The authoritative public forum
  for Metal Finishing since 1989
-----

Is 24k Gold plate the best underlay for rhodium?

I am a flea market seller seeking the best quality (lowest cost, too, of course) Rhodium for chains.

Rhodium is a hot commodity because it does not tarnish and in Florida that's a good thing.

I read the best plating method used by one jeweler and came to the conclusion that rhodium binds best to 24k.

I have 24K gold plated chains with a rhodium overlay. Is this a good or a bad thing?

Karyn Tighe
retailer - Cape Coral, Florida, USA
January 29, 2008

---

Karyn,
The rhodium or imitation rhodium will eventually wear off, then you are left with the yellow gold showing on the chains. I do agree that adhesion values are better using a soft (24k) gold. The grain structure of pure gold plating is better to accept subsequent overlays, but should not be the deciding factor for the use of an underplate.
I have to differ on plating 24k gold and then covering it up with rhodium or imitation rhodium. Is it just because you can market 24k gold plate on chains? You can't see the gold, so why is it plated? As you probably know it is most likely just a flash coating anyway (less than 5 microinches of thickness).
There are more economical underplate choices out there that are nickel free, and imitation rhodium solutions that are commonly used on costume jewelry. When the top coating does wear off you will be left with a similar color other than yellow gold.

Mark Baker
Process Engineer - Syracuse, New York
January 31, 2008