Yellow shade in decorative chrome plating

A. Hi Freddrick. Chrome plating is considered blue-white compared to the yellow-white of nickel plating. It should not be deposited directly onto electroless nickel but onto bright nickel.

May we ask how you know you have 0.2 to 0.5 microns of chrome on the parts?

Is it possible that you are calculating this thickness based on immersion time rather than actually measuring it? Something important to remember is that chrome will not deposit at all if the current density is too low.

Luck & Regards,


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

A. We misspoke if we said or implied that chrome is clear. It is not; it is metallic in color. It is a very slightly blueish white metallic color, but definitely metallic rather than blue. The color difference between the very slightly yellowish color of nickel and the very slightly blueish color of chrome and the whitish color of silver is subtle, but becomes obvious when parts are next to each other in good light.

Copper is often "hard chrome" plated, which means a very heavy coating of chrome; and in this case the article looks a lot like bright cold finished steel. In decorative chromium plating the thickness is usually inconsistent, and if a very thin coating of chrome, 10-20 millionths of an inch, typical of decorative nickel-chrome plating, were put directly onto copper it would probably just look discolored and crummy because the copper might partially show through in some areas and not in others.

Please help us help you by telling us what your actual situation is, so we don't have to answer with ifs-ands-&-buts which may still miss the heart of your issue. Thanks!

Regards,

A. Most bright work for the last many decades has been nickel-chrome plated, Robert. Look at trucks or Harleys for an example of this. This finish is produced by nickel plating and then adding a very thin topcoat of chromium plating. The chromium is valuable for resisting corrosion in this difficult exterior service, and the chrome deters the nickel from tarnishing while it adds a bluish cast.

If the chrome is omitted (which is probably okay for interior service, less okay for tough exposures), the color is more yellowish -- indeed warmer. We are not talking gold or brass color, just a faint cast to the metallic look. Practioners may describe silver as "whitish", nickel as "yellowish" , and chrome as "bluish". Nickel tarnishes (it grows yellower over time if the tarnish is not polished away). Times change and public tastes change, but nickel is "in" these days.

Although electrodepositing alloys like brass is possible, and various tints are possible in gold plating, in general the color of electroplating is not controlled by alloying; rather the item is either nickel, chrome, or silver colored.

Electroless plating is, in general, much costlier than electroplating and applied only for its functional properties, not its decorative value.

This site is possible through the support of a number of plating shops, including some in your area, which you can see in our Directory of Jobshops. We can't also ask them to bear the cost of posting testimonials to their competitors who pay nothing, so we can't print recommendations of specific shops here. Good luck.

A. If you are looking for warm silver tones you might be looking as Ted said for nickel + chrome. If you are looking for silverish finish nickel alone can provide it, most shops today can plate a very white nickel. It is necessary to top coat the nickel with either lacquer or clear powder coat. Other finishes popular with the furniture and hardware manufacturers are satin nickel (has a stainless steel type look), brushed nickel (similar to satin but with "brush marks") various "antiqued" nickel and brass colorations, etc. I suggest you talk to someone in you area who specializes in refinishing.

A. Hi, Adesh. It seems you didn't quite understand Geoff's response: 1 kg of barium carbonate will remove 1/2 kg of H2SO4.

Good luck!

Regards,