[Jewelry making - Article 00130] - Re: [Orchid] Platinum rings - which alloy is best?

[K L]

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

Hi Matthias!

    Thanks for your email. 

>     two years ago I purchased a pair of 960/40 Pt/Cu wedding rings here
>     in Germany and I want to tell you a bit about the characteristics.
>     Maybe you take a trip or order them here, if you hear about the
>     facts? 

    Yes, I've heard Germany generally has a positive variance when it
    comes to platinum content. Which is really nice. :) Congratulations on
    your purchase. Are the rings flat or domed? I guess platinum market
    in Germany is bigger than the Swedish dito so I don't mind purchasing
    my rings overseas. We're still looking for the best option.

>     Yes, the platinum rings are not scratch resistant. But every type
>     of gold ring will do the same. The difference between gold and
>     platinum alloys is: platinum moves around (you were right about
>     this) and gold will loose weight. 

    I've owned several gold rings (18K) and they scratched terribly in no
    time. But if you say plat.rings scratches but gives a nice patina
    rather than ugly scratches, then I would not worry much about
    scratches anymore. My concern is that we are planning to put a stone
    in her ring later (she prefers wearing one ring only) so the Vickers
    is a crucial factor I guess. 

>     In fact, all the scratches on our rings add up and give some type
>     of matte finish. We think it looks very fine. I would like to add,
>     it is impossible to produce a ring that will keep a mirror finish
>     over a period of more than some months. My rule of thumb is: Mirror
>     finish gets duller, matte finish gets brighter when a ring is worn
>     on a daily basis. 

    Yeah, I know what you mean. Some Swedish jewelry shops claimed the
    opposite - more or less said platinum was almost scratch resistant
    and that was one of the reason my g/f and I wanted to buy platinum. As
    it turns out, the huge wave of information I've gotten so far from
    the internet, Ganoksin and emails like this one, platinum Scratches. 

    And you're correct - mirror finished metal will probably scratch, no
    matter what Vickers and how careful you're with them. I own some
    watches that have been mirror-polished from factory and was extremely
    careful not to put scratches on them - but in a matter of few days,
    hairline scratches appeared. This leads to me thinking that rings
    will scratch a lot easier since a watch is somewhat more protected
    from environmental abuse than a ring on your finger. 

    I do imagine, however, that a polished metal that gets scratches will
    look better than matte-finished metal that gets shiny 'here and
    there'. 

>     Why? Copper makes it a lot stronger, cobalt even more! 

    Call me obsessive or weird, I prefer having an alloy that comes from
    the same Plat.group. :-) Perhaps I have to give up that one too. :)
    I've read about rhodium plating and use of Cobalt etc was not a great
    idea. 

>     No. After welding, the rings get soft. It is crucial that after
>     welding, the rings must be cold worked to get strong enough. 

    As a total newbie I am - cold work means hammering and such? 

>     Now for some facts about Pt alloys. According to my informations: 
>     999/1000 Pt reaches 80 HV when 50% cold worked. This is not
>     sufficient for jewellery pieces like rings. 
>     960 Pt/Cu reaches 180 HV when 50% cold worked. 
>     950 Pt/Co reaches 220 HV when 50% cold worked. 
>     You see: There are improved alloys compared to those they want to
>     sell to you. 

    Thanks for info! I didn't know cold worked 999 plat. could render a
    hardness of 80 Vickers! Then it might be true what e.g. Pilot and
    other companies claim about their 1000 plat. hardness. 

    I was told that if you want a stone set in a prong, then 80 Vickers
    is not hard enough, but if you plan to put the stone in the body of
    the ring, it should be sufficient. (if I've understood correctly) 

    More about cold working - what does cold work 50% mean? 

>     Hope this helps! 

    Thanks Matthias for contributing with your opinions and tips! Much
    appreciated. 

Best regards
Keo

____________________________________________________________________
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
____________________________________________________________________