Thread: Belgian coticule, clarifications

I've been reading the wiki, and some honing threads...is my understanding of the Belgian Yellow Coticule correct?

1. It can set the bevel if used with the slurry.
2. It can then refine the edge with diluted slurry.
3. It can then be used to polish the edge with water only.

In short, it does everything?

I'm sure I've seen a clip somewhere where Lynn hones with a Norton 4K/8K and then finishes with a slurry on a coticule, which contradicts all of the above doesn't it?

It's not really contradictory. In Lynn's video he is using the coticule as a finishing hone. Sort of like your steps 2 and 3 (maybe 2.5 to 3). The Norton 4K/8K pyramid is setting and refining the bevel and the coticule is finishing it and polishing it.

Some guys like to use the coticule to do the whole honing sequence, others use a series of natural or synthetic stones. Its part economics, although I think that is debatable, and part preference and style. To me that's part of the fun of honing.

Hopefully Lynn or some of the other honemeisters will chime in with better detail.

The thing you have to remember about a coticule is that much of the work is done by the honer not the stone... Some of the end result that you get is going to then be dependent on the stone it's self as there are natural variation between stones....

So what you are hearing me elude to is that the stone really does not do any of what you listed

1. It can set the bevel if used with the slurry.
2. It can then refine the edge with diluted slurry.
3. It can then be used to polish the edge with water only.

Your experienced hand with the stone can accomplish that....


Where with the synthetics Naniwa's Shapton's or Norton's the stone does most of the work, your part consists mostly of moving the razor smoothly and evenly down the stone....

I have several different types of hones. 99% of the time I just use the coticule. I slide the razor back and forth on it and then I shave. That's pretty much it for me.

Originally Posted by jcd

I've been reading the wiki, and some honing threads...is my understanding of the Belgian Yellow Coticule correct?

1. It can set the bevel if used with the slurry.
2. It can then refine the edge with diluted slurry.
3. It can then be used to polish the edge with water only.

In short, it does everything?

Yes it does.

There are variations in Coticules, since they are a natural product. Those variations are mainly in speed while honing on slurry. But still, the majority of Coticules are fully capable of doing all the work required, as long as we're talking about undamaged razors (this means: no flaws such as heavy corrosion or missing chips, that could easily be spotted with the naked eye).

Setting a bevel on a Coticule with slurry is easy. I may take some patience, depending on the condition of the razor, but there really is nothing enigmatic about it.
The second goal, getting the razor as keen as possible, is the hardest part. I requires a good honing stroke. I'm currently testing a very simple trick to make this easier, and planned on posting about that in the coming week. Still need to repete the success of it on a few more razors and a few more Coticules, before I can start recommending it.
The final goal, finishing on water, is as easy as the first goal. It doesn't even require patience, nor special honing skills.

Honing on Coticules may not be the fastest method, but I do the majority of my honing on them, and I'm not getting complaints.

Best regards,
Bart.

I think a great way of understanding why a coticule is special is to look at the pictures here. The Coticule - With Slurry bevel looks like it has been sand-blasted rather than honed. It is due to the abrasion being done by "football-like" garnets in the slurry rolling about and digging out metal when the corners hit the bevel.

Originally Posted by Rajagra

"football-like" garnets

"Football-like" (rhombic dodecahedron) garnets are in the Belgian Blue Stone!

In the (Yellow) Coticule the garnet-crystals are crumbled and more polymorphic. That’s also the reason why the blue and the yellow stone differ in grit:

Belgian Blue Stone is a 5000 - 6000 grit and the
Yellow Coticule is an 6000 - 8000 grit.

I used to use a Coticule with a light slurry for polishing an edge before pasting. It worked for a long time. Then I found that water alone actually worked better.

A Coticule can be used to do all the things you asked about although it takes a significant amount of time when compared to using other stones which is why I prefer the other stones. There is also a matter of consistency in using the Coticule when it comes to results. Yes you can accomplish the task on one razor, but the time, number of strokes, etc, may be different on the next razor.

Lynn

Originally Posted by Carioca

"Football-like" (rhombic dodecahedron) garnets are in the Belgian Blue Stone!

In the (Yellow) Coticule the garnet-crystals are crumbled and more polymorphic. That’s also the reason why the blue and the yellow stone differ in grit:

Belgian Blue Stone is a 5000 - 6000 grit and the
Yellow Coticule is an 6000 - 8000 grit.

I was under the impression that the Belgian Blue and the Coticule differed in the concentration of the garnets rather than their shape. Don't the garnets change shape as they are cleaved during honing?

Originally Posted by Bill S

I was under the impression that the Belgian Blue and the Coticule differed in the concentration of the garnets rather than their shape. Don't the garnets change shape as they are cleaved during honing?

I don't believe we can cleave the micro-crystalline garnets while honing.

And you are right the Yellow Coticule has 35% - 43% garnets,
the Belgian Blue has 30 % garnets.

But the important difference is garnets shape:
Yellow Coticule is more abrasive, it’s a better sharpening stone...
the Belgian Blue more a polishing stone.