvious with the stone in hand whether oil has been used by feel or smell and when that is the case it should continue to be used. I only mentioned it because the thought struck me looking at the photo. With water it's not my experience that filings accumulate in the fissures with oil I can imagine that they would and cause this accentuation we can see.

On the question of the specific geological origins of my stones, it would take far more competence in the French language than I possess to get that information out of the people I bought it from. It's a way of saying, I don't know which vein, but think it was a good one.

[John C Cox]

Interesting world we live in.... The fact that I have never heard of Belgian or French coticule prior to this.. And i have never seen anything else in real life besides Japanese stuff, Arkansas, India, and sandpaper.....

But yet everybody in the world has been woodworking for a very long time... And they must have sharpened on something.....

[Lasse Hilbrandt]

Interesting world we live in.... The fact that I have never heard of Belgian or French coticule prior to this.. And i have never seen anything else in real life besides Japanese stuff, Arkansas, India, and sandpaper.....

But yet everybody in the world has been woodworking for a very long time... And they must have sharpened on something.....


In the Scandinavia we used slate until Belgian Coticule and even later Arkansas and India became awaileble.

[Patrick Chase]

In the Scandinavia we used slate until Belgian Coticule and even later Arkansas and India became available.

SNat!

You probably know this, but the Belgian blue stone that backs non-laminated coticules is a slate.

India stones don't really count IMO, since those are just Alumina and a binder, like a synthetic waterstone.

[ernest dubois]

Many stones existing outside the parameters of the Angelo/English experience, (the Japanese stones having recently gotten drawn in). A nice stone coming out of the Pyrenees is one similar to the dark Arkansas and still queried, popular and readily available in France. The Orsasten near the known edge tool producing area of Mora and Eskultuna in Sweden for example. Still, I believe that coticule is regarded as the best of these by some.

[Patrick Chase]

Many stones existing outside the parameters of the Angelo/English experience, (the Japanese stones having recently gotten drawn in). A nice stone coming out of the Pyrenees is one similar to the dark Arkansas and still queried, popular and readily available in France. The Orsasten near the known edge tool producing area of Mora and Eskultuna in Sweden for example. Still, I believe that coticule is regarded as the best of these by some.

I've come to believe that the best is usually whatever the speaker has learned how to use most effectively (where that learning often includes things like tool/steel selection). IMO that has a lot to do with why sharpening is such a contentious topic.

I also think that it's safe to say that some media are more "accessible" than others, with coticules probably being more on the skill-intensive end of the spectrum. I wouldn't recommend them to somebody who just wants a "good enough" edge in a hurry.

[John C Cox]

I wouldn't recommend them to somebody who just wants a "good enough" edge in a hurry.

Yeah... The power belt sander sucked all the wind out of the "good enough quick" Sharpening Universe didn't it...

I guess it just surprises me that Japanese water stones are all the rage - and yet there is an almost completely unknown (in The States) European equivalent that's been around for just as long - maybe longer... Reinventing hot water I suppose...

[Patrick Chase]

Yeah... The power belt sander sucked all the wind out of the "good enough quick" Sharpening Universe didn't it...

Depends on your definition of "good enough". Trizact belts top out at 6 um (~2000#, or 2500# if you're rating "a la Shapton"). There's a huge gap between that and what the razor types wring out of their coticules. Well-lapped Arks, synthetic waterstones, Spydercos, etc all inhabit that gap, which IMO is a reasonable place to strive towards for woodworking.

As an aside, Coticules are also ~6 um, but you can't really rely on particle size when comparing a super-aggressive geometry like the "Trizact pyramid (http://www.leevalley.com/us/wood/page.aspx?p=66268&cat=1,43072,75712)" to something like dodecahedral garnet particles as in Coticules. The latter seem to be comparable to micron or sub-micron Alumina.



I guess it just surprises me that Japanese water stones are all the rage - and yet there is an almost completely unknown (in The States) European equivalent that's been around for just as long - maybe longer... Reinventing hot water I suppose...

