Alt Rhodium

[ed4copies]

Bear in mind that these products are being plated in Taiwan. While I am NOT an expert on plating, nor linquistics, I SUSPECT that they are not confined to using the same terminology nor the same formulae as American companies to make "the same" products. So don't be surprised if information is "modified in translation".

 

[jrista]

Technically speaking, pure rhodium is not actually that durable of a plating. So, as long as its still an alloy of precious platinum-group metals and has the same luster, but is more durable and won't flake off, I think that would actually be a good thing. In all my reading about this lately. I've come across a lot of pages covering the subject of re-plating jewelry that had rhodium platings that weren't properly alloyed for durability. Seems like its a common problem. I gather than the rhodium plated on top of nickel and gold is more durable, but, I don't know that its the most durable.

I get concerned when precious-metal alternatives replace precious metals entirely. Reading the response from Dayacom, it sounds like they have found an alternative metal to Nickel in a Rhodium-Nickel-Gold plating (which seems fairly standard), that may be more durable. If that is indeed the case, that should be good for us, as it would still be Rhodium-AltSomething-Gold.

 

[egnald]

The thing that caught my eye in the information posted by Sly Dog was the following:

Especially advanced countries like Europe is prohibit nickel plating that is sensitive to the skin, this problem can be easily solved by replacing the nickel layer with alternative rhodium plating solution.

Historically, a "Nickel Layer" has been used in industry as a diffusion barrier layer between the base metal (often some kind of copper or brass alloy) and the top plating layer (often some kind of precious metal). The diffusion barrier prevents copper in the base metal from diffusing into the top plating layer over time which changes the electrical properties of the plating above it. In decorative applications copper diffusion affects the color and/or appearance of the top plating.

Because Nickel has been added to the USA EPA list of 17 chemicals for voluntary reduction in industry (along with cadmium, chromium, lead, etc.), industry is paying more attention to replacing the nickel layer with other materials while maintaining the key properties of Nickel such as it being a diffusion barrier, it's tarnish resistance, it's wear resistance, and it's solderability.

Typical alternatives suggested for replacing an electroplated Nickel barrier have included the following:

Copper-Tin and Copper-Tin-Zinc (sometimes called "White Bronze")
Copper-Gold-Palladium, Copper-Gold-Silver, Gold-Tin, Gold-Silver, Gold-Indium
Palladium-Zinc, Palladium-Cobalt
Titanium Nitride

I am sure that cost as well as aesthetic appearance and wear resistance would have to be factors taken into consideration for the material to be used as a decorative final/top coat and not simply it's diffusion barrier characteristics. Of the materials listed above, the Copper-Tin or Copper-Tin-Zinc alloys have appearances that are the most similar to that of Rhodium. They provide good corrosion resistance and are hard and durable and are much lower cost than the alloys containing Gold, Silver, and Palladium.

But of course all of this is entirely speculation as related to the question about what "Alt Rhodium" really is. Only the electroplater knows what is in the special sauce. Honesty, if Dayacom does not do their own electroplating in-house, they might not even know what the true composition is.

Dave

 

[sorcerertd]

The one piece of information that I got Dayacom to divulge to me was that their hardware is all brass based, with whatever plating over that. A customer had asked me if an antique brass pen was solid brass and I really wanted to know the answer to that, too.

 

[DrD]

The plating formerly known as Rhodium? Maybe whatever was mixed with the platinum to make the Rhodium version (alloy?), but without the platinum? Oh, so many questions and options. I suppose we can call it "Proprietary plating that is more durable than chrome" (or is it?)

You bring up an interesting point. Several years ago before the turn to rhodium, there was the "platinum coating." I had read a review of platinum v chrome, as to durability, and if memory serves - very, very dangerous for a 77 year old mind - the chrome was more durable. Maybe it was not quite a lustrous - shiny - as the platinum, but it was reputed to be more durable. At the point, I made the conscious decision to go with only 2 coatings, 1) titanium gold, and 2) chrome. That worked fine until the TiG/Hardite kerfuffle came up.

 

[sorcerertd]

kerfuffle

Yes, this part. Chrome works for me, too. The clip on my personal carry rhodium plated cigar scuffed up pretty easily. Why spend extra for that?