(ATM) ceramic tool quiry

[rhill@lpl.arizona.edu (Rik Hill)]

One thing I have used with great success is one of the cement
circular patio blocks. I would then seal it (don't use varnish as 
outgassing from this will act as a solvent on many materials
like pitch). You can then attach tiles, or any other grinding 
surface with blocking pitch, epoxy or another adhesive or a 
layer of blocking pitch with tempered polishing pitch on that. 
I have used this as a tool with mirrors to 18" diameter.

-Rik