[Jewelry making - Article 00324] - Re: [Orchid] Sparex No 2 101

[John Burgess]

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

G'day;

    Doing it in copper vessel, acid is used up reacting with copper and
    the result is copper sulphide and water* 

    The reaction between hot strong sulphuric acid and copper produces
    sulphur dioxide, which is a nasty choking gas, and not copper
    _sulphide_ but copper _sulphate._ There is little point in using a
    copper vessel. A glass Pyrex or Chance beaker or flask is excellent.
    There is little point in boiling the acid as warm sulphuric acid or
    'pH down' works well at about 40C to remove sulphide stains from
    silver or low carat gold. (copper sulphide stain in this case)
    Silver, gold, platinum or other of the 'noble' or precious metals
    will _not_ react with sulphuric acid or the sulphate ion.-- 

Cheers for now,
JohnB of NZ
____________________________________________________________________
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
____________________________________________________________________