Re: ATM (More!) tile tool questions

["Gil Stacy" <gstacy@premierweb.net>]

>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.

Unlikely on a six or eight inch mirror that you'd have to replace ceramic
tiles.
Most tiles that I've used have been slightly over .2" thick.  Although I'm a
true believer
in hogging with a metal ring, I don't know if I'd bother to do so on a six
or eight inch mirror with a moderate curve, particularly if I already had a
flat base to mount the tiles on.  I roughed a six inch F/5 with tiles
epoxied to fiberglass screen and paraffined to a spare six inch blank in a
relatively short time.  Total time spent was less than had I used a ring and
poured a tiled tool.  On bigger stuff, metal rings are the only way if you
need to hand generate a curve.

 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.


Normally not so.  You'd be able to know after rough grinding whether or not
to add tiles.
Also, it is easy to seat tiles with 220 carbo.  Before I learned the ring
trick, I ground a larger mirror from the flat with a flat tiled tool. The
sagitta was deeper than the tile thickness. I epoxied another set of tiles
on top of the ground down tiles. It was aggravating, but doable, and won't
happen again.

Gil