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

A. Hi again, our well-traveled friend from Sweden, Los Angeles, Dallas, Oregon, & New York. I don't think there is any such thickness measurement as "macro"; please try to give us an exact quote about the gold thickness, in context. Thanks!

Regards,

A. Hi Far. "Micro" only means "one millionth". But you can be virtually sure that the thickness is not 10-15 millionths of a meter (10-15 microns) because the world's most expensive gold plated watches aren't even plated that thick these days. So he probably meant 10-15 millionths of an inch, i.e., about 0.25 to 0.38 microns.

Unfortunately, we have no way of knowing whether he was telling the truth, and we do not attempt to evaluate items here anyway. But 0.25 to 0.38 microns is probably typical for costume jewelry / imitation jewelry.

Regards,

A. Hi Steven. There is almost surely a clearcoat over the gold plating, and it probably ought to last a few years, according to general expectations of merchantability. Unfortunately I don't think there is any way to hazard a better guess.

Regards,

A. Hi Steven
Ted is quite right. Clearcoat should last a couple of years. Without it 24 kt gold on its own is thin and very soft.
In my opinion it is a totally unsuitable finish for any domestic surface subject to wear like regular cleaning.
Of course, clearcoat detracts from the appearance of gold and it usually ends up looking like brass.
So why not save a small fortune by just buying clearcoated brass fittings?

A. Hi Bev. If you wear it only occasionally, you could wrap it in an anti-tarnish cloth, or put anti-tarnish materials in a drawer with it. But practically, the only thing you can do is make sure you bought a different brand this time.

Regards,

A. Hi Patrick. Modern nickel plating baths are "self leveling", so surfaces that will be nickel plated do not require mirror polishing. But two provisos: first, I am not necessarily sure that a home hobbyist will achieve proper self-leveling unless you have some experience; second, the fact that nickel plating does not require a mirror-finished substrate doesn't mean that it can cover and conceal all scratches; up to a certain depth it will cover them, but beyond that it will emphasize them. If this is an old watch case, chances are it has some scratches which the nickel plating will emphasize rather than cover.

Regards,

A. Hi Kaye.

adv.
Here is a 'kit' from Gold Touch [a finishing.com supporting advertiser] for $499 at the time of writing .

There is really nothing special about the $3000 price range. Electroplating for the purpose of a science experiment can be done at no cost, and with stuff already in your kitchen; and at the other extreme a plating installation for depositing a single metal can cost $10 million or more.

If you have not done plating before, my own feeling is that you should do the kids free science experiment plating first ("Electroplating -- How It Works") to quickly understand the science behind electroplating, at least at a grade school level. I would then consider buying a kit and some copper plating solution and trying some copper plating and clear coating of jewelry. To me, the main issue with gold plating is just that experimenting and trying to learn the basics using a metal which costs $1000 an ounce is a costly way to go :-)

Additional comments are welcome! ... but sorry, we can't post comments mentioning or suggesting specific brands of kits (why?).

Regards,

A. Ted is right. Gold is awfully expensive to experiment with; you should start with something simpler.
Does the kit include gold stripper for when you get it wrong? We all do sometimes!
I would want a spill tray for when you break one of those glass beakers (not if).
Do you have cleaning chemicals; and know how to do a water break test?
Do you intend to do a nickel undercoat?
How do you intend to dispose of unwanted chemicals (local regulations) and have you considered first aid when some gets on your skin - or in your eye?
And was that reel of wire in the photo tinned? You should use bare copper to avoid getting tin or lead in the gold.

$3000 is a significant investment. A local plating company could do a lot of work for that.

A. Hi again Kate. Until you've acquired some plating experience there will be no easy way for you to be assured that you applied the required thickness either :-)

Plating shops do plating for medical parts and aerospace ... it's possible to find trustable ones. Ask them for a "cert" (certification) regarding the gold thickness, while you practice with copper electroplating/electroforming. The same equipment you use for copper can be used for nickel and gold after a learning period.

