Summary for satin nickel plating Discussion
satin nickel plating is the leading guess in this thread, but AF Kenton cautions that a verbal description is not enough to identify the finish with confidence. Tomasz Taubert describes a milky-white satin surface on aluminum die casting that is electrically conductive, about 40–45 µm thick, scratches easily, and shows bright metallic marks where abraded or buffed. Kenton first suggests satin nickel plating, then later says Jim’s recommendation to use XRF testing is probably more productive than guessing. He also outlines a likely process if it is nickel on aluminum: pretreat, zincate, alkaline electroless nickel strike, and then electroplate with something. Tomasz asks whether such a finish would be chemical or electrochemical and whether it could be applied uniformly to complex finned parts; the thread does not give a definitive cost or process answer, only a probable plating sequence and the advice to verify by analysis.
Q. We are an electronics OEM and have here a sample of aluminum die casting with a surface finish (not paint) that we like but were not able to identify with the help of local shops. The finish is milky-white satin. It produces metallic sheen when scratched – and it does scratch easily. The surface is electrically conductive and the thickness meter shows 40-45 µm. Any ideas what it could be?
Tomasz Taubert
– Gilbert, Arizona
A. Hi. I’ll play. Satin nickel plating?
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
October 29, 2012
A. Got a question for you. Is there any other pattern or marks on parts?
AF Kenton
retired business owner – Hatboro, Pennsylvania
November 1, 2012
A. Try to find someone with an x-ray fluorescence device. If the coating is not aluminum, it should be able to tell you its composition in a few seconds, without having to destroy the part.
Jim Treglio – scwineryreview.com
PVD Consultant & Wine Lover
San Diego, California
November 1, 2012
Jim,
Thank you for the XRF test idea.
Tomasz Taubert
– Gilbert, Arizona, USA
November 5, 2012
Q. The surface is relatively uniform and it masks or tones down some of the casting skin coloristic unevenness. This is why I like it. What is most visible on my sample are post-finish scratches (either from handling or made while investigating the nature of the finish) and brightened areas buffed in handling. All the markings have shiny metallic character — scratches to a higher degree, buffing at a lower. The sample looks also a bit like a fresh silver part with matte finish.
If the finish is a satin nickel over aluminum, how difficult and costly is this finish? Is that a chemical or electrochemical process? My target parts are quite complex in shape, pretty much a heat sink with fins and I am concerned about getting a uniform finish between the fins.
Tomasz Taubert
– Gilbert, Arizona, USA
A. Hi. Jim is probably right that doing an XRF test to determine what it is will prove more productive than guessing based on verbal descriptions.
The overall process is probably: pretreat, zincate, alkaline electroless nickel strike, and then electroplate with something.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
November 6, 2012
A. Hmmmm. You mentioned matte finish. That is typical of a mass finishing system using plastic deburring media. I remember a couple of heat sink companies using mass finishing. It is a wet process that can produce results down to 12 RMS but 14-16 is more common
AF Kenton
retired business owner – Hatboro, Pennsylvania
November 7, 2012