ATM (More!) tile tool questions

[Brian Yankee <byankee@fas.harvard.edu>]

I've read the list archives regarding making and using plaster and tile
tools and I still have a couple of questions before I start my own project.

First, has anyone used glazed tiles, but glued them onto the tool upside
down so that the unglazed side is up? Is there any point to doing this?

Second, what is the ideal (or minimum/maximum) spacing between tiles for
grinding 6" and and 8" mirrors?

Third, I plan on using the tile tool right from the start (hogging out
phase).  I realize that I may have to replace worn down tiles. My question
is, why doesn't this cause all sorts of uneven wear on the mirror?  It
seems to me that putting a brand new, unshaped, full thickness tile on a
tool that has been shaped by the grinding process would be potentially
disastrous. 

Thanks,

Brian



***********************************************
Brian S. Yankee
Production Manager,
Memorial Hall/Lowell Hall Complex
Harvard University
617/495-5595