"Completely unknown" is a bit strong. The straight razor crowd have all been aware of Coticules for a long time. I'm not into that but I know a bit (rough history, the major veins/types, etc) from osmosis.

Part of it is that Coticules are regarded as providing a very "soft but sharp" edge, which is highly desirable for shaving but not as prized in WWing. See the last couple shots here (https://scienceofsharp.wordpress.com/2015/03/24/sharp-and-keen-part-2/) and note the "micro-dubbing" of the blade tip. If your only exposure to this stuff is from our community then it's understandable that you'd be more attuned to Japanese-style waterstones.

[Mike Baker 2]

As someone who hones straights regularly, I can tell you a coticule gives a lovely edge. They get sharp, but it is a face friendly kind of sharp, where something like a synthetic water stone, and even some Jnats, can get too sharp for some people's faces. And then there's lapping film. That right there is SHARP!
I regularly hone with a coticule of unknown vein, a shobudani Jnat, vintage Escher, synthetic stones and film, and Arkansas stones. You can get a beautiful shave from all of them, but if I had to pick, it would be a coti or my Escher. But since different people like different edges, I keep myself familiar with all of them.
IMO Coticules are beautiful stones, and I would not hesitate to use one as a finish stone in a progression for woodworking tools.
Unfortunately for me, my coti is for straights only, and won't be used for anything else. There are more mundane things, like diamond or synthetic water stones, to hone chisels and plane irons on.
Or a beautiful old Arkansas.

[ernest dubois]

It is curious, the Flemish name of these stones is Belgische Brok translating to something like Belgian Chunk which would imply something other than what might be thought of as a bench stone and more along the lines of the piece that Lasse has loaded on, a form seeming particularly suited to taking in hand for honing a straight-edge razor and not woodworking tools. Still, older stones in the bench stone format do exist, it's just that label that raises certain pertinent and interesting questions.

[Mike Baker 2]

Well, they were used all over Europe and in the U.S. as straight razor hones, by individuals and by barbers. I have seen old barber handbooks from here in the U.S., and they were the coveted and preferred hone for razors for a long time.
But I'd be willing to bet, like the Black Arkansas my Father in Law used to hone both his straight and his tools, and the knife in his pocket, that they did double duty when it came time to sharpen pretty much anything.
And they are a chunk of rock, in reality. Pretty much any natural stone meets that descriptor. Somebody had to carve it, chip it, saw it, into that square shape if they wanted it that way, so I would not personally put too much emphasis on the work "chunk" as a descriptor of what it was used for. YMMV.
Besides, shape is not so important;as long as you can get it to lay flat and still, you could hone plane irons and chisels on it just fine.
If you actually go to the Ardennes sight, one of the first things you have to do to find the stone you want is to specify whether you are looking for a stone for razors, knives, or tools. They are different, and not every coticule out there will be appropriate for straight razor use. They are natural stones, and each individual one will be slightly different. So much so, in fact, that for honing straights you have to "learn" the stone you are using. Most of them take slight variations in your technique to drag their best edge out of them.
Lovely stones, and I agree, the history of them is fascinating and fun.

[ernest dubois]

Well, what about this - and for the moment anyway leaving aside all uses involving the barber - that the bench format is a deviation, or is a indication of a shift in sharpening technique. That as you say it, the chunk is useful on plane blades and so possibly indicative of a primal technique used to sharpen a range of woodworking tools. After all I was instructed by one teacher while attending furniture making school those years back in Amsterdam, to do just that, take the stone to the tool and not the tool to the stone. Of course I scoffed at the idea then and maybe less so now.

Except when I go to the Ardenne for a stone I just jump down in the river there and pluck the nice looking ones off the bottom.

