Gold Plating Problems with Jewelry, How to make gold plating last longer? PVD?

A. Hi Vibhuti. Have you tried a 2k automotive clearcoat? I think it will be okay!

Regards,

A. Hi Ilene. It sounds like you're asking what you should make something out of if you are intend to gold plate it. Of the materials you listed, I think a brass or copper base, followed by nickel plating (or white bronze if jewelry), immediately followed by gold plating would be the best choice, and aluminum base would be the worst choice. But sterling silver would be better than anything you mentioned.

Regards,

A. Gold plating will not last. If you want a long-lasting gold finish, consider PVD.

Well, the gold plating on pocket watches has often lasted more than 100 years, Jim. But it was something like 400X as thick as what people want to apply today. 100 years divided by 400 = (left as an exercise for the reader).

Regards,

A. People have tried coating transparent hard substances like SiO2 on brass articles (and possibly on gold plating) by CEPVD / PVD though I am not sure with what effect. It appears worth exploring.

Am I totally wrong here, what is the problem in giving the costumer a thick layer of gold that lasts a lifetime. After all, gold is what costumer expects, when he/she buys jewelry.

A. It really depends on how intricate the jewelry design is. Balfour gave a presentation some years ago on class rings. They had moved from gold to PVD. Cost was an issue, of course, but a second problem is that the design work on gold would wear away over the years. With PVD, it would not.

A. Sorry Clive, but PVD means physical vapor deposition: it is a vacuum process done in a very expensive vacuum chamber; it's not an inexpensive kit. PVD is more appropriate for major manufacturers and their production runs than for an artist or hobbyist.

Regards,

A. Vacuum coating machine is widely used in stainless steel material; if the jewelry is brass or copper, then should do electroplating first, then use vacuum coating machine to do many IP color, rose gold color, TPU and so on.

A. Hi Paul. I'm no expert on this, but I'll tell you what I believe, subject to correction by more knowledgeable people ...

There is no real answer, I'm afraid -- because it's predominantly a question of what standard of quality and endurance YOU want to hold your product to, and whether you can realistically upscale the potential customers to that level of quality.

- As mentioned earlier, gold plated pocket watches lasted a century with, say, 20 microns of gold and up.

- The very highest quality gold plating on super-premium luxury watches today is probably about 7-20 microns.

- Vermeil, great quality jewelry, is a sterling silver base with 3 microns of gold plating.

- High quality costume jewelry, say gold plated sterling silver earrings, involves plating of about 1 micron.

- An earlier inquirer on this thread wanted to reduce his gold thickness below 0.05 microns (although that was on top of a gold-tone TiN deposit).

So, if you want to rely on the gold plating alone for the wear, rather than relying on TiN or a clearcoat or a gold-tone lacquer, consider: Cell phones, key chains, etc., are not heirlooms to be passed down to the next generation, and don't require 20 microns; but they suffer far more wear than earrings -- so you'd probably be looking at 3 microns for top quality.

But the thing is, if you intend to be a "me too" supplier, selling competitively, there is no way you can afford gold of that thickness :-(

That's why you will probably find it necessary to either apply TiN by a PVD process (which requires volume), or apply a clear or gold-toned transparent/translucent topcoat on top of your gold. I certainly hope you can sell real gold plating of a few microns, but it might be a difficult sell. Best of luck.

Regards,

A. Hi Fabio. I suspect that it is possible, since the ZrN or TiN is thin and great adhesion wouldn't seem to be a major issue -- but that you don't hear about it much because it is simpler and more conducive to single-vendor responsibility to just apply the gold by PVD since you've already done the ZrN or TiN by PVD anyway.

Regards,

A. It would need less investment both in gold and equipment if one could plate gold on TiN or ZrN coated watches. Once I tried to collaborate with an innovative plater. Though he could plate a few pieces, gave up saying it was not reproducible. It would be interesting to know if anyone is doing it. Or is it technically not feasible ?
I had seen some people trying to coat SiO2 on brass ware to prevent it from tarnishing. They were using plasma (RF) cvd. When I heard last, that was more than a decade back, there were some issues in commercialising it.

A. I believe [on eBay or Amazon] has a patent on a gold layer on PVD TiN, and used the method extensively on their watch bands. Eventually the gold wears off, but the color is close enough that the consumer can't tell. Not sure how they put the gold on. In the faucet and door hardware business the gold has been completely eliminated. PVD ZrN with additions of carbon can provide a wide range of gold finishes, as well as brass, bronze, and even nickel. A protective layer can be added to reduce fingerprint smudges, also applied by PVD. I don't know of any company using SiO2 as a top layer. It is hard to deposit. The PVD method of choice for decorative coatings is cathodic arc, and silicon does not arc well at all. It can be sputter deposited, but sputtering an oxide is a very slow deposition process.

