Sterling - Rhodium and Nickel Plating?

I seem to be the messanger of truth and accuracy on another (non-
jewelry) forum. I have already corrected their white gold
misassumptions, the fact that 24k gold is “almost pure” gold.

This is the latest statement that seems wrong to me.

"While sterling silver does not contain nickel, some sterling
silver is plated with rhodium to prevent tarnishing, and then the
rhodium is often plated with a tough nickel coating. Usually I
warn my customers with nickel allergies to avoid “non-tarnish
sterling silver”. Now with Argentinium entering the market place
it may be harder for those with allergies to know what to buy. "

Why would anyone put nickel over rhodium?

Please, talk to me metal guru’s. Is there any truth in the above
statement?

Thanks.
Carla

Why would anyone put nickel over rhodium? Please, talk to me metal
guru's. Is there any truth in the above statement? 

No, and yes. You can’t rhodium plate silver directly - it dissoves
the silver (our solutions, anyway) and immediately trashes the
solution. However, if you nickel plate it, first, then you can
rhodium plate…

Good Morning, Sorry to inform you but I think you got it backwards…
Rhodium and silver are not a good match as eventually you will
pollute your rhodium. At over 4000.00 an oz. you really don’t want
to mess up your plating solutions These pieces are usually nickel
plated with rhodium over plating the nickel. I know it sounds crazy,
and I don’t like it. But most of these pieces are 10k white gold and
produced in China. Regards, Craig PS Your other comment on 24K not
being close to pure gold is merely a problem with your refiner. If
refined properly you can expect to receive gold that is.9999+.
Actually the in house refiner at a company I worked for was
producing fine gold at.99997. OK so it wasn’t completely pure, but
close.

I have a query. If you have a silver ring, for example, and you
nickle-plate it to rhodium it, you are looking at rhodium. Then you
have a white gold ring and you rhodium it, you are looking at
rhodium. The wearability (or wear-out-ability) of the finish is the
same. Where, then, is the value in using white gold versus silver
versus brass versus some base metal? They all look the same (?) and
the finish wears the same.

Just a query.

V.

I’ve spoken to several local jewelry repair people who have told me
that rhodium can’t be plated directly onto silver, and that one first
needs to nickel plate the silver, then plate the rhodium over the
nickel. But I’m confused:

Nickel is outlawed in Europe, so many of the silver manufacturers in
Thailand produced two different types of plating–one for their
customers based in the United States and another for their European
customers. As I understand it, the American customer’s jewelry
contains silver>nickel>rhodium finish, while orders being sent to
Europe are nickel-free silver>rhodium finish.

I didn’t assay any of the jewelry. However, the jewelry that
contained nickel was attracted to a magnet, while the supposedly
nickel-free items were non-magnetic. Interestingly, the jewelry
containing nickel had, in my opinion, a more attractive finish.
Nonetheless, I bought a lot of nickel-free items in order to avoid
problems with customers who have nickel allergies.

So what’s the story? How do Thai manufactures provide rhodium plated
jewelry to their Europe customers without using nickel?

On a related note, although I have no idea whether this is true or
not, an importer told me that a lot of the cheap silver jewelry
supposedly plated with rhodium is actually plated with tin! Any
possible truth to this?!

Doug

Where, then, is the value in using white gold versus silver versus
brass versus some base metal? They all look the same (?) and the
finish wears the same. 

Where to start?? First, the finish does not wear the same. If you
rhodium plate white gold, silver and brass - nickel silver is white
brass, essentially - you will get very different results. As the
white gold plating wears, you will barely be able to tell. As the
silver plating wears, the piece will start to look “dirty”, where
the silver comes through and oxidizes. The nickel silver will do the
same as silver, but it will get green spots and get real filthy -
and turn the wearer’s finger green. This is aside from the obvious -
the gold ring has $75 of metal, the silver has $3.50 of it, and the
brass has $0.25, and people usually want jewelry with inherent value.
More importantly, though, is that the white gold’s properties make it
perfect for jewelry. Silver is fairly amenable, too, but it has it’s
own set of problems - mostly durability. Brass and especially nickel
silver is almost impossible to work on a level of jewelry - it’s
easy to spin and stamp and do sculpture and stuff, but doing details
and soldering and stones is quite difficult - and then it’s only
worth.25 cents in the end…

Doug, You are recieving correct I know tin is a very
good base metal to plate over. I don’t know if they go straight to
rhodium or nickel first. The price of rhodium these days may make a
difference in the production of these silver items. We may see some
sort of alternitive to using rhodium. Usually the almighty dollar
dictates the rules.

So what's the story? How do Thai manufactures provide rhodium
plated jewelry to their Europe customers without using nickel? 

First off, all sterling silver in the world at at large is “nickel
free”. I don’t actually know the answer, but I know something about
plating. Probably they are gold plating the silver first, then
rhodium, which works well. I’ve never heard of tin plating, but
there’s no reason why not - except that tin looks more like lead
than rhodium - pewter is tin - some is 100% tin. It IS whiter than
lead, but it’s not rhodium, and it’s incredibly soft, too. Probably
it would also contaminate rhodium, too, if used as a preplate. There
are two recommended plating methods for sterling that I know of - one
is preplate with nickel, the other is preplate with gold, then
rhodium. Or just nickel plate and leave it at that. That does not
mean they are not doing something else I never heard of, but that
would be typical. The gold is just a flash plate to cover the silver,
and the rhodium’s not so heavy either, just enough to stop the
silver-tarnish thing.

Nickel is outlawed in Europe, 

It is a little more complicated than that. what is against the law
is a product that releases more than a certain amount of nickel when
exposed to an artificial sweat solution in a given period of time.
So an alloy can contain nickel as long as it will not release it into
/ on to the human body.

Jim