[Mike Baker 2]

I could see that. I think the stones themselves tend to influence technique a bit. But remember, there are many different techniques for sharpening in use today; just start a sharpening thread and watch the contention there. As we discover different or new(or new to us) techniques, the older stuff isn't entirely abandoned.
Probably the oldest technique is "taking the stone to the tool". An axe, for instance. Even now, I would bet if a stone is used, that technique is employed a lot. I know it is what I do.
But as pertains to wood working tools, I think people just did what worked for them, just like we do now.
As a free hand sharpener, I take the tool to the stone because IME it is easier to maintain the bevel correctly, but again, that's my experience. We all do what works for us.
If you like looking into the history of honing, stones, etc., there are a lot of guys on the internet who are doing the same thing, and there is tons of information out there, if you are willing to dig for it.
I have a friend who is fascinated about every minutia he can find on this subject. The knowledge is there, and he's digging. And finding a ton on it.
The biggest thing I think about these stones, or even the Arkansas stones our grandfathers used before us here in the states, is the rich history that comes with them. Very cool.
And by the way, I know you said leaving out barber use, but when I hone on a coticule, mine is hand held.

[ernest dubois]

And sometimes the axe is taken to its "stone"
https://vimeo.com/207995022<a href="https://vimeo.com/207995022" target="_blank">
&lt;iframe src="https://player.vimeo.com/video/206737956" width="640" height="360" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen&gt;&lt;/iframe&gt; &lt;p&gt;&lt;a href="https://vimeo.com/206737956"&gt;BROADAXE CONDITON&lt;/a&gt; from &lt;a href="https://vimeo.com/user11122485"&gt;Ernest DuBois&lt;/a&gt; on &lt;a href="https://vimeo.com"&gt;Vimeo&lt;/a&gt;.&lt;/p&gt; (https://vimeo.com/207995022)

https://vimeo.com/206737956

I don't see much written about different techniques, really different that is to say. Always the assumption seems to be variations on standing, sitting or kneeling before your rectangular shaped stone going at in back and forth.

[John C Cox]

I think as a practical matter on old tools (and probably new ones too..) - taking the stone to the tool probably makes the most sense in the context of using the actual tools at hand. This allows for the tool telling you what it wants as a result of variable carbon content and heat treatment driving varying edge geometry.. And once you sort that out - you would rather not plow that same ground anew every time you sharpen... Just match whatever is already there (assuming it's already working right) and you are probably OK.... Within this context - free hand sharpening rules the day.. The edge geometry ends up all over the map - but your tools work fine on the wood..

What I am doing now (that's honestly not working particularly well on the wood) is using a fixed sharpening routine and trying to find the tools which work with that... In theory - it's probably great once you get there (where ever "that" is ;) ;) )... But I am not there yet..

[ernest dubois]

I think as a practical matter on old tools (and probably new ones too..) - taking the stone to the tool probably makes the most sense in the context of using the actual tools at hand. This allows for the tool telling you what it wants as a result of variable carbon content and heat treatment driving varying edge geometry.. And once you sort that out - you would rather not plow that same ground anew every time you sharpen... Just match whatever is already there (assuming it's already working right) and you are probably OK.... Within this context - free hand sharpening rules the day.. The edge geometry ends up all over the map - but your tools work fine on the wood..

What I am doing now (that's honestly not working particularly well on the wood) is using a fixed sharpening routine and trying to find the tools which work with that... In theory - it's probably great once you get there (where ever "that" is ;) ;) )... But I am not there yet..

I have a feeling that in the museums and books a lot of what we are shown and have seen and think of as really good woodworking was accomplished like this.

[Warren West]

I bought a nice La Vienette from Maurice a couple years back. It was specifically for sharpening carving tools. I sharpen by hand and can sharpen on sandpaper, oil stones, water stones, diamond ceramic, etc. I like coticule but I tried all amounts of water/slurry and I could not get an edge that was as good as I can get from Arkansas or ceramic stones.

I could get an edge on one of the other stones, take it to the coticule and it never improved the edge, but made it worse. Conversely I could go from the coticule to any arkansas or spyderco and get and improved edge. I'm thinking I was experiencing slurry dulling, except I even tried with just water and no more than a few strokes, wipe the stone and add more water, never letting the water become cloudy in the slightest. I was dissapointed in the stone and felt like it should do better than that. I felt a little like there was something I was missing, but I read enough coticule sharpening techniques and tried them all.

