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topic 53424

How long Gold Plating over brass will last? Will the zinc discolor plating?




A discussion started in 2009 but continuing through 2018

October 21, 2009

Q. I am trying to do .5 micron gold plating over brass jewelry. but my manufacturer said that it will get discoloration very quickly because of zinc in brass. he said Zinc will migrate with the gold and will cause discoloration.

He suggested I do first Nickel or palladium plating then Gold plating, which will help my gold plating last for more longer period.

I need expert advise.

Sunny Singh
jewelry - DALLAS, Texas, USA


Gold & Platinum Jewelry Buying Guide
from Abe Books

or

October 22, 2009

A. Hi, Sunny. I think you have been advised correctly. The gold and brass do slowly diffuse together if there is not a barrier layer of nickel between them. While this may not be a major problem at room temperature with thick gold plating, it may be with half micron thick plating.

Regards,

Ted Mooney, finishing.com Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


December 8, 2009

A. Hello,

In fact, a barrier layer shall be added between brass and gold.

Onto house-goods, we put a 5 microns bright nickel layer to avoid the problem of Copper diffusion into gold layer.

But, considering the new politics concerning "nickel-free processes" for jewelry, we have replaced the nickel barrier by a white bronze layer (5 microns) for the parts in permanent contact with skin.

Hope it can help you.

Nicolas Duthil
- Bordeaux, France



September 17, 2010

Q. I am doing high end 3 micron gold plated brass jewellery. My process is: copper plating on polished item, buffing, flash cyanide copper, palladium plating, micron gold and flash gold.

My question:
1) Can I use white bronze in between copper and palladium which my customer wants? I tried but could not plate anything over white bronze. It seems white bronze cannot be plated.

2) Can palladium be plated directly on brass. After buffing, at some places the plating wears off specially at the edges of the articles and hence the base brass gets exposed. Can I plate Pd directly on it? I tried rhodium but it attacks there.

Please help.

Regards,

DEBASISH BHATTACHARJEE
- KOLKATA INDIA


November 4, 2010

A. Hi,

You can always plate on top of Bronze, I think you have some problem with the chemistry of White bronze.

praveen kumar
Praveen Kumar
    plating process supplier
Mumbai, India




May 14, 2012

Q. I have a ring that says it is double layer of genuine 18k white gold and rhodium platinum over brass. Will that turn my finger green?

katie donalds
- duluth Minnesota


May 2012

A. Hi Katie.

Neither white gold nor rhodium will turn your finger green, but brass will. So if the plating is good and heavy and free of porosity you will be okay until it wears thin.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



May 27, 2013

Q. Hello!, I'm buying a bracelet from Europe and it's 22k gold plated brass, is that good? It says that it's non-tarnish but I will like to know from someone else too.

Thanks

Sara Stollreiter
- Guatemala


May 28, 2013

A. Hi cousin Sara. Unfortunately it is difficult to tell the quality of jewelry just from a seller's claims because their intention isn't really to inform you, but to induce you to buy. Yes, 22 kt gold plated jewelry is probably non-tarnish, and it can be fine, but the thicker the gold plating the better. If they don't tell you the thickness, it's probably not very thick at all. Good quality costume jewelry should probably have about one micron of gold plating on it. Good luck.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



December 8, 2015

Q. Hello I just purchased two bracelets, one says 18k gold over brass and the other just said rhodium plated over silver. Should I worry about tarnish?

Thelma Finnaman
- Egg Harbor City, New Jersey


December 19, 2015

A. Hello Thelma, the gold over brass will tarnish. The brass will migrate into the gold plated layer because there is no barrier plate. For the Rhodium plated, it would depend on the thickness of the rhodium plating. Rhodium is one of the hardest finishes as plated. Depending on how often the piece is worn would be directly related to the rhodium wearing off. The rhodium finish would hold up much longer than gold over brass. Sorry it took so long to respond.

Mark Baker
Process Engineer - Phoenix, Arizona USA


October 3, 2016

A. I have had bad luck with having my hand made brass Engineers ring professionally gold plated. I even suggested to them to nickel plate it first. They didn't and the gold plating wore off in a matter of months. Definitely nickel plate first. Good luck.

Stephen Beres
- Trumbull, Connecticut, USA



January 27, 2016

Q. Hi,

I have 2 choices,

1) Brass with 18K white gold plating (Coating: 0.03 mil)
2) 925 sterling silver with 18K white gold-plating (Not sure of coating thickness).

Please advise which will last longer. Been researching, and so confused about it.

