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Gold plating and electrophoretic lacquering of brass costume/imitation jewelry

Q. I would like to apply the Electrophoretic lacquer coating on my intricate brass pieces which I use as patterns for the castings. So I would like to know the required thickness of the lacquer coating. The thickness of the coating should not affect the dimensions of the cast pieces. And also regarding the hardness and toughness of the coated metal?

Sajeesh [last name deleted for privacy by Editor]
imitation jewellery - Mumbai, Maharashtra, India
2005

Q. Hi,

I make jewelry from brass and then I do a 6-step electroplating process: boil in ultrasonic solution, acid wash, heavy copper plating, brightening copper solution, then nickel plating, and finally gold plating with AuCn. After each process the brass is properly washed in tap water, mild solution of H2SO4 and then distilled water in between tanks.

I haven't achieved the quality that lasts as long as I would want.

Can I use anything like lacquer to coat it to keep away moisture and air and still keep the shiny gold finish look?

Emeka Ohaejesi
product designer - Bangkok, Thailand
2007

A. Hi Sajeesh and Emeka. There are clear spray lacquers and electrophoretic coatings available, but then your jewelry is no longer 'real'. Gold plating should not tarnish, and it will last in proportion to its thickness, although it may be possible to apply a harder and more wear-resistant gold formulation.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

Q. . What makes up a more resistant gold solution?
What else do I add to the AuCn solution to maximize durability?

Emeka Ohaejesi
- Bangkok, Thailand
2007

A. Emeka,
Precious metal suppliers for electroplating can help you get the desired color and thickness when you buy their products. If you insist on using a free cyanide based solution, there are also liquid alloys such as copper, silver and nickel that are proprietary. The alloys for acid gold and cyanide based baths can be adjusted for color and hardness. I like the hard acid golds for their ease of control.

Mark Baker
Process Engineer - Syracuse, New York
2007

A. There are alloying metals, such as cobalt, sometimes added to gold to make a harder gold finish. You can get some general information about the formulation of plating solutions from such books as the Metal Finishing Guidebook and the Electroplating Engineering Handbook [on AbeBooks or eBay or Amazon] . But this site is targeted more towards industrial metal finishing and the application of plating solutions than formulation of plating solutions. You can purchase proprietary plating solutions where decades of development and testing towards optimization have already been done if you wish. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

Q. I'm Sameer and work in jewellery making.I would like to know how to make perfect plating because I usually use potassium cyanide dissolve in water + 2 batteries of 1.5 v and 2 grams of pure gold to make an anode. My plating is sometimes black. What is my mistake? Does pH play a role in it? Can you tell me what is the perfect ratio of potassium cyanide and water? Thanks.

Sameer H.M
jewellery making - Mauritius
2007

February 20, 2008

Q. Hi,

I'm a jewelry designer (beginner), and I want to make my jewelry from brass and then gold plating.

I can't use nickel undercoat to get a hard electroplating because I'm exporting my jewelry to Europe where the nickel is forbidden. The company which does the electroplating for me will use first copper then white bronze-like undercoat before the gold.

I will like to use the minimum microns for the gold because my jewelry has a big volume, and the gold is very expensive, but I need a good and resistant quality because my jewelry is destined to high quality fashion customers .

I m thinking of using only 1 micron of gold then an electrophoretic coat ("clearlyte"), but I've just read in this website that the jewelry won't look real anymore. What does that mean? Does it mean that it look like plastic jewelry?

I'm scared of losing the real look of gold and getting a cheap and ugly finishing.

unfortunately, I can't try this product because they don t sell it in Indonesia, and if I order it, I have to buy a minimum quantity (which is huge!) .

The supplier of "Clearlyte" told me that they have only one shiny finish.

Please can you help me, it's very difficult to get this kind of information in Indonesia. Is "Clearlyte" used only for cheap jewelry? How does the finishing look?

Thank you so much in advance for your time.

Yelena

Yelena Gazikalovic
- Bali, Indonesia

High End Gold Plated Belt Buckle Production

September 2, 2016

Q. Hi,

I'm looking to start a high-end designer leather belt range and the current belt buckle are made from brass then gold plating.

Nickel is used as an undercoat to get a hard electroplating and stop the brass for migrating before gold plating. The gold plating is done to about 3 microns on the belt buckle.

The question is, how long will it take for a 3 micron gold plate on a belt buckle to wear out (given if it's used every day). I need a good and resistant quality because my belts are destined to high quality fashion customers.

Secondly, do I have to do anything (clear-coat or an extra plating) to the gold plated buckle to give it more rigidity but I wouldn't want to lose the real look of gold on the buckles.

Please can you help me as it has been a challenge for me to get this information.

Thank you so much in advance for your time.

Regards
Chuk

Chuk Enweluzo
- Bristol, United Kingdom

A. Hi Chuk. 3 microns is exceptional quality and should last years in most situations. While it's hard to say exactly what the wear situation is where the prong grinds against the frame, that's the one spot that isn't visible when worn anyway. I would be surprised if you had any trouble or complaints even after many years (remember though, that I'm not a belt designer, and other readers aren't likely to be either).

If the volume were high you could have the buckles PVD coated with TiN before the gold plating. For lower volumes you could apply some sort of clearcoat, but I don't think it's necessary, and it's nice to be able to say your gold plating stands on its own. Good luck.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 2016

A. Gold is soft, so I would guess that you need to use something like 10k vs pure gold. A lifetime ago, I had read about "hard " gold. You might want to look into that also.

