The Plating Omega used on their movements

[Andy F]

There is nothing (in my opinion) as attractive as the rose gold colored plating on an early Omega movement. Conversely, there is nothing as sad as plating that is tarnished or polished. Does anyone have a process they use to properly care for the plating? Are certain solvents to be avoided? Is there a way to improve on the appearance of a tarnished movement?

 

[sleepyastronaut]

According to this site, the "unique reddish gold color" is due to a "copper-electroplated beryllium-bronze alloy"

https://www.kenrockwell.com/watches/omega/constellation.htm

Photos: Tim Mackrain

 

[mac_omega]

sleepyastronaut

According to this site, the "unique reddish gold color" is due to a "copper-electroplated beryllium-bronze alloy"

https://www.kenrockwell.com/watches/omega/constellation.htm

Photos: Tim Mackrain

This information is wrong. There is absolutely no Beryllium bronze in this plating at all.
It is indeed rose gold plating and the tarnishing is caused by oxidation of the copper part in the alloy.
When researching for my book I had some samples sent to the University of Salzburg to have the plating material analysed.
Only the very first rose colored platings had much more copper in the alloy and only very low gold content - hence these platings deteriorate much more - sometimes you can find them nearly black.

Edited: May 12, 2024

 

[sleepyastronaut]

@mac_omega ,

I believe what's intended on the page above at kenrockwell.com is that the plates and most other movement parts are made from a beryllium-bronze which is subsequently electroplated.

If he's incorrect about the electroplating being copper, he could also be incorrect about the base alloy.

 

[gatorcpa]

mac_omega

This information is wrong. There is absolutely no Beryllium bronze in this plating at all.

So is this article wrong?

http://members.iinet.net.au/~fotoplot/rgold/rgold.html

The author had a metallurgical study done as well.



Just want to get to the right answer here.
gatorcpa

 

[mac_omega]

gatorcpa

So is this article wrong?

http://members.iinet.net.au/~fotoplot/rgold/rgold.html

The author had a metallurgical study done as well.



Just want to get to the right answer here.
gatorcpa

Yes, this is wrong. Neither plates nor plating have been Beryllium bronze. I had this confirmed with a watchmaker at the Omega museum.
Berkavicius and Delury have not offered any information about the techniques, range or precision of the analysis that was carried out.
It was so unsatisfactory for me and I wanted to clarify this problem to be able to give proven information in my chronometer book. So I contacted my home university and asked to carry out some analysis. They did the tests with SEM (scanning electron microskope) which should be the best technique available. They have tested several different bridges I had sent them. The results were interesting: The first (unstable) rose gold plating consists of 85-90% copper, 10% silver and 3% gold, 3% zinc - it tends to oxidise and sometimes it turns black. The later (improved) plating which we can see on younger movements consists of 10-20% copper, 80-90% gold, 3% zinc. If you have my book you will be able to read all the details from page 60 - 67 (8 pages are dedicated to this topic). Hope this helps.

 

[mac_omega]

sleepyastronaut

@mac_omega ,

I believe what's intended on the page above at kenrockwell.com is that the plates and most other movement parts are made from a beryllium-bronze which is subsequently electroplated.

If he's incorrect about the electroplating being copper, he could also be incorrect about the base alloy.

I have discussed the topic "Beryllium bronze" with the watchmaker at the Omega museum. He told me that in vintage movements the only part which was made from Beryllium bronze are parts of the balance (Glucydur balance). No other parts!
It may be different in modern movements - but only small parts which have to stand high pressure or abrasion are made of the hard Beryllium bronze. Other parts (plates, bridges) are made of brass which is easier to work on - Beryllium bronze is very hard (compared to brass) and "wears out" the crucial parts (blades) of the lathe or other production machines very fast, so much higher costs in production...

Edited: Feb 24, 2021