Thread: Coticule edges (dilucot) under microscope 160x

Originally Posted by Euclid440

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The quality of the micrographs is also impressive, having been taken with a cell phone.

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Thanks, perhaps my experience out of my previous hobby „photography“ is helpful here

Here is my photo-stream:
Rein -e- Art | Flickr

Regards

Originally Posted by Philipp78

Thank a lot,
happy to read all the positive feedback!

[...]

La Nouvelle Vein was my very first stone for razor honing 2 years ago. Looking back I can say it was a bad Idea to start the sharpening journey with a Coticule. I‘ve spent several weeks scrubbing a hell out of the razor and the stone, wondering why the slurry turns that black but the razor does not reach anywhere near to a shaving condition :S
Purchased several other coties and other hones, selled lots of them again, changed razors and so on... until I‘ve started to change the way I‘m honing

[...]

Les Latneuses I have also purchased in time I could not properly hone, after some tries and errors it has accompanied the La Nouvelle Vein in the shelf. Will involve it back into my team of „active stones“

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Looking forward to learn more about the „yellow mystery“

Regards

Philipp

That sounds about right: initial frustration, wondering why this damn rock won't do what I want it to; leading to slow realisation that maybe, just maybe, I have to suck up my pride and re-evaluate my expectations and approach. Incidentally, my first coticule was a La Veinette.

For learning how to use a particular stone, the recipe seems to be to just focus on one at a time and give it a bit of time. Also, for honing in general, stop before it becomes too frustrating. A challenge is nice, but there's no reason to let honing mess up your mood; this is supposed to be fun, you know.

I've heard La Nouvelle Veine is among the trickier veins to master, which means it might not be the ideal coticule to start learning on. Or maybe it's perfect, giving you a real challenge and making most others seem much easier after mastering it.

So obviously now I want one .

Anyway, good luck with your explorations.

Best regards,

Pieter

Originally Posted by Euclid440

For me, the Coticule edge is just not keen enough for my taste, and that is exactly what many like about the Coticule.

If you find at some point a coticule that has a La Lune backing (I think some sold even with La Lune logo or something, but not all had the La Lune stone back), it might give a keen enough edge. They all seemed to be very hard and fine. Mine is the hardest and finest coticule I have ever found so far. And by far the sharpest coticule edge and a very sharp edge compared to anything, but not aggressive.

I have several natural Coticules and several of the “French” stone, probably some La Lune, though none of mine are labeled.

And yes, they can deliver a keener edge. There is a lot of history written on the French stones here and elsewhere and a lot of mystery about these stones. Seems those that knew the details are gone now.

Euclid440, have you tried to finish with another stone (e.g. the french one) providing the level of keenness your need and then go back to Coticule and do some ultralight strokes.

By this I can reach the HHT5 level on my La Veignette and La Dressante.

To me seems like some cotirs have a quite jump between the coarse „slurry-sharpenong“ and the „poloshing with just the tops of garnets sitting in the stone“.

No, really, I have moved more to Jnats, that provide a keener and smoother edge. I have not experimented with Coticules much, in the last couple years.

Though I buy them when I find them at good prices. I did pick up a couple nice ones recently at an antique flea market.

Perhaps I will dig them out and give them a go. I see Glen did the same.

Originally Posted by Euclid440

Perhaps I will dig them out and give them a go. I see Glen did the same.

That is the true beauty of these threads, I had not touched my BBW since maybe 2010 maybe 2011 that thread made me finish a few razors on it this past week

OK gens,

I had some time and have done some further experiments.
This time the unicot edges.

Before each coti I've kind of "reset" the bevel surface on my recently purchased nakayama kiita (super hard) without a tape.
Kiita is a very fast and very fine stone, so it can easily remove the previous unicot bevel and put a haze finish to the whole surface.
Then applied fresh piece of tape and performed between 50 and 100 strokes depending on the speed and size of the given coti.
For some of coties I've done the procedure under running water to reduce the impact if loose garnets.
Each time i was holding the stone on the fingertips (see: Getting higher HHT of Coticule) to apply a possibly low pressure and to get the finest possible edge.
HHT tests were done using one single long hair for all stones.

For comparison I'll put the dilucot pictures presented at the beginning of this thread.




La Veignette

You see compared to dilucot much higher polishing was achieved at the very edge. The edge has passed HHT4 to HHT5
Seems like despite honed under running water still some single garnets have been released and hit the edge.




La Dressante

Here the same story, very keen edge passing HHT5 (silent slicer).



Next Les Latneuses, hybrid side:

Hybrid Les Lat has produced the finest edge so far also passing HHT5.




Next Les Latneuses, yellow side:

Here seems like the larger/more aggressive garnets have impacted the very apex of the edge (see the white line along the edge).
Still HHT3 to HHT4 was possible with the same hait as tests above.




The unknown shallow grey:

Seems like this hone either does have some single garnets of larger size or it does release some while honing, perhabs next time will try to hone under running water.
Unicot edge has passed HHT4.



La Nouvelle Veine:

Thats definetly the trikiest one. The pressure seems to be the most critical to the results, I needed several attempts to achieve the results displayed above.
But once there a very keen and fine edge has appeared, HHT4+

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On La Nouvelle Veine I've also noticed that the condition of the surface (refreshed vs. already used for a while) can significantly influence the results.
If the surface of the stone was just refreshed (e.g. after lapping of at the end of the dilucot procedure) the unicot provides much coarser edge.
Here a comparison:

After the left picture i've performed around 100 additional strokes which seemed to have conditioned the edge.
Then refreshed the bevel on Nakayama and finished unicot with 50 strokes.

Have also done this "sufrace condition" compare on les Latneuses, hybrid side:

The right picture was taken before, i've just refreshed the coti surface and performed 50 strokes to see the "refresshed" effect.

And also with La Dressante:



Hope those results are as interesting for you as they are to me

Best regards and happy honing!

Philipp

Wow, very interesting results and photos. The white line can be a reflection. I have notices this with very smooth shiny bevels and edges from a CBN edge, where the edge is very thin.

The test show what many have suspected, that edge damage can occur from slurry impact.

I too have suspected that the rough surface from a diamond plate stone can impact the stones ability to polish. I polish my stones with a Tomo Nagura or rubbing stone, after lapping. It seems to produce a smoother surface though, not burnished that reduces cutting ability greatly, just knocks down the rough diamond plate surface, which in turn produces a finer bevel finish.

You may want to try rubbing the stone smooth with a rubbing stone then rinsing off the slurry.

Are your photos pre-stropping? It would be interesting to see the impact of a strop, to see how deep the stria are.

Nice work, thanks for posting.

Thanks for the feedback

Actually the refreshing of the surface in my tests was done by small coticule slurry stone, diamond plate was not involved. The „burnishing“ effect seems to occur after about 100 finishing strokes on the stone. I think that then all the highspot-garnets are broken of/out and the tops of the remaining garnets are kind of burnished to a certain extend.

As per stropping:
Before taking pictures i‘ve run 10 strokes on linen to clean up the apex.
The effect of leather stropping is barrely visible at this magnification (x160)