Quote Originally Posted by eKretz View Post
It isn't so much clogging of the stone that makes it cut finer, it's mostly the rounding over of the peaks/points of the abrasive particles in the stone. On most stones this happens much faster when using water than when using oil - as the coefficient of friction with water is much higher than with oil - so the stone wears faster. In effect, the particles dull with use.
Yeap. I'm of the opinion that a stone, coticule in particular, ought be used as-s prior to modification these days. Sitting back and mulling it over, there's a pretty noticable difference in the way my coticule behaved after being simply flattened up with my DMT 327 vs having spent hours trying to round over those roughed up particles, and then larger difference still after yet more hours of scrubbing the surface with the slurry stone to gently abrade away the ones that were damaged by the DMT and smooth the stone further still.

Mine was bought new from Ardennes, perhaps I would've been better served to use the stone as it came. After my first round of flattening it didn't feel like a finisher at all. Slowly over time I was able to smooth out the surface and make it work as I surmise it would have as it came from Ardennes. If someone spent years with oil on their stone and shaving off the results you might well wreck a perfectly good honing surface (if finishing is what you're after) by lapping it flat first then giving the stone a trial run.

But this is off topic. I use mineral oil on my coticule, cut with mineral spirits. For finishing we're using less pressure and generally want a finer/thinner oil. Ballistol, WD-40, mineral oil thinned up a tick with something etc. I also use a slick/thin shave lather, and just water on the same stone as I'm still playing with it to see what it likes. You're not going to hurt it with water, oil, or soap. If you use oil, just give it a wipe down with mineral spirits when you're done and no one will ever know there was oil on the stone. IF you get a stone that was used with oil and you want the oil off it, chuck it into a bucket of simple green and let it soak for a few days. 3 or so. I've removed some fairly heavy oil from old stones that way. You can't tell the difference between my Yellow Lake stone that was likely used for decades with oil and my Purple Slate from AJ on Ebay that's never had a drop of oil on it. If it's non porous the oil won't soak in deep, if it does soak in a few days in simple green or some light lapping will take care of the problem.