YES it is much more
difficult to sharpen ceramic blades due both to the extreme hardness
AND the tendency of creating micro-chips on the edge. BUT it is not
impossible to both repair small damage or chipping and also to
polish and refine the edge to a very high level of sharpness.
The ideal tool of
course is a powered diamond wheel with a minimum of 1,000 grit
diamond. Even finer grits can be used to truly polish the edge.
However, no one I know, except myself, is willing to purchase this
kind of equipment.
Polishing the edge to
get a higher degree of sharpness if it does become uniformly “dull”
can be accomplished with very, very fine silicone carbide wet/dry
sandpaper. This is not a fast process but does work and I have
been including a small strip of 1500 grit paper with knives sold.
Put paper on top of mouse pad or piece of cardboard to provide some
compression & better control of knife angle. Now draw the blade
away from the edge, (do not cut into the paper), with only a slight
elevation of the back of the blade. 20 strokes on each side and then
test the edge. You can use from 800 to 2,000 grit paper. Start
coarse IF there is more than just polishing required.
Grinding out chips or
damage to the edge or re-shaping the edge
really only possible using a diamond hone. Powered would be really
fast and then you can use a very fine grit. Using a small diamond
hone (such as I am now offering for sale at $8.95) with a 600 grit
does permit fairly quick removal of ceramic from the edge. I have
found that 600 grit offers the best comprimise between rapid removal
of material AND an acceptable working edge . Water is used as a
lubricant and no more pressure than you would use with a steel blade
on a hone. These diamond hones can be used on your steel knives but
keep in mind that you will find the steel is VERY RAPIDLY removed
from the edge! Actually a very useful tool to carry in your wallet!
DETAILED DESCRIPTION OF SHARPENING
A great review of a Kyocera Kitchen Knife, but the only really well
researched guide to sharpening a ceramic blade without an expensive
powered very fine grit diamond wheel! My description of using Silicon
Carbide paper is taken directly from this review!
Do not try to use any coarse diamond
files or round/triangular rods. These will chip the edge as will most
commonly used sharpening tools. A powered diamond abrasive with very
fine grit 1,000 or finer, will produce a clean edge but may require
further polishing to remove scratches and micro chips for the absolute
best edge! I have found that a small 600 grit diamond coated steel
plate does work very well to re-define an edge or remove chips etc.
Actually a good working edge but further polishing with 1,000 &
1,500 grit SC paper will further improve this.