Marcus Hanke
[PuristSPro Moderator]
11296
What I hate: PVD gold watches
Once again, I am presented a nice golden watch, and have to read: PVD gold. What is this? Traditionally, we all know "gold plated", "gold filled", "plaqué" or "doublé".
For these designations, there are precise legal standards, especially in Switzerland, laid down in the so-called "Edelmetallkontrollgesetz" (control statute for precious metals), dealing with all kinds of objects either made from massive precious metals, alloyed p.m., or unprecious materials coated with p.m.
According to this statute, a gold, silver, platinum or palladium plating has to be at least 5 microns (=micrometers) thick, and has to be stamped with a small sign confirming this, followed by a hallmark showing who is responsible for the article production.
As we all know, watch cases with an electroplated (=galvanically applied) gold coat of 5 microns is not really valuable. In Fact, this thin coat is easily scratched, and the watch case will reveal the base metal, steel or brass. Better plaqué watch cases employed a gold coat of at least 10 microns, which became somewhat a standard in the watch industry. Even better were cases coated with 20 microns, which in everyday use was good enough for an entire watch life, without the base metal ever shining through. Just for comparison: an average newspaper page is about 60 to 70 microns thick.
Since a while, however, plaqué watch cases seem to have disappeared from the market, to be replaced by gold PVD. Sometimes, even quite expensive watches would have cases or case details with gold PVD ( I saw a 4,000+ Euro Seiko chronograph with gold PVD details on case and bracelet). What is this?
Unlike traditional galvanical procedures executed in a liquid, PVD applies a metal coat by the deposition of the precious metal as a vapour in vacuum. the sense of it is the application of ultra-thin metallic coats. Consequently, the gold PVD layer is not more than 0.3 microns thick (less than a 1/30th of even a thin traditional gold plaqué layer!).
Normally, this extrmely thin layer is rubbed away already in everyday use within a very short time. And yes, it is - but the wearer does not notice it. The reason lies in a trick, a gold-colored second layer below the gold, made from unprecious titanium nitride. This PVD layer, with an average thickness of 1 micron, is extremely hard and is not likely to be scratched hard enough to reveal the steel base below. So what the owner and wearer of a gold PVD watch actually is looking at, after prolonged daily use of his watch, is to a large extrent only the gold-colored titanium nitride, and not gold, which was rubbed away since long already.
Consequently, the Swiss law does not permit gold PVD articles to wear any designation of its gold content (carat, or something like 585), nor any hallmark. These cases are treated like plastic ballpens with a hairthin and purely decorative gold coat.
In my opinion, the current trend towards gold PVD watch cases or bezels, bracelet links etc. is close to a fake, even if it is correctly labeled PVD. But by using the term "gold PVD" the industry creates the assumption that the value is somewhat similar to traditionally "gold filled" or "plaqué" products without being even close to that.
Regards,
Marcus
This message has been edited by Marcus Hanke on 2013-07-17 15:59:24
What I hate: PVD gold watches
Truly educational
