ShavingUniverse.com

Register a free account now!

If you are registered, you get access to the members only section, can participate in the buy & sell second hand forum and last but not least you can reserve your preferred username before someone else takes it.

Coticule flatness?

horrovac

New Member
Hi people, new coticule and BBW owner here...

I just received my coticule 150x40 select quality from Ardennes Coticule and noticed it is not flat. Approximately one third of the length of the surface dips gradually to a depth of about 1-1.5 mm, more pronounced on one side of the stone. Since I want to use it to hone my razors, this is unsatisfactory. Is this common? Or did I just get a stone that slipped through the QA? Sorry if this question has been answered before, but since I'm currently at work I'm not able to search for a solution at the moment.

Thanks in advance
Horrovac
 
Yes, I'm aware that the coticule is not necessarily of uniform thickness. I was talking about the surface: the surface is not flat, it recedes to a depth of about 1-1.5mm (estimated) over about a third of the length.

Thanks
Horror
 
This is nothing to ruin yor day, my friend.
Ardennes is a small scale production - it's all manual work. They grind the cotis on a large, very coarse carborundum wheel. While the hones should leave production more or less flat they are certainly not tested to be within 0.001 mils of trueness ;)
As said, it's all manual and so there may be one or the other hone that needs some touch up. Personally I would not complain about such a hone, but that is up to you. Generally, Ardennes is very kind and responsive regarding claims. However, I suggest you give your hone some passes on sanding paper to flatten it out.

Cheers
BlueDun
 
Thanks for your encouragement, however it's not just mere mils of deviation, it's 1-1.5mm. Quite easily visible without help from any angle. I have also ordered a BBW (a bit bigger), that I would call reasonably flat. It dips perhaps some tenths of millimetre on the ends, but I'd be quite happy with that. I'd be quite ready to lap it to perfect flatness, that's no problem, but I don't think there's much point in that.

With the coticule however, to get it perfectly flat (which for this hone I find more important, since I'll use it for straight razors) I would have to sand away the said 1 to 1.5mm of material on two thirds of its surface - it would hurt me to do this, since it would be a waste of lot of good hone. I'm not necessarily complaining, I'm aware they're a small business doing a lot by hand, I would just like to know if this is usual with a coticule, or is this perhaps one stone that has slipped through quality assurance.

I've wanted a coticule for a very long time but never came around to buying one. After such a long wait, this does spoil it for me a bit, I'm afraid.

I have now also written to Ardennes to ask them about this. I would still like to know about your experiences though, so I'm thankful for previous and future responses

Thanks
Horrovac
 
Actually, 1.5 mm does seem a tad on the high side. The big rocks are usually checked quickly with a hair lineal which should make such a big offset obvious. So your piece indeed seems like one that has slipped by.
As said, just go ahead and talk to Ardennes. They are really nice folks and I am sure they will take care of you and give their best to make you happy as a customer.

Cheers
BlueDun
 
Welcome on Coticule.be, Horrovac.

Here's a link to our FAQ-article about Coticule flatness:
http://www.coticule.be/faq-reader/items/how-often-do-i-need-to-lap-my-coticule.html.

Ardennes aims to lap them to what they call "a reasonable flatness". I believe they are aware that most buyers will lap their hone a bit further when they receive it. It's something most buyers seem to take for granted when they purchase a Coticule. Some resellers even offer an extra lapping service, either for free or for a small fee.
Personally, I usually don't lap the stones I'm testing for "The Vault", except for the few cases where it really was enough to bother me. In your case I would definitely lap the stone. It's not difficult, but you need to know how to do it. There is an important difference between lapping a hone that became concave (hollow) from use, and one that arrived convex (bulging). I'm assuming that yours is convex. Ardennes' lapping procedure is not the best for dealing with convex surfaces. The problem is that a convex surface can rock on the lapping plate, while a concave surface sits stable from the start.

If you decide to lap your stone, and I think you should, spray glue a piece of waterproof sandpaper on a flat surface. Make sure that the sandpaper is less wide than the length of your Coticule. You need to be able to rub the stone transversally over the sandpaper, without both ends being covered by the paper. If you do it any other way, any rocking motion will cause the far ends of the hone to loose material, which obviously will reinstate the curve rather than removing it. After some transversal lapping, the surface will develop a stable flat area. Once that area covers at least 2/3 of the entire surface, you can continue with longitudinal motions, with the entire surface on the sandpaper. The stone won't rock now, and the far ends will only touch the sandpaper at the very end of the procedure.
I would not bother with lapping the stone all the way. If the last 10mm at either long end are still a bit low, it won't have the slightest effect on the use of the hone.

Kind regards,
Bart.
 
I've had similar experience with my coticules.

They have all for the most part been thicker on one side causing a bit of a slope.

A small adjustment on how I hold it in my hand fixes that problem tho. I wouldn't worry about lapping too much unless the razor is not able to lay flat.
 
Hello again, folks

Sorry I went silent for a while, but I was quite busy... honing.
Yesterday I grew impatient waiting for an answer from Ardennes and ground the coticule flat, then lapped it. I first test-honed my cheapest razor, got a very nice nearly-polished bevel, but it didn't feel very sharp. There ware still some scratches on it, so I'll have to rework it a bit. Today I honed my brand-new extra-hollow ground Dovo, and that went much nicer, though it still didn't feel all that sharp - which I knew is to be expected due to a finer edge, but I wasn't all that sure that it's reasonably good to shave with. So I tested it, and it is extremely good. The results are, in fact, astounding. I had read about the "coticule edge" and was eager to see for myself; I must say it is really something. I had never shaved so close with so little irritation, it is almost as if I hadn't shaved at all. And I'm quite sure I'll be able to get it even sharper after some practice.

Ardennes did respond, by the way, they asked me to send the stone back so they can grind it flat to correct the flaw, which, having already done so myself, I declined.

Anyway, thank you all for your responses and support, it is much appreciated.

Cheers
Horror
 
Back
Top