Belgian Yellow Coticule natural water stones

[Tony Shea]

I have been looking around a bit lately for a natural finishing stone to use primarily on my japanese blades (planes and chisels). After reading a recent article by Toshio Odate in a magazine on his sharpening techniques I saw where he mentioned a Belgian Blue Stone. After searching a bit I came across the site The Perfect Edge which carries some stones out of a Belgian Quarry. But the blues do not seem fine enough and went on to read about the Yellow Coticule stones. Just curious if anyone around here has any experience with any of the stones out of that quarry and what kind of characteristics they have.

Some other natural waterstone suggestions would also be very welcome, mostly some finishing/polishing stones that I'd be interested in. The natural waterstone market is loaded with different stones that just boggles my mind and really is a tough place to get started in. With the price of some of these good quality stones I struggle with the notion that the stone I end up picking will not be what I am after. Any literature online on natural stones would also be a huge help.

[James Taglienti]

If you want to learn about fine waterstones try lurking on a straight razor shaving forum (yes they exist, i guess no stranger or draconian hobby than dragging sharp metal blades across pieces of wood as opposed to your face?) I have had dozens of these combination waterstones and the finish seems similar to that which comes off a translucent arkansas, a little foggier but just as sharp i think

[Dale Cruea]

Tony, I have the same problem. Just spend some good money on stones just to find out I don't really like them any better than the others I have tried. I have read that any stone can be used with water as long as it has not been used with anything else.
I am thinking of getting some Arkansas stones and calling it good. I know this did not answer your question but it let me vent. Thanks for listening.:eek: BTW I think stropping works about as well as a polishing stone. Just takes a few minutes longer.

[Jonathan McCullough]

I've found a couple of yellow coticules. They're interesting stones. They make a creamy slurry and contain microscopic garnets or rubies, I can't recall, whose crystal structure makes for a more aggressive cutting surface than most other substances. The substrate is somewhat softer and muddier; you have to be careful or it seems to me that you could gouge the stone more easily than, say, an Arkansas. They make a very keen edge very quickly. Since they're natural, the edge doesn't polish consistently in the same way that a synthetic sharpener would, like my DMTs or ceramics. You wouldn't get a mirror-like sharpness from a coticule, more of a traditional hazy keen-ness. I've been using oil stones more for the simple fact that using water to sharpen my edge tools seems counterintuitive, but if you are a water stone sharpener I think you'd like the yellow coticule.

[george wilson]

Nothing wrong with using water. All the oil or water does is keep the stone from getting packed with crud. I only have used water since the 80's. Water with a little Dawn detergent and a squirt of water based cutting fluid was suggested to me by a famous engraver. I have been using it ever since. My stones stay clean,but I don't use enough water to cause a rusting problem. When I tried some Japanese water stones many years ago,I had a little rust that kept getting onto my tools. Not much,but I didn't want it. At that point,I was using plain water,though. The shop was dry,too.

[David Weaver]

With the price of some of these good quality stones I struggle with the notion that the stone I end up picking will not be what I am after. Any literature online on natural stones would also be a huge help.

Aside from wanting certain edge qualities (like shavers would want) or wanting to use naturals no matter what, you will likely find that there are extremely few stones that will cut as fine as the good very fine synthetics in the $80-$300 range, and there are none that I am aware of that will cut as fast relative to the grit size. If they are truly that fine and that fast, they will cost much more than a synthetic.

The only good and inexpensive natural stones that I'm aware of are arkansas stones.

I don't have any coticules, but I have natural japanese stones as fine as an antique barber hone (finer than any synthetic stone I have, but too slow to use practically for woodworking because of it). I would consider the yellow coticules and thuringians and other such stones to be priced for razor use only. As far as I know, they were both once not that expensive, which leads you to ask the question about why they are so expensive now.

The only other option is a cheap pre-polish japanese stone that you can learn the benefit of different slurry levels and still get a good edge.

But in the end, you'll find that the edge won't be better than a good very fine synthetic stone, it'll likely take longer to get it there, and the virtues that natural stones have with edges (soft feeling for shaving, flat grooves from sharpening, etc) are quickly blasted off by running a tool through hard wood and really of no consequence on the wood to begin with. If I am being honest, every natural stone I have that's large enough for woodworking and less than $300 makes me work to get as good of an edge as I can get from a micron or sub micron synthetic, and none of my natural stones will work across such a wide variety of steels (i.e., get the same sharpness no matter the alloy) as a synthetic, regardless of price.

Most of the stuff that I think I am probably observing with a natural stone, other than the ability to burnish the surface of one to some extent, is probably in my head, and in reality some stone like stu's 13k or a shapton 15k is sharper (and without all of the hocus pocus talk about things unobservable in terms of optics).

[Harvey Pascoe]

I'll second what David Weaver said.

My wife was in Japan last week and picked me up a set of Imanishi Sigma stones and all I can say is wow, are they ever fast, even the 10,000 stone removes metal fast. I particularly like the fact that they are light colored so that you can easily see how much metal is coming off AND when the stone is getting clogged.