Gold plating imitation/costume jewelry

A. Hi Jayanta. I'm sure the readers can help you, but not without any information. Do you know how thick you are plating?

Although some gold deposits are a bit harder and longer wearing than others, the most important factor is the thickness ... if you are putting on only a thin plating, it will unfortunately not last long. If you can't afford thicker plating, consider clearcoating. Good luck.

Regards,

Q. Hello sir
Thanks for responding to my letter; my next query is: What is the process of clearcoat? Is it long lasting? Is it available in kolkata? Is it cost effective?
Thank you.

A. Hi again Jayanta. "Clear coating" simply means applying a coating that is clear, and there are many different technologies to do it: Asif Nurie mentions electrophoretic lacquer (electropainting) as one approach. Automobile paint uses a two-component clearcoat as the top layer. Women who have their fingernails polished often use a UV-cured clearcoat to prolong the life. There are nano-ceramic clear coatings as mentioned in letter 59642. There are lacquers and single component clearcoats ...

Although I'm not a jeweller and have no real experience, my first thoughts are that because you run a "small electroplating shop" ...
a). The capital cost and space required for an electrophoretic lacquer line is probably not practical.
b). Automotive clearcoat is cheap and available everywhere -- you can certainly try it, although it's not optimized for jewelry use.
c). UV curable clearcoat is worth considering -- it can be a very hard surface, and can be cured with a UV lamp that costs well under $100.
d.) If you buy your gold solutions from Technic or Degussa or another known vendor, they can probably also offer a nano-ceramic coating.
e). Lacquers and air-dry single component clear coats are probably not hard enough and thick enough to substantially improve the life of gold plated jewelry.

Regards,

Q. Sir
Can I use Dupont 2-component lacquer as protective coating on jewellery? Is it long lasting?

How can I do gold plating on an egg? Can you please give me the necessary steps.

Thanks.

A. Hi again. We don't compare brands here, but I've just finished telling you what little I know about the use of 2-component automotive clear coat as a protective coating on jewelry. Please try it and let us know what you find.

Please see letter 001 for gold plating of eggs. If threads about gold-saving measures for costume jewelry veer off into how to plate eggs, then people & search engines can't find what they're looking for. I'm very of guilty doing that over the years and it's been a real struggle trying to sort the threads back out :-)

Regards,

A. Hi Monica. I doubt that the plating is 0.03 micron (1.2 millionths of an inch), as I don't think you could even get any gold color from such a thickness. I'd suspect that inexpensive jewelry might have 0.3 microns (12 millionths of an inch) of gold followed by a clearcoat.

But you already know the answer to your question: the jewelry is turning black in 4 months, and you have multiple complaints, and neither you nor your customers are satisfied with it. What more can be said about its quality?

Regards,

A. Hello, just an addition to Ted's comment. I agree this is not quality decorative jewelry. Because the gold plating is directly on brass tells you a lot. The brass is migrating to the gold layer because there is no barrier plate between the brass and gold to prevent the migration. As Ted mentioned the .03 micron thickness of gold is hard to imagine. Most jewelry makers will use a white bronze or nickel barrier plate.

A. Hi Russell. Sorry, no it's not. Electroplating does not move small particles (atoms) intact. It dissolves metal into positively charged ions which migrate through the solution, and negatively charged electrons which are propelled through the external wiring. If you were able to maintain electrical contact to the pyrite such that iron dissolved into the solution, and if you were able to move those positively charged iron ions through the solution, when they regained their electrons at the cathode they would form iron not iron pyrite (FeS2) anyway.

That is not to say that it is impossible for any process to deposit FeS2 onto an article; it might be. But metal finishing is about depositing practical coatings, and even if you could form FeS2 on a surface, I don't know how useful it would be in terms of corrosion resistance, adhesion, wear resistance, etc.

A. Hi Ashish,

Q#1- If you are going to plate the pendents anyways I would suggest just holding off on the PVD coating and have them done together. No sense in PVD coating then sending them all through a plating line after. plating the sputter deposit will depend on the material that was evaporated and deposited on your chains. What is it?

Q#2- E-coat is about the best protection you can expect from a lacquer. That being said many people do not like lacquer on there decorative jewelry. I'm not fond of E-coat on high polished and hand engraved typed finishes either. If you use corrosion resistant materials when you plate you can avoid E-coat. Gold, Zinc, metals of the Platinoid family. That all comes with a higher price tag then the E-coat though.

Q#3- Whatever you use as a diffusion barrier in your gold process will be sufficient for a rose gold process. Ni, white bronze, Pt, Pd.......

Q#4- No. There are many "white bronze" type baths. The majority of which are comprised of Zn,Cu,Sn. It will have a white finish and be more corrosion resistant then standard 70/30 bronze due to the amounts of Zinc and Tin but can't compete with Rhodium. Rh is a Platinum family metal. Brilliantly bright and very resistant to elemental effects such as corrosion and discoloration. You can try Pt, or Pd, as the market is not as volatile for those metals and much more is mined as far as annual tonnage but they are also much more pricey.

For jewelry that is intended to be inexpensive, the "white brass" might preform fine. I could only suggest you plate a hand full of parts that will be typical of the parts you intend to sell and try them out in the real world. Apply them to conditions you believe your products will face and then check them for defects to find if the finish is acceptable. Hope this helps.

A. Hi Van. 24kt gold never tarnishes, and if the plating is thick enough it can last for many years ... but I doubt that that is what you have.

If it feels like and looks like aluminum maybe it is. It's possible to anodize and dye aluminum so it will be scratch-resistant and long lasting, but I'd be surprised that it would fool people into believing it's gold. Try archimedes experiment as a simple way to learn if it is in fact aluminum.