A. Hi Marissa. PVD is capital-intensive and much more applicable to high volume jewelry than to a few pieces. Yes, you could clear coat your jewelry with a 2-component automotive clearcoat or with a UV-cured clearcoat similar to nail gel, but ...

Since your jewelry is sterling silver, it is not cheap -- and it doesn't deserve cheap plating, it deserves good plating. See my response below to Natasha for what I mean by that: at least 1 micron thick gold, and preferably 2-1/2 micron.

If you don't want to do the plating yourself, and jewelers won't deliver good plating, consider sending your work to a plating shop which specializes in jewelry. They will have the equipment, instrumentation, strict procedures, and quality ethic that you might not find in a local jewelry shop where plating is a minor sideline conducted in a small corner of the shop with inexpensive catalog equipment by people whose skills aren't primarily in plating.

Regards,

A. Hi Natasha. Many of the ideas on this thread have applicability, and we have a dozen threads on the same subject if you want multiple opinions ...

1. Both brass and sterling are fine. Obviously there is both cost and cachet involved if you say that all your jewelry is sterling. But additionally, gold can be plated directly onto the silver, whereas brass would probably require nickel plating before the gold plating. Back to cachet, if the gold plating is thick enough (2-1/2 microns) and the base is sterling silver, you can call it vermeil.
2. Electroplating is the only option available for applying the gold to the substrate in low volume custom applications. It can be done by brush (tampon) plating or tank (immersing) plating. There are a hundred and one proprietary formulations, but I would avoid solutions which involve cyanide because I assume you will not be doing this in an industrial setting. You should probably get access to a book about gold plating, as people who have spent a career in this art may find it a bit silly to think their lifetime of experience can be distilled down to a paragraph :-)
3. Micron gold (1 micron thickness) is considered good quality for costume ("artificial") jewelry, but if you want 3-5 years and more, and there is a possibility of wear, and you don't want to rely on clearcoats, then 2-3 microns would probably be best (search for "vermeil"). Today's most expensive watches might have 7-20 microns and some antique pocket watches had even more than 20 microns.

Mass produced costume jewelry may have little real gold, and may rely on clearcoats or PVD imitation coloring for durability. But if this is your artistry, involving hours of your own time, trying to save $2 on the cost of gold might be insulting yourself. A quick thumbnail sketch says if a piece of jewelry is 2 square inches and is plated with 1 micron of gold (.0000394") at a weight of 10.18 troy ounces per cubic inch and a gold cost of $1200 per troy ounce, the gold costs 96 cents. So 2-1/2 microns costs you $2.40 in actual gold; that would be the most you could save by going all the way from vermeil to no gold at all. Good luck. Sell quality!

Regards,

Thanks Ted!

Your response has really given me clarity!

A. Hi Nathaniel. "10 mils" (note the single l) means 10 thousandths of an inch, or about 250 microns. Super-premium watches costing many thousands of dollars get "7 mils", and I promise you that's not what you'll be getting :-)

"Ad-speak" isn't for the purpose of technically informing us, but for the purpose of inducing us to buy. Thus when you see "10 mills" advertised, it's something they want to "sound good" and not be critically examined.

"10 mills" is to my knowledge "ad-speak"; never heard it in engineering school or a plating career of 50 years. But obviously it means 10 millIONTHS of an inch (1/4 micron). This would not last long unless clearcoated, which it probably is. I don't think anybody can estimate the life for you; they can only say it's relatively cheap jewelry; calling it "heavy gold plated" is ridiculous because if it was 4 times as thick it would be "micron" jewelry (good quality costume jewelry) but if it were 7 times as thick it would still only be 1/100th (1%) of the thickness of the heavy gold plating on super-premium watches :-(

Regards,

A. Hello Gerald, if you are plating on brass you are going to need a barrier plate between the Brass and the Gold. For jewelry, nickel is not popular anymore due to allergic reactions. A white bronze plate is used a lot these days in place of nickel as a barrier plate. You may be able to find some "mini platers" used if you do some internet research. Plan on a cleaner, acid dip, white bronze plate, gold plate and all required rinses in between. The mini plating units are complete with required rectification. A used unit in good condition will run you between 1500 - 2000 USD. If memory serves me correct the tank sizes are 1 to 3 gallons. The chemistry you could buy "ready to use". You would have to seek a reputable gold bath supplier to have them supply you with a colour gold that you want. Colour golds are normally a deposit of 3 to 5 microinches. Hope this helps!