James Watts
- Navarre, Florida
September 2, 2016

September 2, 2016

Q. Hi,

Thanks for getting back to me with that assurance for my product.

I have got two more questions, hope you would be able to help again!

1 - after the buckle is gold plated, is there any other finish/process required to give it a professional finish.

2 - What process can be used to remove fine marks on the gold plated buckle which appears when cleaned with a cloth or can that be minimised by cleaning it with any substance which wouldn't affect the gold plate.

Regards
Chuk

Chuk Enweluzo [returning]
- Bristol, United Kingdom

A. Hello Chuck, Ted and James gave excellent info in their comments. A hard acid gold would be the way to go. These gold plating solutions are normally alloyed with nickel or cobalt. As James mentioned you want the gold alloyed to get a 12 or 10 kt finish. You would have to like the colour however. To gain your business, precious metal plating suppliers could plate a few buckles in their lab for you. This way you would know what gold plating bath to use. I am not permitted to name a good supplier on this site but I'm pretty sure they are one of the sponsors. The gold thickness you describe will give you a nice quality product. I have seen clear coats on gold wear away after a few years. Good luck with your new venture!

Mark Baker
Process Engineer - Phoenix Arizona
September 2, 2016

A. Hi Chuck
A belt buckle is a very high wear item in jewelry terms.
Decorative golds are soft and will rapidly wear. I would recommend one of the hard acid gold plating solutions used for heavy wear on electronic connectors. These contain a small amount of nickel or cobalt and still have a very acceptable gold colour. They are regularly plated to 5 microns over nickel.
The usual plating suppliers will advise you; Metalor, Macdermid, etc.
Clear coating over the gold will wear through in areas and look patchy.
It would be very expensive to set up the process for just the one item. The same supply houses can advise you of someone in your area who can do the job.

Geoff Smith
Hampshire, England
September 3, 2016

Q. Hi

Urgent help needed please!

After gold plating buckles made from brass material, do I have to bake the buckles?
I am confused as I have seen someone state that on a different site.

Regards
Chuk

Chuk Enweluzo [returning]
- Bristol, United Kingdom
September 4, 2016

A. Hi again. Gold plating per se does not require baking. Some possible reasons for confusion or contrary opinions, however, could include: 1) the rinsing water must be dried, and often this is done at heat; 2) sometimes plated parts are heated as a QA measure to make sure the plating doesn't blister; 3) some clearcoats are baked for curing.

Some excellent info from Mark Baker and Geoff Smith "crossed in the mail".

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 2016

A. Hi Chuk. You may have seen a post about hydrogen embrittlement and baking after plating to fix this problem. This is usually only a problem with high strength steel items. We are baking some steel fountain pen components after we gold plate them but we haven't seen this problem with bronze, brass or other metals.

Neil Bell
Red Sky Plating

Albuquerque, New Mexico

September 5, 2016

Q. Hi.
Dear sir, I am a brass buttons manufacturer. It is made from brass metal strips. I am doing acid copper and brass plating; after it, water based lacquer for protective layer. But sir, it is changing colour very quickly. I want minimum one year plating life; my product is very small so cannot hang this goods for electrophoretic lacquer. Please suggest how I can get one year life of plating. I want bright gold colour, but can't do gold plating because cost will be high
Thanks, looking forward for your reply.

Saurabh goyal
Khushi traders - FIROZABAD, Uttar Pradesh, India
June 20, 2018

A. Hi Saurabh. Unfortunately, you haven't told us how thick the copper and brass plating layers are, and we don't know what you mean by "changing color very quickly". Is it getting blackened areas which could be cyanide bleedout, or is the lacquer turning yellow, or is the brass losing its shine and becoming dull?

adv.

"Clearcoats/Lacquers for Brass from G.J. Nikolas"

Please send photos of the failing parts next to good parts so we can see the color change. Meanwhile, if we assume the brass is getting dull, I think a water based lacquer is probably not up to the task. Please consider dipping in a dilute sodium benzotriazole [on eBay or Amazon] rinse, and then spraying with a solvent based lacquer. Good luck.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
June 2018

Q. Hi..
Thank you dear sir for your reply. Actually sir I want to do electrophoretic lacquer dye gold for very good results but my product is very small as 3mm, 4mm, 6mm and quantity is 200kg every day. So cannot hang every piece for electric currant, please suggest me which kind of plating method or which kind of equipment we can do electrophoretic lacquer dye gold on very small parts. I want one year life of plating.

Saurabh goyal [returning]
- FIROZABAD, Uttar Pradesh India
July 9, 2018

Q. Hello Everyone. Jewelry making is my passion. Problem which I am facing is how can I seal copper jewelry? I handcraft them, need suggestion. Currently in India.

The normal lacquer spray will wear off within a month. Also after polishing, what should I do. How to coat or finish it. I need to sell them but want to give customers quality & satisfaction. Really confused.

Poornima Sharma
- Delhi, New Delhi, India
June 7, 2018

Q. I am an imitation jewelry craftsman. I have trouble finding a gold color substitute other than using a layer of pure gold. Are there other ways beside using gold base material?

Ilham Fiqri
Plating - Indonesia
August 24, 2018

A. Hi Ilham. The most convincing alternative is probably titanium nitride coatings applied in a PVD chamber, but the capital cost is probably out of reach for craftsmen. A gold colored CED coating is possible but is only generally somewhat gold colored; no one would mistake it for gold plating. In letter 37526 Geoff Smith tells us about some alloys intended to look like gold including Pinchbeck Alloy, Dutch Metal, and Nordic Gold.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 2018

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