Internet Horology Club 185
Rhodium plating

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https://ihc185.infopop.cc/eve/forums/a/tpc/f/9886009961/m/4351008522

January 05, 2007, 17:28
Dan Mitchell
Rhodium plating
To what extent was rhodium plating used in the 1920 -1936 period in the production of white gold watch cases. I'm told it was used to stop the gold tarnishing.

dan
January 06, 2007, 09:51
Cary Hurt
Dan,

I know that Gruen used Rhodium plating on both white gold and on sterling silver cases during that period. I believe that it's use on gold was simply to provide a "whiter" (ie, more like platinum) appearance, as 14 karat white gold shouldn't tarnish any more than yellow or rose. On their silver cases, they were advertised as being "tarnish-proof".

I believe from observation, but have no documentary evidence, that others followed the same practice, including Bulova, Benrus and possibly Hamilton.

Regards,

Cary
January 13, 2007, 00:43
Cort Moore
I'm pretty sure that new chain still has rhodium plate. Basic spools of sterling silver chain sold by Otto Frei and everybody else has rhodium plate or some similar treatment to keep it looking bright. I can't buy it. I search for fine sterling chain for lady's pendant watches and also for men's pocket watch chain. If it has been adulterated with plating, it isn't usable. Who wants to see a lovely sterling watch hanging from a "night of the living mirror" chain?

On a similar vein, I sold a nice Chelsea 8" ships's clock today. The beautiful brass case was half/half not plated with a plating that probably looked OK for a year or two after it was sold. Since it wears off so quickly,unevenly and unattractively, I wish they hadn't bothered!
-Cort
January 18, 2007, 00:50
Cort Moore
Here are two pics of an old Rhodium plated case.
I would guess it dates to the late 1920s. I took the first pic on my mouse pad with a flash light so the mirror chrome color is off. The reason it is interesting will be apparent in the next pic.
-Cort


January 18, 2007, 00:56
Cort Moore
The inside reveals the case is bright orange and 18K gold!

I must add that this case was aquired empty for five dollars. It was a while before I found a stray movement, dial, hands,crown,crystal, band.........
At least I didn't scrap it! It runs fine too!I've hauled it from show to show but have found no interest in it(full disclosure may be working against me). Actually, I'll be sad when it does finally go as we've spent a lot of time together Smile.

I should mention that, although it seems screwy, the plating of 18K gold is a completely logical choice. Because 18K is virtually tarnish free it bonds extremely well to plating. There is no plating degredation on this watch.
-Cort


April 18, 2007, 12:13
Dan Mitchell
I have recently closely examined a number of 1930s Hamilton white gold-filled wristwatch cases. In several the center portion is more of a gray-white color, while the bezel and back is a brilliant shiny white, almost chrome-plate in quality.

My conclusion is that the bezel and back may have been rhodium plated, but that this was not thought necessary for the center section.


dan
April 19, 2007, 11:10
John Johnston
Dan,

Is is possible that the plating done to these early 1930's Hamilton's was done after the fact after they left the factory?


John
April 19, 2007, 14:30
Dan Mitchell
Yes - always possible.

As I understand it white gold was/is difficult to make, so even today white gold jewellery is often rhodium plated. We need comments from an expert like Will Roseman on this.


DM