Regards,

A. Hello Aran, did the plating company use a barrier plate (diffusion barrier)? There are a few things to consider. If the company you chose did not use a barrier plate between the brass and the gold the brass will migrate through the gold and cause the color change. If the gold plating is too thin, migration is accelerated. The plater should have told you barrier plates are commonly used for gold over brass. If they plate copper over the brass before the gold the same scenario will take place.

A. Hi Zee. Rhodium is only for silver or white gold rings because it is silvery color. It is not an answer for yellow rings.

Regards,

A. Hello Ibrahim, with hard gold plating of 25 microns you won't have any porosity issues. With that thickness the pores will be closed. I've never had to plate gold over 100 microinches, and you would be approaching 1000 microinches. You would be at the very high end of the gold plating thickness spectrum. The oil and gas industry often require greater gold thicknesses, as well as atmospheric condition considerations. A gold strike bath is employed by many shops to improve adhesion of the top gold layer and reduces drag in of metallic contaminants to the main gold plating bath. The strike bath is a low metal concentration bath without any alloys. Be very careful of brittleness in the deposit. Have some bend tests done on a regular basis. As gold purity decreases the deposit is less malleable. Good luck in your venture.

A. Hi Ibrahim

I have electroformed many parts in a standard nickel hardened acid gold (Metalor) to a thickness of 1 mm
There was never any sign of brittleness.
It is usually accepted that over 5 microns there is no porosity or diffusion issues.

A. Hello again Ibraham, your parts being brittle depends on how clean the plater keeps their gold bath. As other metal contaminants are introduced into the bath through drag in, the gold purity drops and could result in parts being brittle. If good rinsing and good housekeeping is employed there should be no problem. A pure gold plate under the hard gold would not make any difference as far as parts being brittle. You can ask your plater if his gold bath supplier regularly checks for metallic contaminants when they do routine analysis. Good luck!

A. Hi Rosie. Vermeil is very high quality jewelry and should not require e-coating. I have heard of 'gold coloring' which involves putting a final layer of the exact color you want on top of a substantial layer of regular gold plating, however, it usually runs the exact opposite way of what you describe. Usually a heavy coating of yellow gold might be 'colored' rose or green via a thin top coating.

Your vendor's story isn't ringing true for me. It sounds to me like he has an inventory of rose gold (instead of yellow gold) pieces that he is offering to you by applying a final topcoat of yellow gold. I don't think you should normally have to worry about vermeil changing color even in years or decades ... let's see if an experienced jewelry plater can say something :-)

Regards,

 Thanks Neil!

A. Hi again, Rosie. I'm only suggesting the possibility that they perhaps may have had a stock of rose gold plated items and decided to meet your need by putting a flash of yellow gold on top of that. But I'm not claiming that these parts, which I haven't even seen, do or don't meet the quality standard for vermeil.

Speaking as a former 'expert witness' on a half dozen or more court cases in the USA though, I unfortunately must inform you that nothing you can read on the internet will ever constitute "a professional opinion". I doubt you would take legal action on "samples", but to do so you must retain the services of an expert; the opposing side will then challenge his/her credentials and the judge will rule. If any volume is involved, you probably should get a jeweler to evaluate just exactly what you received. Good luck.

Regards,

A. Hi Jose. It sounds like you are trying to judge the quality of some jewelry from its seller's sales pap, and that usually doesn't work :-)
"0.25 m" obviously doesn't mean meters. Maybe it means "microns" to you? 1 µ thickness used to be considered fairly good quality costume jewelry. In fact, it was frequently just called "micron jewelry". These days 1 micron is probably hard to find in the mass market, so I guess I'd call 0.25 µ thickness (10 microinches) "okay" quality. 0.03 µ seems almost impossibly thin -- are you sure what units 0.03 was referring to?