But it could also be a titanium nitride finish (which looks a lot like gold -- there's a lot of titanium nitride coated bicycle chain out there). Another thing it could be is real gold plating with a robust clear coat (like automotive clear coat) on it.

Send a good pic to for posting here. Despite how impressed you are by this finish, I doubt that you will find any testing lab so impressed that they will test it for you for free. But you might visit a large local scrap yard and see if you can talk them into aiming their "scrap tester" x-ray fluorescence machine at it. Good luck.

Regards,

A. Hello, Royce. Your questions are good ones, but the actual problem here is that long-lasting jewelry can be produced using any of these methods, but so can low quality jewelry :-(

If supplier A suggests that he offers only 5 months, he's probably right; if you want more than that, you'll need a different supplier. If supplier B says 2-3 years, what warranty/reimbursement will he offer to you if the life is substantially shorter?

The "best" technology is very thick gold plating. Century-old pocket watches owned by the robber barons sometimes had 20 µm or more of gold plating; super premium watches of today reportedly still use 7 µm plating. Vermeil is 2.5µm on a sterling silver base. But such thicknesses are too costly for even very high quality jewelry today, and obviously out of the question for imitation/costume jewelry where the gold plating thickness is probably in the 0.2µm range. So methods of getting by with lower gold thicknesses were developed, including putting a clear coating on top of the plating so it would not wear out as fast, and substituting PVD-applied TiN coating for some or all of the gold. There is no lower limit to the thicknesses or quality, and wear is not the only reason things turn color anyway.

I think what you need to determine for yourself is whether there is an actual need for gold plating or not. If the color of the PVD is close enough, and you don't feel your customers care that it's not really gold, and you can avoid the word gold plated in your advertising, then wear-for-wear PVD coatings will probably be cheaper. Silver is a "better" base than stainless steel, but more expensive. Brass is probably a better base for electroplated finishes, but not for PVD finishes.

If you want second opinions, this long thread with its dozens of replies is only one of many here. Search the site for "gold pvd electrocoating" to see hundreds of additional opinions. Best of luck!

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Mooney said it all, but left me thinking, how about the PVD Titanium/Nitride topped off with clear polyurethane?

A. Hi again Royce. That eBay article changes the subject and talks about silver vs. stainless steel as a final finish, saying that stainless doesn't tarnish as badly. But you are talking about which is better as a basis for a gold finish, and that's a different question.

As previously mentioned, gold plating can range from 0.2µm or even less to 20µm. There is no way anyone can estimate the lifetime of jewelry from such vague info as 'gold plating plus clearcoat'.

I am not in your position and have zero experience trying to market jewelry; sorry I have no idea what the customers' expectations & preferences are. Further, trying to judge quality from sales pap is simply impossible. If you are not familiar with the two companies, and can't find reviews, and can't get references from them, and can't get warranties, it is a crapshoot. Both technologies are widely used because both can produce high quality and low quality jewelry, but some companies are far more reputable than others.

Hopefully a reader who sells jewelry will offer some input.

Regards,

 Hi All!

So I have decided to order samples first from both companies and will test how it does over time. Thank you for the very informative and fast reply. Wish you all the best!

A. Hi Jay. We appended your inquiry to a thread which discusses some of the possibilities. There are many popular approaches from gold-toned lacquer on nickel plating, to PVD coating processes, to gold-colored brass plating, to very thin (and thus inexpensive) gold plating followed by a clearcoat. It's hard to suggest one approach over the popular alternatives to it, but if you tell us the anticipated production volume, type of jewelry, substrate material, price point, and desired longevity, that might eliminate some of the possible choices. Good luck!

Regards,

A. Hi cousin Sagar. 3 months is a very short life, which you should be able to meet easily. Yet you have already attempted to implement -- and then dismissed for lack of success -- three whole technologies ... so you are now hunting for a fourth potential technology to solve your problem.

Yet all of those technologies have been used successfully. Please understand that people mean no disrespect when they say that the problem is probably not that those technologies don't work, but that your implementation of them is not careful enough. Metal finishing processes are finicky, and they require adjustment; they need clean and properly activated metal substrates; they need highly purified and quality-controlled ingredients; they need carefully maintained operating environments; they need skilled personnel who recognize immediately when something is not proceeding properly and know what corrective action to take.

My guess is that lacquering or otherwise clearcoating the brass will be the cheapest, easiest, lowest technology, fastest leaning curve approach and that it will last 3 months if carefully implemented. Try to find some brass lacquer or clearcoat supplier with good experience, or a clearcoating consultant, who will work with you; then follow their advice to the letter and I believe you will have a solution.

I assume that the 'stones' are merely glass, not cut gemstones, if the jewelry is only expected to last 3 months? I would expect that the radiation-cured clearcoats used on automotive headlights would result in almost non-detectable loss of shine. Best of luck!

Regards,

A. Hi Melissa,

I have read that pens advertised as "gold plated" may actually be PVD coated with >20 alternating layers of gold and TiN (titanium nitride). The outer layer would be gold of course, but as it wears away, it will reveal a layer of gold coloured TiN.

Perhaps you could employ a similar process?

TiN coatings can be extremely durable, but how durable you can make them will depend on your PVD machine.

I myself have been trying to achieve a 24 carat gold coloured TiN coating, but haven't quite been able to get there. However, I have managed colours ranging from champagne gold to 18 carat.

A PVD machine capable of depositing TiN will also be able to deposit blue, black, grey, silver, and bronze coloured coatings.

A. One of the early uses of PVD for decorative purposes was to deposit TiN then follow with a layer of gold because you can't get the 24 ct. look from TiN. However, you can get 24 ct. look from ZrN by adding a little carbon to the coating. Many in the door and faucet hardware industry use this for their gold color. Much easier and cheaper than gold on top of TiN, and the coating is actually harder than TiN.