[Jewelry making - Article 00169] - Re: [Orchid] Firescale Prevention During Vacuum Casting

[Daniel Ballard]

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

Hi,

    One source of oxygen/fire scale is the airborne oxygen. However,
    there are other elements that get involved from the plaster
    ingredients, and the high heat. Sulphur dioxide for one example. 

    When we use a reducing atmosphere either hydrogen/nitrogen or heaven
    forbid-carbon monoxide, we still see fire scale. So we still use
    deoxidisers of one kind or another for best results. As further
    proof, use a good oxygen free atmosphere to cast an ingot in a steel
    mold. You will notice far less fire scale/oxidation compared to
    plaster cast gold or silver. 

Daniel Ballard

____________________________________________________________________
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
____________________________________________________________________