Coloring Nickel Plating, like red or blue

A. Hi Matteo, we will try to advise Matt and Brandon of your posting, but e-mail addresses from 18 years ago very rarely work.

Metals are not red -- copper is orange-ish, brass & gold are yellow-ish, and most other metals including nickel are silver-ish. Copper & brass, and even silver, can generate salts that put beautiful patinas on them, but I know of no decorative patinas for nickel or nickel plating. But in addition to electrocoating or painting, you might consider powder coating, metal dyes, or coatings applied by PVD. Transparent lacquers can be tinted to translucent colors. Titanium is readily interference colored (a partial wavelength transparent coating of the right thickness to amplify/suppress specific colors) and stainless steel can be anodized similarly although with more difficulty and not as pleasing results, I suppose it's vaguely possible that marginal results could be obtained with nickel with enough experimentation.

I think the key to moving forward is for you to detail as carefully as you can exactly what you are trying to accomplish and on what sort of nickel plated parts because some processes like PVD may only be practical at large volume, some processes such as dyes and tinted lacquers may not be nearly durable enough, some may not be aesthetic enough, some like powder coating may be too thick, most will affect conductivity. A special potion you can just dip nickel into and turn it into a robust, attractive, red color sounds extremely unlikely to me ... a red-tinted translucent lacquer sounds the closet though. Luck & Regards,


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

A. Try expired US patent US6391181B1.Hope it helps and good luck!

A. Hello, Brandon. It may not be something you can do yourself, you might have to go to a jobshop for it, but Electrophoretic lacquer is commonly applied to nickel plating to simulate brass, and it is available in many other translucent colors as well. Good luck.

A. Hi, Brandon. Electrophoretic lacquer can be applied quite thin. Maybe 5-10 microns.

It has reasonable flexibility.

Regards,

Q. How is Electrophoretic Lacquer applied to jewellery.

"Electrocoating: a Guidebook for Finishers"
by Electrocoat Association
from Abe Books
or

Affil. Link
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A. Hi, Syed. Electrophoretic lacquering is done in an electrified tank, rather similar to electroplating. The electricity converts the components that are in the solution into lacquer on the surface of the parts.

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

A.
Copper Sulfate [affil link] 10-12 g/l
lead acetate [affil link] or lead nitrate 10-12 g/l
Sodium Thiosulfate [affil link] 100-180 g/l
rachel salt ^ ^{rochelle salt [affil link]} 15-20 g/l
temperature 18-25 °C
immersion: 5 min-yellow/ 7 min-brown/ 10 min-red/ 13 min-violet/ 17 min-blue/ 20 min-green.

I believe you should acid activate your parts. I tried this solution on newly deposited nickel and it was O.K .

Good luck

Q. Your nickel coloration process seems simple enough and most of the chemicals seem within my abilities to acquire but ...

I am wondering if anyone can recommend inexpensive US suppliers for this chemistry (online preferred) -- since my process will definitely be a trial run and I am on a student budget.

Also - what quality of finish are you obtaining? Your responses are very educational and much appreciated.

A. I got dark blue similar to gun blue, brightness as the base metal.

Good luck

Khair Shishani
aircraft maintenance - Al Ain, UAE

Q. What exactly do you mean by 'rachel salt' I have been unable to locate any for my purposes. Thanks.

A. I think the spelling in the USA is Rochelle salts. Jason Deible Plating - Grand Rapids, Michigan A. Try looking for Rochelle Salt. One source said that it was a sodium and potassium soluble tartrate. Did not find the precise formula and it is not in my Fisher catalogue. James Watts - Navarre, Florida A. Mr Brandon Hello, It is potassium sodium tartrate, you can prepare by mixing tartaric acid with sodium and potassium carbonate NaKC4H4O6. REGARDING OTHER SALT CAN BE PREPARED BY ADDING METALLIC LEAD TO NITRIC ACID AND COPPER ADDING TO SULFURIC ACID WITH A SMALL AMOUNT OF NITRIC (BE CAREFUL OF NITROGEN OXIDE FUMES, VENTILATION REQUIRED). REGARDING SODIUM THIOSULFATE IT IS A BIT COMPLICATED BUT YOU CAN TRY SODIUM SULFIDE OR POLYsulfide BY DISSOLVING SULFUR IN 200-400 G/L NaOH WHILE BOILING. Please be careful and ask help from a chemist and please read the material safety data sheets MSDS. Wish you good luck, God blessing. Please send feedback if possible! Khair Shishani aircraft maintenance - Al Ain, UAE

A. Lead-citfree recipe, for different colours:
copper acetate [affil link].......25 gms
Sodium Thiosulfate [affil link]......240 gms
Citric Acid [affil link]..............30 gms
16 °C temp, 20-300 min., according to Fishlock's Metal Coluring Handbook. Can be used on nickel or nickel plate.

A. Drew,
My first recommendation would be Cerakote.
It has a high abrasion resistance, comes in many colors, as with any coating preparation is key. Follow the instructions provided by Cerakote, or if you're not equipped to do it on your own, send it out to a coater to have it done.

--Rama

A. Hello Drew,
How about making the part undersize a hair to allow for paint?

Very interesting Expired patent:

A. Hi Shad. As brass and bronze plating became more expensive or more of a challenge because they are based on highly poisonous cyanide, it became commonplace to do a tinted electrophoretic lacquer (e-coat) on top of nickel plating to simulate the brass/bronze look. Lots of 'brass' lamps are actually tinted e-coat over nickel plating. Considering that the components are already nickel plated, it sounds like an ideal application.

Luck & Regards,

A. Hi again Shad. We don't post brand or sourcing recommendations (huh? why?) but proposed suppliers can contact you privately.
However, for a study conducted by finishing.com for IZA / ILZRO a few years ago, Molecular Technology Limited in Wolverhampton, England (acquired by Coventya, acquired in turn by Macdermid-Enthone), and PMA Photometals of Arizona (photometals.com) were generous enough to supply electrocoated samples for corrosion testing, so I'm happy to mention them as potential sources :-)

Luck & Regards,

A. Hi Matthew. I've seen socket wrench sets done that way, but they probably weren't done in the USA. If you are a hobbyist doing one or two alligator clips, regular wet paint may be as practical. But electrophoretic lacquer does sound good for alligator clips, as long as the teeth don't get coated since the lacquer is not conductive like nickel plating.

Luck & Regards,