Thread: Assess coticule quality?

Assessing a honing job is a matter of eliminating a number of variables. First, is your coticule flat? If it's not, that's the first variable to eliminate. Second, are you using magnification so you can see the edge before treatment and then after treatment? That's the sure way to know what you're doing and what effect you're having on the edge. The coticules do come in 2 grades from the quarry in Belgium. The euro grade and the Select grade. I only sell the Select grade and they're pretty uniform! There is always variation in natural stones but the difference in final shave is more likely to be from other factors. Keep at it. For hundreds of years barbers used a coticule and a natural leather strop and you're likely to get good results if you can see exactly what you're doing. The HHT is a very subjective test and many have come to the conclusion that the only real test of an edge is whether or not it shaves your face.

Thanks for the input gents!

First, I will collect the material necessary to lap the coticule as described by Josh Earl... once that job is done, I will give the honing another try... actually, my coticule looks like it is flat, but that might not be the case.

@Bart: I will keep you posted on the progression and maybe I do need another cotigura... my rubbing stone is quite large (about 1.5cm by 5cm), is it possible I do not put enough pressure on it to generate thicker slurry? Anyway, I will put a picture of the coticule online as soon as I have the time to take some pictures

@Howard: I bought my coticule here in a shop in Belgium and I have no idea what quality grading it got.

Best regards!

There's only one coticule quarry left, and each new coticule that's sold comes out of that quarry. They have a website: Ardennes Coticule - pierres à aiguiser et moellons de Vielsalm Belgique.
They actually produce coticules in four different grades: third grade (mainly sold for industrial use), standard grade, select grade and kosher (very rare). The first three are basicly all the same stones, with more, or less cosmetical flaws. Absolutely flawless and uniform in color is sold as "Kosher". The current grading system has nothing to do with the hone's capabilities, but I don't think that Maurice and Rob Celis allow coticules with serious defects to leave their firm.
I only noticed a minute ago that you're a fellow countryman, Tim.
What's you location? I'm from Heist-op-den-Berg. Together with two other straight shaving guys we're having a cozy shaving night every 6 weeks or so. We send off the wifes to the pub and hone razors, smoke cigars, and drink whisky while talking about genuine guys stuff. You 'd be more than welcome to bring your coticule and razors.

Good luck,
Bart.

Hi Bart,

We 're fellow countrymen, indeed! I'm living in Dendermonde, so that's not too far away from Heist-op-den-berg! It'd be great to attend one of the shaving nights and get to know other straight razor shavers... I don't smoke cigars, but wouldn't say no to a glass of whisky

BTW, at present I don't feel like I've received a bad coticule or so... Probably it's just me who's doing something wrong... Tomorrow, I'll fetch the sanding paper and give the lapping a try. I started this thread to find out if it's possible to see the difference between a "good" and "bad" coticule in some way, for example through a microscope or so... As the honing results are not there yet, I might eventually feel the urge to buy a "kosher" coticule though... it's starting to itch

Thanks for the invitation!

Tim

Hi all and especially to Bart.
I read often that a str8 razor is getting sharp when it start to "undercut" the slurry instead of pushing the slurry forth with the bevel.
Is this real a sign of sharpness, or is it only some kind of urban legend?
My coticule never undercuts the slurry, but I do get excellent bevels.

Best regards

Originally Posted by kingreverent

Hi all and especially to Bart.
I read often that a str8 razor is getting sharp when it start to "undercut" the slurry instead of pushing the slurry forth with the bevel.
Is this real a sign of sharpness, or is it only some kind of urban legend?
My coticule never undercuts the slurry, but I do get excellent bevels.

Best regards

As a matter of fact, I always pay a lot of attention to what the fluid on the hone does during the passage of the razor. In my opinion, that's all part of what is often called "feedback" of a particular hone: all things that can be felt, heard or seen while honing.

Whether water or slurry runs up the razor, depends on a few variables, and I wouldn't consider water or slurry running up the razor a sign of keenness, but it does tell me certain things about my stroke. For instance: if you hone a smiling edge, and you don't do anything specific to improve contact with the heel and toe of the razor, the result will be a razor with a sharp middle part and a dull toe and heel. For tackling that problem the "rolling X-stroke" allows for better contact with the hone along the entire edge. But how much "rolling" does one needs to apply to his stroke? The answer is: watch the water (or slurry) run up the blade. Set your mind at making the water run up the heel section first, then up the middle section, and finally at the end of the stroke, up the toe. Focus on that, watch the water (slurry) and your arm will make it happen almost automatically.

The same thing works equally with slightly warped razors. Watch the fluid and it 'll tell you where and how to fumble with your stroke to maintain contact with all parts of such a blade.

As for sharpness: if you take a blade with a serious roundness to its bevel, such as many old razors coming from Ebay or an edge stropped to oblivion by ignorant hands, that blade will tend to push a wave of fluid in front of the edge without it running up the bevel. That effect is most apparent when the layer of fluid is thin and the blade is still dry. As soon as the blade becomes wet, the water will run up more easily, due to cohesive forces in the water molecules. But if you observe real close how the water searches the easiest way to run up the bevel you 'll now where that bevel is starting to develop and which part is staying behind. I'm not saying that I'm relying on that alone, while honing, but it does often tell me when not to bother with a TPT just yet, but keep on going a bit further.

