ATM 18" mirror Progress and Dental Stone question

["Damian Kruger" <djkruger@mpx.com.au>]

Hi List,
Does anyone out there have a source of dental stone in Australia? I'm about
to pour a 18" tool after hogging out my 18 " blank to a depth of 4mm (F 7)
by hand with a 5kg barbell weight, and 80 grit.  It's taken almost exactly 4
hours (yes four) to get there, quite quick compared to my 2 previous mirrors
with glass tools.  The desired depth is 5.71mm (F 5) and so to obtain it I'm
going to switch to a dental stone tool so I can get the curve to the edge
(currently 2-3" short) and get it spherical.  John Murray if your out there
I believe you had a source a while back.  For those who are about to suggest
seeing a dentist, has anyone had any luck with a sourcing from dentists?
Price?

Previous posts have indicated Dentists reluctant to sell it to people of the
street.  Currently I'm not chummy with any either!   For those interested in
the grinding logs for big mirrors I will post mine to the group (and put it
on a web page) at a later date so those who are contenplating grinding a big
one by hand  can see what they're in for.
Regards,
            Damian Kruger
            Cairns   Australia