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Letter 15006 Why does gold plating tarnish?++ I have observed that the gold plating has some darkening areas over the nickel plated copper base material. What causes this effect? We all know that gold is a very inert metal & does not corrode or rust. In this case, it should not tarnish. Under what circumstances or condition does this problem arises? Your advice is greatly appreciated. Thank you Maung San Zaw
++ Hi, Gold as such will not tarnish. It is inert. The tarnish like appearance is due to underlying surface getting corroded or oxidized. If the thickness of gold is not adequate and if the coating is porous, the corrosion taking place in the underlying surface may seem like tarnish. Ensure that you have adequate thickness build up of gold, to put an end to your problem. Good luck ... Karthik
++ Hi, If you have nickel plating as a finish to plate gold onto it will normally not tarnishing even if you only deposit 0,1 micron of gold. This could mean that the gold plating solution has contamination, which tarnished. If you have nickel-free plating and plate gold onto copper or bronze the tarnish would come from the base if the gold plating is too thin to form a uniform layer without pores. Good luck and all the best, Trudy Kastner
++ Need to know about colouring gold (pink, green, red etc.) Would anyone mind answering this? Need information about the process of colouring gold. Thank You, Jayalakshmi. S.
++ In general, gold coloring is done by alloying other metals into the plating. You will find some general info about this subject in the Metal Finishing Guidebook. But at this point you will find the subject to be within the domain of art rather than science, as the exact formulas are closely held, and I know of no articles in the literature exactly quantifying the coloration as a function of the alloying.
March 25, 2007 Why does pink gold plating tarnish? Now I have a problem about
plating. Silver ring plated with pink gold. It is beautiful. but when
I show it only 2 weeks, it is tarnishing. I think that because of my
sweat or pink gold plating process or chemical of pink gold
plating. Jane
HI vanessa zeena
Dear Reader: please choose what you want to do.
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