Gold plating on sterling silver, Vermeil

A. Hi Neelima. A barrier layer of palladium would be ideal. A hard 18K gold plating of Vermeil thickness could last a lifetime in a low wear situation like a broach, and a few years on necklaces and bracelets. Although your mileage may vary, the gold plating is 2-1/2X as thick as micron gold which is considered moderate quality. And the jewelry could be clear coated on top of that.

Luck & Regards,


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

A. Hi again.
Yes, but this question doesn't seem to flow from your previous one, and is abstract, so there is great potential for misunderstanding each other ...

Firstly, although gold can be applied by PVD processes, when people use the phrase "PVD gold" they are usually referring to gold colored titanium nitride coatings, not real gold. These are usually applied on stainless steel or nickel-chrome plating not directly on silver. It seems a little strange to start with real sterling silver jewelry and then put imitation gold on it. It seems more practical to start with stainless steel or nickel-chrome plated brass, and then apply the PVD titanium nitride.

Whether real gold is applied by plating or PVD the same diffusion issues would apply; Real gold PVD is usually for very thin coatings, not for 2-1/2 micron vermeil.

Experts can spot the color difference between real gold and titanium nitride but my eyes aren't good enough. I understand that some premium watches include PVD titanium nitride coatings followed by a thin gold coating to give the correct color.

If you're looking for the cachet of vermeil -- authentic gold on sterling silver -- PVD coatings are not the path forward. But if you are just looking for wear resistance and a general gold color, PVD titanium nitride coatings on nickel-chrome plated brass (or even stainless steel) are probably more practical and cost effective than vermeil. Of course, you need sufficient production volume to support PVD processes.
Luck & Regards,


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

A. It is not advisable to directly electroplate pure 24 karat gold over sterling silver. A barrier is needed between these two metals. Thin layers of electroplated gold will diffuse slowly into the sterling silver substrate and eventually will develop a dark green to grey color.

Try polishing the silver surface first with a buffing wheel. Clean it in a ultrasonic cleaner or any neutral solution.( Do not use any strong acid or alkaline solution) . Dry it and give a "bright nickel flash" plating first. Bright nickel flash plating solutions may be purchased from any precious metal plating vendors. One such company is Technic of Warwick, Rhode Island. After rinsing and drying, you may now acid gold plate the part successfully on top of the bright nickel surface.

A. Hi. Yes, the nickel can be problematic these days, and is probably forbidden in Europe. White bronze plating (an alloy of three metals) is an accepted substitute, but you probably must buy this as a proprietary solution from a plating process supplier as it is very tricky to formulate and operate white bronze plating baths.

Regards,

A. The finish you want is the finish you should achieve before plating. So if you sand blast your item to give it a satin finish, you will be able to plate and maintain the same finish.

Rhodium

Vermeil

A. Hi Gail,

"White gold" rings are made of white gold (this is an alloy of gold plus whitening agents like nickel or palladium) and they are then rhodium plated for the brightest white color, brilliance and scratch resistance. If you are interested, we wrote an FAQ on "Understanding White Gold & Rhodium Plating" to quickly explain exactly what white gold actually is, and why it is usually rhodium plated today.

Vermeil is not a type of plating; rather it means jewelry that is made of sterling silver which has then been gold plated 2-1/2 microns thick so it looks like solid gold. Read on, and Neil Bell explains that Vermeil is not just a "look" but has a legal meaning you would need to comply with.

Vermeil is probably fine for all kinds of jewelry. But remember: because of where & how they are worn, and that they're often worn every day rather than occasionally -- rings get so much wear that any plating on their surface has a rather limited life.

A. Sure, they can be gold plated. There might be a gold plater near where you live, or you could check with jewelers or better department stores. they sometimes have contacts with plating shops which will do consumer goods.

Pierced Ear Protectors

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A. If you like the look of the sterling silver, but are allergic to the metal the best thing to do is buy the plastic sleeves that fit over the posts and the plastic earring back. a set of six sleeves and backs can be purchased at your local department store (example: Wal-Mart, K-Mart, Target, etc.) for under $5. I have the same problem and they work for me.

"Gold Plating Technology"
by Reid & Goldie
(hard to find & expensive; if you
see a copy cheap, act fast)


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A. Hi, Stephen.

