[Jewelry making - Article 00029] - Re: [Orchid] Curing investment under pressure for casting

[Charles Friedman]

========[ Invite a Friend - http://www.ganoksin.com/invite.htm  ]========

    Speaking as a dentist I would like to add something to this: 

    It would be typical to us a vacuum mixer for the investment. There
    probably would be little additional benefit in finishing the setting
    of the investment under preasure. If the investment was just
    mechanically mixed without a vacuum, then preasure curing might be
    useful. I have never read about this process. 

    In order to achieve an excellent fit of the casting on the tooth,
    many steps and materials have to be balanced to arrive at just the
    right amount of expansion. One of the techniques was hygroscopic
    investing. The investment would be vacuum mixed and then the casting
    ring would be allowed to finish its setting while submerged in water.
    I have not used this method. The differences in dentistry to balance
    expansion and contraction would be much much less than a ring size.
    That is why we pay more for materials from impression to wax to
    investment to metals. The whole system of materials and techniques
    have to work together. 

Charles Friedman DDS
Ventura by the Sea
____________________________________________________________________
T h e   O r c h i d   L i s t
Open Electronic Forum for Jewelry Manufacturing Methods and Procedures
____________________________________________________________________
Orchid FAQ:
~ http://www.ganoksin.com/orchid/faq.htm
Orchid Archives:
~ http://www.ganoksin.com/orchid/archive
Orchid Galleries:
~ http://www.ganoksin.com/orchid/gallery.htm
Invite a Friend:
~ http://www.ganoksin.com/invite.htm
____________________________________________________________________
Tips From The Jeweler's Bench - Article Archive
~ http://www.ganoksin.com/borisat/tip_sear.htm
The Jeweler's Selected Bibliography List
~ http://www.ganoksin.com/jewelry-books
Buy Orchid Jewelry:
~ http://www.ganoksin.com/shop
____________________________________________________________________
-Unsubscribe:
-Email: orchid-request AT ganoksin.com Body=unsubscribe subject=blank
____________________________________________________________________