OI HUI FANG
- Toapayoh, singapore


January 2016

Jewelry: Concepts and Technology
from Abe Books

or

A. Hi Oi. As noted earlier, trying to judge the longevity of a finish from the vendor's sales pap is nearly hopeless but I'll pick whatever is behind door "2" Door 1: 0.03 mil is .76 microns, which is probably reasonable today for costume jewelry. If it's a broach, it will probably last quite a long time; but if it's a ring, it probably won't last long (rings get a huge amount of wear).

Although you don't know the thickness of the gold plating on the sterling silver item, so it is impossible to predict it's longevity, the simple fact that it's made of sterling silver rather than brass, so is more costly, is a good indication that it's probably higher quality. :-)

Luck & Regards,

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



May 25, 2016

Q. If I want to gold plate spent brass ammunition, can I use the nickel plated brass and go from there or do I need to do something different?

Koby Sandusky
- Reading, Pennsylvania


June 2016

A. Hi Koby. As long as it remains "spent", nickel plating followed by gold plating sounds fine. Just don't try to fire it.

Regards,

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



October 19, 2016

Q. Really valuable information.

I would like to ask a question, if I would like to gold plate a brass ring as I understood nickel layer is necessary. But since this is a ring some people maybe allergic to nickel and would create problem.

In that case what would be the best practice?

Thank you

Jack Halis
- Philadelphia, Pennsylvania, USA


A. Hi Jack. Some would say to plate it with cobalt, but others suspect that cobalt is so similar to nickel that it's likely to have similar, just less publicized, issues. So white bronze plating is probably the best answer. There are several proprietary brands of white bronze plating processes available.

Regards,

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



December 7, 2016

Q. Ted,
I was wanting to gold plate brass, same as Koby. Thanks for the info.
You cautioned against firing such a round. Why? What are the consequences for such activity? Is it safety concerns or doing damage to a nice plating job?
Gale

Gale Kloesel
- Harper, Texas, USA


December 2016

A. Hi Gale. I'm no ammunition/firearms expert and I can't comment on potential safety issues with dimensional clearances, friction, cold welding in the barrel or clip, embrittlement of the casing and possibility of explosion, etc. I'm simply saying that gunpowder-charged bullets are lethal, precision engineered & carefully tested devices -- and I'd be very careful of willy-nilly alterations, especially amateur attempts at activating & electroplating because amateurs, almost by definition, often do a poor job and often don't understand all of the consequences of things.

Regards,

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


December 9, 2016

A. Gold plating brass is no problem and you definitely need a nickel undercoat.
Some brass cases come already nickel plated and there is a problem. Nickel passivates and has to be activated before it can be plated or adhesion will be very poor. It is much simpler to start with brass cases and nickel plate immediately with gold. This means nickel plate, rinse, gold plate not allowing the parts to dry out between.

I assume you are intending to plate the cases not the heads unless you are looking for low cost vampire ammo.

geoff smith
Geoff Smith
Hampshire, England



December 13, 2016

Q. Hello.

I have a briefcase with a scratch on the fitted brass lock. Where I've begun to sand down the scratched area with fine wet & dry sandpaper, the 'satin-gold lacquer' finish has been removed.

Is there a good method for touching up the gold lacquer finish or would I be best simply drilling out the lock and replacing it with a new one?

Grateful for any advice.

Many thanks,

Edward

Edward Murphy
leatherworker - Sussex, UK


December 2016

A. Hi Edward. Even if you know exactly what you've got, a perfect cosmetic repair is difficult. In this case I suspect, but don't know, that the lock had a thin layer of gold electroplating followed by some sort of clear lacquer. These finishes are usually mass-produced, with hundreds of parts simultaneously processed. I think the labor cost of re-plating and re-lacquering a single piece will be prohibitive, and that you will find it impractical to do in situ anyway.

Regards,

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



June 24, 2017

Q. Hello,
I found an old Coach coach and carriage metal cast decoration, perhaps from a Coach purse or suitcase. The original 18K gold finish has worn off in some areas and the back of the piece appears tarnished (dark brown tarnish/staining). I believe the main component is brass. How would I go about replating it? Would the original finish have to be stripped down/removed completely before replating?
Thanks,
Lisa

53424-1a 53424-1b 53424-1c

Lisa Hess
- Lutz, Florida USA



December 14, 2017

Q. I want to purchase a jewelry set but I am not sure if 14K Gold over brass is worth buying.

katrina carter
- carrollton, Georgia US


December 2017

A. Hi Katrina. Unfortunately, ad copy is designed to entice you to buy, not to technically inform you about the durability of the item. There are dozens of variables, and no practical way for a consumer to know the quality & longevity of the items they are buying except by relying on the integrity of the brand name and of the store.