One thing in your favor is that the average purchaser is not doing careful cost comparisons; rather, they want to spend $xxx on a present for their wife and get something pretty. Another thing in your favor is that precious and semi-precious metals are expensive, so the cost of labor is proportionally not as important in jewelry as in commodity items.

Yes, gold plating on silver will diffuse into it (mix with it) leading to tarnish, and the work-around can be an initial plated layer of something like nickel plating or white bronze that does not diffuse with silver or gold. But if the plating really is 100 µin. thick, it can take a good while for that diffusion.

As for business success, if you bring something to the table -- be it outstanding salesmanship, an irrepressible enthusiasm, or a real flair for jewelry design -- success is certainly possible. But we encounter similar questions on other topics like bronzing of shoes, and we tell people that being able to sell the product is the most important part! If you can't sell the shoes, there's no sense making them; and if you can sell them, there's no need to actually make them, you can just re-sell them and let somebody else do the grunt work :-)

Please focus on how you can market your product, how you will find distributors or jewelers, how you will get people enthusiastic about what you have to offer. If, after you do that, you decide that doing the plating in a domestic house would be a useful part of the plan, then you can investigate the potential downsides of that idea. I would hope that your plan can work with the electroplating being done in an industrial rather than domestic setting because it does involve the use of dangerous chemicals. Good luck.

Regards,

A. Vermeil is 2.5 microns of gold over sterling silver and will last longer than an item plated with only a few millionths of an inch of gold but it is not solid gold. If you want the performance of solid gold then that's what you should purchase.

A. Hi, Charles. The gold and silver will tend to diffuse together, so it is best to have a layer of nickel plating between them (or white bronze if this is going to Europe). Please see thread 52625 for more info on the diffusion issue. Good luck.

Regards,

A. Are you sure that the silver purity is .950?
Sterling silver is .925 silver and can be marked sterling or .925 along with your trademark.
You will need to gold plate your sterling jewelry at least 2.5 microns thickness to label it Vermeil.

A. Marc. I think you are seeing silver migration through the gold plating. That would imply that the gold is very thin, less than one micron.

First off, you should have a reputable lab measure the gold thickness, then either increase gold thickness to 2 or 3 microns, or plate a nickel barrier between the silver and gold.

"Gold Plating Technology"
by Reid & Goldie
(hard to find & expensive; if you
see a copy cheap, act fast)


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A. Hello Himanshu. If you have the patience for a careful search, the topic of durable yet affordable gold plating has been covered in detail many times on these pages. But it is difficult to get a consensus for many reasons, including: some people are satisfied with a gold "look", while others demand real gold; PVD coatings are very economical in high volume but prohibitive in low volume; electrocoating is economical in medium volume but not practical for custom onesy-twosies.

Still, to summarize in a single paragraph: thick gold plating would easily do it -- gold plated pocket watches have lasted a century -- but it is considered far too expensive today. So if you do not want to put on enough gold to last three years, you must either replace some or all of the gold with a titanium nitride or similar PVD coating (which will only be practical at high volume), or you must clear coat it.

I suspect from my reading here, but do not know from personal experience, that white bronze plating, followed by "micron gold" (gold plating of thickness 1 µ / 40 microinch), followed by a good clearcoat (preferably e-coating, but UV hardened coating if volume is too low) would be considered good quality for costume (imitation) jewelry. My guess is it might last 3 years of rather occasional (not every day) use. Good luck.

A. Hi Michele. Engagement rings are worn every day as well as being very high wear items. The bad news is that no practical amount of gold plating will last through your marriage. If you go to a specialty jewelry plating shop, and they apply a lot of gold, and then apply a top quality clear coat, it might, maybe, last a couple of years.

If the ring was a family heirloom, get used to the silvery color; it's the best answer. If the jeweler sold you a new engagement ring and then plated it a different color, he really should have known better; there was no chance of long term success. If you and your fiancee can accept the change to such an emotionally charged item, get a yellow gold setting.

P.S.: I vacationed on your beautiful island last year; Secret Harbor is the nicest beach I've ever seen -- so where can you travel to for your honeymoon that could be better? :-)

Regards,

Hello,
If the marriage will last longer than the gold plating consider it a blessing!!

A. Hi Elly. As you may know, there is no isotope of gold that is white -- white gold is an alloy of yellow gold with palladium and/or nickel. I'm not personally aware of white gold plating being available; it's not easy to get different metals to electroplate in the right proportions to form the desired alloy and correct color, and it's possible that it hasn't been achieved. Platinum or rhodium plating are possibilities.