Regards,

A. Hi Pat. My opinion is only my opinion, but I would not proceed on a project that way. Proceeding based on theory alone is something you do only on moonshots when testing is impossible and you have a large budget and can pay the best people in the world to do detailed research. Plus, neither you nor I is an expert on bangles -- the shops who make and plate countless thousands of them are; I could suggest that copper is easy to plate, only to have you find the bangles ripping off their chains because it was too soft. Finally, if they do a poor job you probably have no realistic recourse no matter what you spec'd anyway.
I would only work with a manufacturer I trusted and I'd ask them what they recommend. Good luck!

Regards,

A. Hi Rosie.
Things are sometimes a matter of scale. Even fairly small engraving of initials, trademarks, etc., strike me as much much bigger than the ridges on fingerprints. Although I'm not sure that I fully understand, I can certainly believe your supplier.

However, what I still absolutely do not understand is any need to clearcoat vermeil :-)

Regards,

? How thick is the gold? Do you have a diffusion barrier (nickel or palladium) under the gold?

A. Firstly, what purity gold are you depositing? Secondly, what is the alloy base? Thirdly, how thick is the gold? Fourthly, do you have any interlayers between the gold topcoat and the alloy base?
It sounds to me like you have too thinner gold layer and it is porous. The black and green could come from the alloy base or any interlayer you chose to use. However, to give a more comprehensive answer, you need to give more details.

A. Hi Sylvanus. First off, I'm no jewelry expert and this is just 'book knowledge', I'm just trying to offer the courtesy of a reply -- so I certainly encourage others to chime in.

I don't think there is an answer to your question because rings suffer extreme wear; bracelets probably quite a bit less, but still an awful lot; necklaces and earrings less than that; and pins and broaches almost none. And that's before we even consider that different people treat their stuff much differently, for example, swimming and washing dishes with rings on vs. off.

But one answer is that 0.25 microns is ten millionths of an inch, and standard aluminum foil is 63X thicker. So without a clear coat it probably won't last long except in a very low-wear situation. A clear coat is probably called for.

Perhaps a better answer is by comparison to other jewelry. I believe that the cheapest gold plated jewelry you will find anywhere is about 0.06 microns; this is probably just enough for a gold color and is used under a clear coat. Your thickness of 0.25 is probably similar to most average quality costume jewelry these days. "Better quality" costume jewelry is sometimes called "micron gold" because it is 1 micron (4X your thickness) and that was probably the typical thickness several decades ago. Vermeil is about the highest quality non-karat jewelry you'll find, and is 2.5 microns thick on sterling silver. The gold plating on super premium watches was reportedly about 7 microns (although today they probably use titanium nitride as well as gold to prolong the life, so the gold thickness might be less).

So I think the question of how long will it last is not answerable, but the question of where you will fit in on the quality scale is :-)

Luck & Regards,

A. Hi FK. I'm all for quality, even super quality, but vermeil is 2-1/2 microns and would probably last a decade on a necklace. I can't swear to it, but I've heard that the world's finest super-premium watches were using 7 microns of gold until TiN became available, so it's probably TiN plus a couple of microns of gold these days.

Although silver & gold interdiffuse, it's a slow process at room temperature, and probably not a serious concern for vermeil or greater gold plating thicknesses (my opinion based on my limited experience; always get multiple opinions on matters of this import), but for thin gold the nickel or other bright plating underlayer is required for brightness as well as to stop diffusion.

Luck & Regards,

A. Hi Sama. First things first, I'm not 100% sure what you mean by "0.05 gold plating micro", but if it means 1/20th of a micron of gold plating, I think it's silly to use expensive sterling silver as the substrate for very cheap jewelry ... and you'll probably need nickel plating below it, and surely a good clear coat on top of it anyway if you want it to last a couple of months.

I certainly can't call it "good quality" when the vermeil that FK feels is too thin for his high quality jewelry is 50X as thick. "Good quality" is a matter of personal opinion, but mine if that 1 micron (40 millionths of an inch) is "good quality" :-)

Luck & Regards,