On a coticule with slurry, I have witnessed many times how the slurry runs up the bevel very well during the first few laps and then starts to be more pushed in front. That's because the use of slurry on a coticule has some abrasive effect on the bevel tip of the edge. The garnets are removing metal from the sides of the bevel quickly, but they also meet with the tip. That's why you always should finish on a coticule with water only. That way the garnets stay embedded in the surface and while the coticule cut much slower in that fashion, the abrasive effect on the bevel tip is prohibited. I generally hone during my finishing stage on the coticule with water till I see a clear improvement of the water running up the bevel again. Then I perform a final TPT, and if everything checks out, I move to the strop and test shave.

As to razors "undercutting" the slurry, I think it depends a bit on your definiton of that verb. Sure, an edge will always push a fluid forth, but an amount of it will run up that bevel, and there is some relation between the width of the tip and the amount of fluid running up. Learning how to read that, takes experience, and I believe you could easily do without that skill, if you chose to. Some people have stated they can feel it in the way a razor rides the hone, when it is sharp. I personally am not blessed with such "fingerspitzengefuhl", as the Germans say, but what works for someone might not work for another, and vice versa.

I hope this answers your question,

Regards,

Bart.

Originally Posted by Tim

Hi Bart,

We 're fellow countrymen, indeed! I'm living in Dendermonde, so that's not too far away from Heist-op-den-berg! It'd be great to attend one of the shaving nights and get to know other straight razor shavers... I don't smoke cigars, but wouldn't say no to a glass of whisky

BTW, at present I don't feel like I've received a bad coticule or so... Probably it's just me who's doing something wrong... Tomorrow, I'll fetch the sanding paper and give the lapping a try. I started this thread to find out if it's possible to see the difference between a "good" and "bad" coticule in some way, for example through a microscope or so... As the honing results are not there yet, I might eventually feel the urge to buy a "kosher" coticule though... it's starting to itch

Thanks for the invitation!

Tim

As far as I'm aware of, quality differences between coticules are not readily to be seen under a microscope. I'll keep you posted when our next shaving night is due. You can bring your coticule, and be able to compare it's honing behavior with more other coticules than you ever wanted.
Cigar smoking is recommended, but not required.

Hartelijke groeten,

Bart.

Tim,
If you bought the coticule in Belgium, you may have gotten the euro grade of stone. I heard from one SRP member that they carry that grade in the shaving shop in Antwerp. I mailed him a Select grade coticule (how about THAT! shipping coticules BACK to Belgium! Strange but true) and he sent me an exclamatory email praising the stone. The slurry you describe as the consistency of milk is exactly what you should be using to hone your razor. The Belgians call it an "abrasive milk". If it gets too thick, just spritz some water on it to make it more milky.

As planned, this weekend I collected sanding paper (320 and 800 grit) and flattened the coticule (for the first time)... Thanks to the hone lapping 101 this was an effortless job! After lapping, the difference was clearly noticable on the hone...

So far for the good news... I started with a "milky" slurry (I cannot produce thicker slurry) and gradually added more water to end up with only water after about 70 laps... Then I did about 15 laps on the coticule with water only to finish on the strop... result: I (further) dulled my TI's edge
Only after 30-40 extra laps on the coticule with water the razor started to split (note: NOT pop) hairs again when trying the HHT... but the shave still felt rough I really don't know what's going wrong, I really try to minimize pressure to the absolute minimum on every (X pattern) stroke... sigh
On the positive side, the razor splitted hairs over the entire edge now, probably due to the flattened hone... I did not mention it before, but it originally only splitted hairs at the toe and the tip...

@Howard: yes, I bought my stone in Antwerp about 2 years ago, maybe there was no grading system at that time, I don't know... until recently, the TI was my only razor and I was afraid to ruin it while honing, that's why it took so long for me to really start honing. In the meantime, I went back to the shop to get it honed (coticule + pasted strop) and bought the Dovo from Lynn... Conclusion: 2+ years of shaving and stropping experience, but little experience in honing.

Tim

Tim: keeping pressure to a minimum is good at the end of a honing cycle but in the beginning, you want to have a little pressure on it--as Howard will tell you, you are grinding steel. You need some pressure. Towards the end, lightening up is a good idea. Another feedback cue to watch for on Belgians: when the edge is getting close, you will start to feel a kind of "pulling" or "skipping", almost as if the blade is trying to cut into the stone but can't. Right about then is when I start to back off on pressure. Also, just to echo what others have said, don't worry about overhoning; you won't create a wire edge on a Belgian. The only thing you'll do is remove more metal than necessary--the edge will reach a certain sharpness level and stay there.

Also, did you already have a sharp bevel (Good TPT) before you started on the coticule? It could take a while to hone up (several hundred strokes--remember, you won't overhone-- if you didn't. If your razor has a double bevel to remove, you're going to need a coarser stone first.

Let us know how it goes.