This plating can be very thin, and will not at all interfere with ornate patterns. I think your best bet for the candlesticks would be a thin layer of rhodium plating. Silver items often receive a thin plating of rhodium to deter tarnish that doesn't completely detract from the look of silver. I don't think I would rhodium plate flatware though because I've never heard of it; and although I wouldn't anticipate any safety issue, I wouldn't want to be the only family in the world trying a health experiment; plus it's too thin to work for long. If you learn of the availability of rhodium plated flatware, that would change things.

Sorry, we can't suggest vendors (why?).

Regards,

A. Hi Richard. Yes, your band can be plated either with rhodium to retain the silver look or with gold. The gold plating could be very heavy if you're willing to pay for it. If a local jeweler can't do it, plating shops specializing in jewelry probably can. Still a ring worn everyday endures extreme wear; you've probably seen rings worn all the way through, let alone through the thousand times thinner plating.

You may or may not like the look, but it might also be possible to clearcoat it yourself with automotive clearcoat or UV-curing lacquer. Good luck.

Regards,

A. Hi Prakash. Patents are on the internet in our modern world; do the search. Naturally, unless you only want to do one for yourself and try to fly below the radar, you can't do them yourself without licensing the process from the patent holder anyway.

Regards,

A. Good day Tam.
Try the company TECHNIC, they are a supplier of gold plating solutions.

Best of luck. Regards,

A. Hi,
I have owned a pair of Vermeil Earrings for 31 years now. I did find that they tarnish, but I found a way to bring them back to brand new condition. I have a liquid Silver dipping cleaner that I use on them and they are as beautiful as the day I purchased them. So, easy to say that Vermeil is my preference for long wearing Jewelry, but hard to find these days.
Suse

A. Hi Vic.

Usually available on eBay;

sometimes on
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free pdf is currently available from academia.edu

Let me quibble over a possible semantics issue first :-)

Unless I am misunderstanding what you are doing, most of us might call it electroplating rather than electroforming. The difference being that we call it electroforming only if the plating layer itself becomes structural, for instance if you were plating gold onto wax and then melting the wax away to create hollow gold earrings, with the gold plating becoming the object. Microwave guides, record stampers, and flexible bellows are some other typical electroforms. But I am not sure that I understand after all :-)

Faraday's Law will tell you the thickness of gold plating you would get if your process operated at 100% efficiency (with none of the electricity going to the liberation of hydrogen instead of deposition of gold). The Metal Finishing Guidebook ⇨
has a handy chart on page 812 which integrates the various conversion factors involved in Faraday's Law calculations and ends up giving you the number of Ampere-Hours per square foot required to deposit 0.001" thickness of plating. For aurous solutions it is 6.2, and for auric solutions it is 18.6. From this 3:1 variation you can see that you need to tell us what kind of gold plating solution you are using before we can get too far; it's probably aurous, but your vendor can certainly tell you. Efficiency can also vary widely: it's usually 90-100% for cyanide golds but can be somewhat lower for neutral golds, and significantly lower for non-cyanide or bright acid gold baths.

So, as you can see, it isn't possible to estimate the thickness you are depositing from the time and current without some input regarding the gold plating solution being used.

There is no "accepted thickness". We have dozens of threads here discussing the topic of gold plating thickness, and it ranges from zero (tinted electrophoretic lacquers or PVD hard coatings in lieu of gold), through a few tenths of a micron for very cheap costume jewelry, on to about 1 micron for moderate quality costume jewelry, then onto 2-1/2 micron gold plating over silver (Vermeil) for high quality, all the way to 7 microns and even more for super-premium watches.

Get back to us with more info and the readers can probably offer additional responses. Good luck.

Regards,

A. Silver will migrate thru 3 microns (0,0001 inch) of gold in a very short time. Insert a layer of palladium for a diffusion barrier.

A. Hi Jimmy. Our colleague Robert is almost alway right, and he may be right that a diffusion barrier is worthwhile ... but I personally don't believe it's the cause of your posted problem.

Luck & Regards,

A. Hi again. Are you sure you are doing thorough DI rinsing? If you have a vapor degreaser in your facility you could try using it immediately after plating (parts still wet) as a "vapor dryer" and tell us if it changes anything.

Luck & Regards,


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