Re: ATM tools

["Bill T." <twentiethwave@hotmail.com>]

Ken Lowther wrote, regarding ATM tools:
> Aluminum or iron would be fine.  Of course having the ROC beforehand is
> nessecary with these materials.
>
> Porcelain is very nice.  About the same harness as the glass we grind.
> Give or take.

Iron grinding tools are really great.  Their big advantage over tiles or
glass is that they only minutely change shape doing a typical grind.  You
can reliably grind tool or mirror on top for the entire process, a great
advantage when using machines.  Their lifetime is in the hundreds of
mirrors.

He who perfects affordable metal tools for large mirrors will be a
certifiable Hero of ATM.  Glued metal washer tools come kinda close, but
IMHO aren't that great for the finer grits.

I investigated cast Porcelain tools.  My ceramicist friend advised that is
almost impossible to fabricate large ceramic pieces more than a fraction of
an inch thick.  If thick casts don't crack during drying (which may takes
weeks of months), they almost certainly will during firing.  The upshot was
that Porcelain tools would probably make plate glass look like a real
bargain.

Bill T.