Sorry, but I think that's just the way it is :-(

Regards,

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



January 10, 2018

Q. Hi, I'm trying to buy jewelry supplies from China and I would like to know which of the following descriptions is better to try (talking about quality and durability). I'm from Mexico and most of the vendors use only 1 or 2 descriptive words to name the quality like 22k or 10k Gold Plated

-Rack plating brass
-Golden Tone Brass
-Color keeping Brass
-plating
-Gold Plating Brass
-Brass
-Real Gold Plated

I can tell that the quality is directly related to the coverage between the plating and the material, but without knowing the material, which would be my best option?

Dulce Fimbres
- Sonora, Mexico



January 16, 2018

Q. Hi, may I know if I want to do 1 micron rose gold plating, between silver and bronze which material is durable to hold the rose gold plating?

Serena tan
- Kuala Lumpur, malaysia


January 17, 2018

A. Serena:
The durability of wear of your rose gold plate should be about the same over either since the plate is the same thickness. Rose gold already contains some copper so the substrate doesn't matter regarding tarnish.

Neil Bell
Red Sky Plating

supporting advertiser
Albuquerque, New Mexico
red sky banner ad



January 21, 2018

Q. My new gold plater (My amazing old one retired!) will not use nickel as an underplating for gold. He uses palladium ... is this effective for preventing the substrate (for me, usually copper, sometimes silver) from tarnishing the gold plating?
Also, he insists on a very high polish, or it will not look truly gold (My old player had no problems with the polish---he just warned that one would have gold plated scratches if not polished properly, but everything--the good, bad, and the ugly--always came out with a definite gold coating.

Katharine Wood
- - Bronx, New York, USA
  ^- Privately contact this inquirer -^


simultaneous January 23, 2018

A. Either nickel or palladium will stop diffusion from the under layer, however, nickel is irritating to some people's skin and that is why palladium is usually preferred.

robert probert
Robert H Probert
Robert H Probert Technical Services
supporting advertiser
Garner, North Carolina

Editor's note: Mr. Probert is the author of Aluminum How-To / Aluminio El Como


January 24, 2018

A. Hi Katharine,

I have seen palladium fail as a barrier, maybe because it was too thin. Regardless you should be able to get good results with gold plating over brushed and satin surface finishes as well as highly polished surfaces.

Neil Bell
Red Sky Plating
Albuquerque, New Mexico



February 19, 2018

Q. Hi, I am having jewelry made in Thailand that is 24k gold plated brass. I want it to be nickel and lead free so I understand that a different metal needs to be used as a barrier. I'm not sure what their plating process is (I have asked).

My questions are:

1. Is it worth it for the gold plating to be 3 microns? (i.e. is there much difference btwn 2-3 microns? Will it last longer etc?)
2. How thick/many microns should the barrier plating be?

Thank you!

Ruby W. [last name deleted for privacy by Editor]
- Sydney, NSW Australia


February 21, 2018

A. Hello Ruby, a palladium undercoating would be expensive, especially if you are dealing with plated jewelry. Check into white bronze as a barrier between the brass and gold. Six microns of the white bronze should be sufficient. Gold thickness on plated jewelry is normally very thin (10 microinches.) If you want quality, 2 micron gold thickness is the way to go as the finish will last longer than a flash plate. Use a hard acid gold which will give you better wear resistance. Keep in mind that with a barrier plate the gold color will be much different than it is with a brass substrate. Color matching will have to be done. With the added process and thicker gold deposit check your bottom line.

Mark Baker
Process Engineering - Phoenix, Arizona USA



The Jewelry Engravers Manual
by Hardy
from Abe Books

or

April 9, 2018

Q. I bought rose gold plated over brass necklace and had it engraved. Will this tarnish quickly or the brass born the plating? How can I clean it without taking the plating off?

Jennifer Allen
- Dekalb, Illinois


April 9, 2018

A. Hello, because brass is the underlying metal and there is no barrier plate (to prevent migration of the brass into the gold) it would actually depend on the thickness of the rose gold plate on how fast it will tarnish. Normally with this type of jewelry the gold plating is very thin. I like to use juice from real lemons. White vinegar works too. You can soak it first and then use a soft cloth to clean it better.

Mark Baker
Process Engineering - Phoenix, Arizona USA


April 9, 2018

Q. Thank you for responding. I decided to go with 14k rose gold filled. What does that mean exactly. What is the likelihood of tarnish and best way to clean?

Jennifer Allen[returning]
- Dekalb, Illinois


April 10, 2018

A. Hello Jennifer, you will be much better off with gold filled, as the gold layer is much thicker than electroplated gold. By standard, gold filled has to be a minimum of 5% gold by weight. The gold layer is bonded to the jewelry by heat and pressure. I wouldn't be concerned about tarnishing that much. A standard jewelry cleaner would be fine for normal cleaning.

