Color of red gold is not right

Letter# 136

Coloring of red gold is not right

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I have a question regarding the colors of gold plating. I got a sample from a customer of a bracelet that was gold brush plated. The color to me was very yellow, almost fluorescent it was so bright. I sent the bracelet to see if I could obtain a solution so I could plate that color. The supplier said it was red gold and had a copper additive. I have rose gold here which has copper, when it is plated, it looks like there is no gold in it, just red copper. We have a normal cobalt hardened and cyanide gold we use for brush plating that has a what I call a reddish cast to it that is fairly deep in color. The baths we are using are acid cyanide. Has anyone out there got experience with gold colors that could help me or perhaps point me to somewhere I can get help. The colors I see seem not to coincide with what the gold is called (red,rose,etc.).

GoldTouch

Gold coloring is a treasured art form that I can't pretend expertise or experience in, so I hope you can get an authoritative answer from someone else here. But in the meanwhile, Alfred Weisberg's handbook article on the subject, which can be found in both the Metal Finishing Guidebook and the Products Finishing [link is to product info at Amazon] Directory, gives charts of the various colors and the percentage of copper and nickel, etc., used to obtain them.

Ted Mooney, P.E.
finishing.com
Brick, New Jersey

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Hi,

I think this problem is of more copper content in the bath with more than what is recommended. So please reduce copper content in your bath; meanwhile maybe there may be a cause if pH is more this problem arises. Check the pH of your bath and then if bath contains organic contamination that also may be one of the problems.

VADLAMANI SREENIVAS
- Hyderabad, Andhra Pradesh, India

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