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

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


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,

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
finishing.com
Brick, 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
    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,

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
finishing.com
Brick, 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 scientifically inform you, but to induce you to buy it. 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. Good quality costume jewelry should probably have one micron of gold plating on it. Good luck.

Regards,

pic of Ted Mooney Teds signature
Ted Mooney, P.E. RET
finishing.com
Brick, New Jersey

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