These are the orginal splash and go stone.

Sold it to a razor sharpener that loves it.

[Patrick Chase]

I bought a nice La Vienette from Maurice a couple years back. It was specifically for sharpening carving tools. I sharpen by hand and can sharpen on sandpaper, oil stones, water stones, diamond ceramic, etc. I like coticule but I tried all amounts of water/slurry and I could not get an edge that was as good as I can get from Arkansas or ceramic stones.

Define "good". Hint: It's subjective and depends on what you're doing.

In my experience people who like Coticules tend to prefer "soft but sharp" edges, such as might be desirable to avoid irritating the skin with a straight razor. As a woodworker I prefer a "harder" edge with crisp geometry, and so I don't use Coticules. Based on your stated preference for Alumina stones in the other thread (basically the harshest of the traditional abrasives) I suspect you have similar subjective preferences.

That doesn't mean that Coticules leave a "bad" edge, though, but rather that they create an edge that doesn't jibe with my (or apparently your) preferences and objectives.

Also Coticules take a LOT of practice. You don't so much "try" sharpening techniques as "live" them. I know people who've spent years figuring out how to get the most out of a single stone, particularly when they start getting clever with "dilucot" and the like.

[Warren West]

Define "good". Hint: It's subjective and depends on what you're doing.



Agreed. I said I was sharpening carving tools Good relates to that and should not be extrapolated to meat cleavers, sushi knives, razors or lawn more blades. For my needs the edge off the coticule is not as good as many other sharpening mediums.

I was disappointed in the coticule as it pertained to my needs. That same stone did work well for someone else's purpose.

[ernest dubois]

I was disappointed in the coticule as it pertained to my needs. That same stone did work well for someone else's purpose.

Yes, many generations of woodworkers, and even Patrick Damiaens (https://discoveringbelgium.files.wordpress.com/2014/11/kopie-van-_phd2102.jpg) I see uses one.

[Warren West]

Yes, many generations of woodworkers, and even Patrick Damiaens (https://discoveringbelgium.files.wordpress.com/2014/11/kopie-van-_phd2102.jpg) I see uses one.

I read an article where he mentioned coticule for sharpening. From the photo it looks like he uses a powered buffer too, perhaps the Koch or similar.

[Christian Setla]

Gents,

Please remember, coticule hones have been used for a long time, high carbon steel has also been used for a long time and the two work very well together. Modern PM11 or A2 and the like, will not work well with a coticule. Why, you ask? The coticule contains garnets as the abrasive element. Today, garnets are used in the cheapest sandpaper you can buy.... because they don't last. Garnets, with their wonderful dodecahedron shape, do wonders smoothing a high carbon steel (think vintage Sheffield straight razors from the 1800s), but are sadly lacking when it comes to todays modern hard tool steels.

Slurry vs non slurry. Raising a slurry allows a coticule stone to cut faster (in fact, you are lapping, not grinding, as the garnets have been released from the hones surface). Garnets still fixed in the surface will tend to burnish more than cut, which is what modern fractured (like a glass shards) abrasives, fixed in a binder, hones do. This is the reason many find that a coticule does not perform well after flattening the hone with a diamond plate... The diamonds will fracture the garnet crystals and thus prevent the burnishing effect that straight razor shavers know as the "smooth edge" of a coticule honed razor.

As wood doesn't give a flying fig about smoothness (unlike my face whilst shaving with a straight razor), I will resort to a modern hone using modern abrasives for all tool steels, be it high carbon (old school) or the new steels.

