One of the drawbacks of ceramic stones is that they are rarely flat.
I used a diamond stone to flatten my extra fine (about 1800 grit) and
my medium ceramic stone. It broke the glaze and left them slightly
mottled. However, this does not seem to have affected their cutting
ability and I continue to use them. This causes me to wonder if (1) I
am deceiving myself that they cut as well as before and (2) if they
can be flattened with a diamond stone why does the ceramic stone
manufacturer not flatten them since it would make them more desirable?
Anyone in this group tried what I did? Did it work for you?

They Should come flat from the factory.
At least the shaptons I have are flat.
I can't recall seeing any new stones which are not flat, though I haven't
checked recently.

1800 is not really extra fine is it? I'd call something like 8000 extra
fine.

Well, if you should find a ceramic stone finer than 1800 please let us

Well, if you should find a ceramic stone finer than 1800 please let us
know.

Well, if you should find a ceramic stone finer than 1800 please let us
know.

Joe

http://www.shaptonstones.com/stones/Professional-Series.php

120, 220, 320, 1000, 1500, 2000, 5000, 8000, 15000, 30000

I'd never use anything finer than 8000, but there is always the option.

Here is my experience with them.
http://masamiki.com/mono/tools/sharpening.htm

-j

I've heard of these Shapton stones and I do not believe they are true
ceramic stones (fused through extremely high heat) but are really a
type of Japanese water stone which use a different procedure for
binding the abrasives than normal Japanese stones. I am not saying
this with certainty and I could be wrong but I don't think so.
Ceramic stones undergo intense heat and it's the heating that distorts
them and makes it next impossible to create perfect flatness. I'm
sure there are people who understand this a lot better than I do and I
hope one of them will stumble across the thread and clear things up.

Joe

Well, if you should find a ceramic stone finer than 1800 please let us
know.

Joe

http://www.shaptonstones.com/stones/Professional-Series.php

120, 220, 320, 1000, 1500, 2000, 5000, 8000, 15000, 30000

I'd never use anything finer than 8000, but there is always the option.

Here is my experience with them.
http://masamiki.com/mono/tools/sharpening.htm

-j

When the US needed tiles to keep the space shuttle cool they went to Japan
to find the man to do this.

Shaptons are waterstones that use some sort of ceramic abrasive
instead of whatever regular waterstones use. They wear hollow just
like waterstones only more slowly, and should be flattened whenever
they get too far out. Flattening them does not reduce the rate at
which they cut.

Until Shaptons came along there was no confusion regarding "ceramic"
stones. These are ceramic through and through (as opposed to ceramic
grit in some sort of media). The coarse and medium grit ceramics are
made to fairly rough flattness tolerance - 0.010" if memory serves.
The fine grit ceramics are made to 0.001". They probably have to
throw out a lot of them because fines cost twice as much as mediums
or coarses. My understanding is that you cannot flatten a true
(non-Shapton) ceramic stone without compromising its cutting ability.
That observation was made during an old FWW review of various stone
types.

To restore most of the cutting ability of a non-Shapton ceramic you
scrub it aggressively with water, Comet, and a sponge.

To restore most of the cutting ability of a non-Shapton ceramic you
scrub it aggressively with water, Comet, and a sponge.