Mark Baker
Process Engineering - Phoenix, Arizona USA



May 4, 2018

Q. Hello. I'm starting a new business and having some buckles made out of brass. The completed buckles will be cleaned and polished to a high finish. I intend to then get them plated in various plating finishes.

One will 18k yellow gold, one will be plated 18k rose gold, one 18k white gold, one will be black chrome and one will be just chrome. The plating will be 5 microns hard plated in order to give it that extra durability. I can go to 6 microns or even 7.

But after reading this thread, I didn't know a barrier plating would be required, because my supplier who will be making these never mentioned a barrier metal. So my question is:

is 5 micron hard plating enough to give it that longevity? or do I really need to add another plating barrier? With this buckle there is no skin contact; the only contact is with the leather belt.

Any help would be most appreciated.

Thanks.

Robert

Robert Thackery
- New York City, New York, USA


May 2018

A. Hi Robert. Chrome plating by itself is not a decorative finish; you need nickel-chrome -- in other words an underlayer of nickel plating anyway.

7 microns is, to my understanding, the thickness of gold used on the finest heirloom watches. Even 2-1/2 microns would be very high quality. I'd probably go with nickel plating followed by 2-1/2 microns of precious metal. But it's a bit more complicated than that: rose gold is usually just a thin "color" layer over a thicker layer of yellow or pink gold. White gold is usually not comprised of plating with white gold, but plating with rhodium. And chrome plating is usually substantially thinner than 2-1/2 microns. Good luck.

Regards,

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


simultaneous May 4, 2018

Q. Q. Hi Ted. Thank you so much for the quick response. I hope you don't mind, as I have a few more questions.

- Should Nickel plating be done just before the gold plating?
- Do you think that 2 1/2 microns would be thick enough to last at least 5 to 7 years? seeing that it will rub against a leather belt constantly and up to 10 to 12 hours a day.
I have the budget to go thicker if it means the plating will last bit longer and gives the "wow!" factor to the finish.

- Also, how can you actually tell how many microns has been applied? Is there a device or a machine I can buy to test (accurately) how thick the completed plating is? So I can hold to account a supplier if he bills me for 3 microns but only applies 1 or 2?

- The base metal of the buckle will be brass, is this the best metal to use? taking into account: cost, casting, and look and finish. Or do you recommend a different metal?

- I will be using silver too, as a more expensive option.

Rob.

Robert Thackery[returning]
- New York City, New York, USA


May 5, 2018

A. Hi Robert
Two thoughts.
A nickel barrier is so common that your supplier considers it part of the routine plating.
Do you have a means of verifying the gold thickness? And/or does your supplier certify the thickness. 5 microns of gold is an expensive spec to just take someone's word.
The kit (XRF) is expensive but without it neither you nor the supplier can guarantee the thickness.
You also need to consider that a belt buckle is a complex shape and the plating will not be of equal thickness all over.
Paying for a minimum thickness all over is expensive, as much of the part will be thicker and you will be paying for it.
I suggest that you get a sample plated and do a thickness survey and then decide what is the critical area that you need to specify.

geoff smith
Geoff Smith
Hampshire,
      England



May 2018

A. Hi again. As you can see, Geoff anticipated most of your questions.

Yes, the nickel plating must be done immediately before the gold plating. Vermeil jewelry is 2-1/2 microns of gold over sterling silver; you might be able to research how it holds up. X-ray Fluorescence thickness testing machines are awfully expensive, about the price of a new car, but you can probably find a lab to do the testing on a contract basis is need be. I believe brass is probably considered to be the most durable, plateable, and practical metal for such applications. Good luck.

Regards,

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


June 14, 2018

Q. I have a new van de graaf generator.its brushes are 2-four inch square brass screens. I would like to gold plate them. Can somebody point me to a plater or advice on best way to plate them. Thank you.

robo garrison
- mt.pleasant ,texas, usa
  ^- Privately contact this inquirer -^


June 18, 2018

Q. I have found some costume jewelry that is 18k yellow gold over bronze. The majority of the questions I have read are asking about gold plating over brass. I wanted to know if you believe the bronze to be better than brass and which one would last longer? There is no information on a plating barrier or the # of microns used. Thank you for any information!

Shannon Hulsey
- Valdosta, Georgia USA


June 2018

A. Hi Shannon. The longevity depends primarily on the gold thickness and plating barrier. So if you don't know that, unfortunately you can't make any predictions of life regardless of the substrate.

Regards,

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



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