Coticules vary in softness and amount of garnets AND size of said garnets. Some hones will "auto slurry" by simply attempting to hone a blade... others are rock hard and resist such slurry activity, requiring the use of a slurry stone (a piece of coticule... NOT a diamond hone that would fracture the garnets). 15 years ago, nothing was said about what "vein" a hone came from... then the elitists (my opinion) began making a big deal of which vein a hone came from. My opinion, spend some time with the hone.... if it just doesn't work for you, flog it off to someone else... but don't be surprised if they claim it's the greatest hone ever! They just "figured" the hone out, and you could have too if you gave it a chance.

In woodworking, it seems to me that getting on with the woodworking is more important that honing tools.... When it comes to shaving my face... I'll spend some extra time on the edge to make sure it's smooth and comfortable while shaving.

Bottom line, I'll reach for the Shapton or Naniwa synthetic hones (16K and 12K, but due to the manufactures fudging, I find them equivalent), and for my Shefield made straight razors from the 19th century, I'll go for either the Coticule or my Zulu Grey as a finisher, but the preliminary honing is still done on synthetic hones from (in my case) Naniwa.

Regards

Christian aka

Kaptain "I used to have HAD (hone acquisition disorder, but now I don't) Zero

[ernest dubois]

Gents,

Please remember, coticule hones have been used for a long time, high carbon steel has also been used for a long time and the two work very well together. Modern PM11 or A2 and the like, will not work well with a coticule. Why, you ask? The coticule contains garnets as the abrasive element. Today, garnets are used in the cheapest sandpaper you can buy.... because they don't last. Garnets, with their wonderful dodecahedron shape, do wonders smoothing a high carbon steel (think vintage Sheffield straight razors from the 1800s), but are sadly lacking when it comes to todays modern hard tool steels.

Slurry vs non slurry. Raising a slurry allows a coticule stone to cut faster (in fact, you are lapping, not grinding, as the garnets have been released from the hones surface). Garnets still fixed in the surface will tend to burnish more than cut, which is what modern fractured (like a glass shards) abrasives, fixed in a binder, hones do. This is the reason many find that a coticule does not perform well after flattening the hone with a diamond plate... The diamonds will fracture the garnet crystals and thus prevent the burnishing effect that straight razor shavers know as the "smooth edge" of a coticule honed razor.

As wood doesn't give a flying fig about smoothness (unlike my face whilst shaving with a straight razor), I will resort to a modern hone using modern abrasives for all tool steels, be it high carbon (old school) or the new steels.

Coticules vary in softness and amount of garnets AND size of said garnets. Some hones will "auto slurry" by simply attempting to hone a blade... others are rock hard and resist such slurry activity, requiring the use of a slurry stone (a piece of coticule... NOT a diamond hone that would fracture the garnets). 15 years ago, nothing was said about what "vein" a hone came from... then the elitists (my opinion) began making a big deal of which vein a hone came from. My opinion, spend some time with the hone.... if it just doesn't work for you, flog it off to someone else... but don't be surprised if they claim it's the greatest hone ever! They just "figured" the hone out, and you could have too if you gave it a chance.

In woodworking, it seems to me that getting on with the woodworking is more important that honing tools.... When it comes to shaving my face... I'll spend some extra time on the edge to make sure it's smooth and comfortable while shaving.

Bottom line, I'll reach for the Shapton or Naniwa synthetic hones (16K and 12K, but due to the manufactures fudging, I find them equivalent), and for my Shefield made straight razors from the 19th century, I'll go for either the Coticule or my Zulu Grey as a finisher, but the preliminary honing is still done on synthetic hones from (in my case) Naniwa.

Regards

Christian aka

Kaptain "I used to have HAD (hone acquisition disorder, but now I don't) Zero
I have noticed obvious variations especially in the coticule out of my informal collection - the ones picked from the tailings at the mine - which is to be expected since they have not been through a very rigorous selection, ( what a lot of the people here might call the ol' QC). Well, it just shows, the stone you use should be the appropriate one.

I bet Damiaens does use a buffer. Peter took me by his workshop one evening so many years back now, though Patrick wasn't in, and I don't remember the scene too well but Peter himself relied heavily on buffing out and they were at school together so I guess that comes from there.