[Jewelry making - Article 00163] - Re: [Orchid] Anodizing small niobium tube in silver brooch

[Marlin Cohrs]

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

Felicity,

    After I sent the reply email about anodizing, I thought I would give
    it a go to see what happens. After a frustrating 30 minutes, I came
    to the same conclusion as your last post. Attach the brush to the
    cathode (is it now cothodizing? :-) and it works great. I had a heck
    of a time coming to this conclusion. I thought my power supplies or
    my brushes were bad, but I could bath anodize Tantalum, Titanium and
    Niobium - but no luck with the brush, something I have done many
    times - until I reversed the polarity. Anode to piece, cathode to
    brush. It worked fine. 

    A couple of possible trouble spots would be if the electricity
    "shorts" through the silver. The colors on the reactive metals
    develop because as the oxide layer forms, it provides an increasingly
    resistive layer. silver will not do that, so if too much silver is in
    contact with the solution, it just shunts through the solution to the
    silver. 

    I also tried the bath method (which I suggested might not harm the
    silver). DON'T DO IT. The result is some strong discoloration which
    does not go away with reverse polarity. There may be solutions out
    there that would work (Speed Brite?), but neither TSP nor NaHCO3
    (baking soda) are friendly to the silver. They may well lead to a
    useful patina however. 

    At least I was able to do the anodizing with a brush on the Ag/Ti
    piece. 

Marlin, in a cool rainy Denver
I
____________________________________________________________________
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
____________________________________________________________________