Thread: Chromium Oxide
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Old 07-29-2008, 08:45 PM   #6 (permalink)
Chris L
 
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Quote:
Originally Posted by PonderingTurtle View Post
I have found that you can buy it for about $12 a pound at various rock pollishing web stores.
The reality of using chromium oxide .5 micron powder for our purposes (final polish of razor edges and maintaining edges) is that the powder goes such a long way, the amount the size of a large almond could last someone a year or two if they use it to apply to a strop or two and also put some on newspaper for stropping. Seriously. A pound of chromium oxide .5 micron powder in volume would be about the size of a tennis ball or more. My point is, much much more than anyone would ever need for our purposes.

The other point that is rarely brought up is that the chromium oxide we use is quite hygroscopic ("the ability of a substance to attract water molecules from the surrounding environment through either absorption or adsorption")
The wiki definition.

That could be bad for stropping delicate edges on what used to be powder but after being stored improperly for potentially years, could end up being unfriendly hard gritty chunks, etc.

If someone gets into restoring blades and has a vibratory tumbler, I think larger quantities of chromium oxide make more sense. Even then going through a pound of it when only a little bit would be needed to refresh the polishing media would take quite a long time.

Don't get me wrong, the stuff wouldn't be hurting anything if someone buys way more than they'd need, but I'm just saying be sure to make room on your shelf!

Chris L
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