Furnace to cast + Boules

I know there is no such thing buttt. Has anyone an idea how to build
a vacuum furnace 1.1200F to burnout 2.lower flask temp. slowly 850F
{while}, 3.melting metal under vacuum 1900F 4.switching from top to
bottom {without shock} to cast.

Also wanted supply of CLEAR synthetic spinel boules 20x50mm or
preferably larger? best cement? epoxy? to glue end to end.
Thanx Roy

You might find this kind of furnace used to cast titanium. I’m a
bit foggy about the fine points but I seem to remember that one of
the dental labs in town is casting titanium partial denture
frameworks in some kind of vacuum furnace/casting machine. I also
remember that the cost then ( 15 years ago) was about $15-20K!!!
Hope this helps

Mike & Dale, Lone Star Technical Services,
Your ultrasonic repair guys.

    Also wanted supply of CLEAR synthetic spinel boules 20x50mm or
preferably larger? best cement? epoxy? to glue end to end. Thanx 
Roy 

For sticking stones together in a manner where the adhesive will be
the only force holding things together I strongly recommend reading
Henry Hunt’s fantastic book “American Lapidary: Designing the Carved
Gemstone”. He goes into great detail with tons of experience in
different adhesives and there uses. He also talks about the
proceedures that work for him, as opposed to the manufacturers
recommendations. The 2 best for what you asked are probably Hxtal
(carried by HIS Glassworks
<http://hisglassworks.com/pages/hxtal.html >) or Duro-Crystal Clear
UV Glass Adhesive by Loctite (http://www.loctite.com/distributor/
for a location near you). The latter is a UV epoxy where you
traditionally use a UV lamp for curing. Although I understand that
those of us who are blessed to live in the Desert Southwest can
simply leave the stones lying around outside in full sunlight. I
have no personal experience with either, but I have spoken at length
with several artists who do.

Epaul Fischer
Gryphon Song Creations
http://GryphonSong.com