McMaster-Carr carries silicon carbide grit in various sizes (along with
a million other things).

http://www.mcmaster.com

Bob Weiss N2IXK

Smokey wrote:
In the 1960s I ruined many a crystal following the guidelines found in ham
publications then for raising the frequency of my FT-243s. Of course I used
Comet or Ajax since that was all that was available. Now, lo these many
years later I am ready to give it a go again only this time I'd like to try
it with carborundum grinding powder. I have checked the local hardware
stores and the response is typical for the Jasons and Jareds who have no
business working in such a place. When they ask you to repeat "carborundum"
its a sign they'll be of little help. I've tried automotive parts stores
and, while carborundum is used in cylinder compound it is mixed with some
other chemicals I am not sure would be good for my quartz. One idea was the
guys that polish rocks and collect them. Hobby stores? So where do YOU find
your carborundum? I'd like to know because I can't find it. Even the people
at the glass etching place in town thought I was gargling when I said the
word "carborundum." Thanks for your suggestions.

de W9STB

I have ground 6 MHz crystals up 1 MHz - just to see if I could do it. I
grind in a figure 8 pattern using fine sanding paper. I often use 600 grit
to speed things along.

I use a small square piece of glass I got from the garbage can of the glass
cutter at the local hardware store.

Clean well after grinding.

It took me one NBA basketball game and two cold beers to go up one MHz. If
you secure the glass plate, you can grind with one hand and drink with the
other.

I now have a large box of ham crystals - even made a nice label for it.

73, Colin K7FM