coticule concerns

Hi All,

So I've been using a coticule for some time now (not really, about 6 months) and I'm concerned with wearing the stone away with all the lapping I do, and will do on it. When I first got it, it was so misused and worn in the middle so bad that I had to put it on a bench sander for a bit to get a flat surface to lap on. I'd say I have 1/4 in of coticule left stuck to black schist.

My question is this: has anybody, at the rate of honing maybe 10 razors per month (starting off a 4k stone) worn a coticule down enough that it was unusable? At this rate, how long should I expect this stone to last?

thanks,

Dave

There are soft coticules however most are pretty darn hard. I have mine a few years and use it all the time and there isn't a trace of wear on it.

Are you using it to set bevels and such, or just as a finisher?

Usually coticules are fairly hard and don't require frequent lapping at all. You may be surprised, it may not be wearing down as much as you think. I've had mine for nearly 3 years and it has yet to see a lapping stone (came prelapped when I bought it).

are you lapping it? and with what?

I think you are a little paranoid. Honing razors off a 4k will require a slurry as you may be aware, which helps to keep the surface flat. Honing 10 a month = 120 a year. I wouldn't think that would wear it down for a good number of years, however if you wanted to reduce wear, I'd recommend you got an 8k to go to after 4k and then finish on the coticule with plain water after the 8k.

Using an 8k after 4k as opposed to coticule and slurry, should only require 20-30 laps and then anywhere from 30-60 laps using plain water on the coticule, potentially starting with a very light slurry on the coticule for the first 10-20 laps.

I don't think you have to worry about this. If you use it with thick mud like slurry, that's another matter. But finishing them with plain water or oil or lather or whatever you are going to use, it will last for a lifetime. There might actually be still out there coticules quarried by Romans :p

I like finishing a razor on the coticule off a 4k. I'm not trying to reduce wear so much as get an idea how long this stone will last at that rate. I use a DMT 600 to create a slurry and to lap the stone. But from these responses, it sounds like I shouldn't worry too much about wearing the stone down. It also sounds like I don't need to have a perfectly flat stone to work off off? I like that vacuum feeling when a flat blade gets sucked to a flat stone, that's one of the ways I use to know that I've removed one more variable. Ryan82, if you haven't lapped your stone in 3 years, is it still perfectly flat, or does it not matter to you? I mean I feel like I don't need a perfectly flat stone for a rolling x stroke on smiling blades, but on a straight edge, I feel like it's necessary, even with an x stroke.

I have no coticule reference to compare to, but I feel like my stone is very soft. I am comparing it to a norton 1/4k, and a kitayama (mediocre synthetic finisher)

I have done thousands of razors on my Coticules. The only time I have lapped them is when I have dished them a little from either a Nagura or Coticule rubbing stone. I am in the camp of "Mostly Flat" is good. I really don't see wearing any of mine out in this lifetime.

Have fun.

thanks Lynn, that's reassuring. I've only ever had this one coticule, and I paid a good chunk of change for it, so I want to make sure I'm not mistreating it. I say I lap it often, but in my mind, lapping it means running it under the water with a big DMT a dozen or so times every 5 or 6 razors I do on it, just to make sure its perfectly flat.

Quote:

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Originally Posted by woodsmandave

thanks Lynn, that's reassuring. I've only ever had this one coticule, and I paid a good chunk of change for it, so I want to make sure I'm not mistreating it. I say I lap it often, but in my mind, lapping it means running it under the water with a big DMT a dozen or so times every 5 or 6 razors I do on it, just to make sure its perfectly flat.

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Mostly Flat is good and that stone stays mostly flat on it's own. You really should not have to lap that often at all in my opinion.

Have fun

I hardly ever lap my coticules, they don't need much lapping like a synethetic stone. They are non-porous like synethetic stones are so they don't clog with metal particles like the Nortons or naniwas and Shaptons do. Once you have your coticule flat you can use it for a long time without reflattening it as long as it doesn't become very dished like Lynn mentioned.

I didn't realize I have to treat the coticule different from my norton (with regards to lapping). This is good information. I think I can put my lapping plate away for a while. Thanks to all concerned!

I use my coti to lap a very hard, but very fine Jnat -as the final lapping stage, I should say. Have not seen a lick of wear and doubt I will in my lifetime.

I have yet to lap any of my coticules, can't say I never will but…