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What interlayer makes plated plastic so corrosion resistant?

Have experienced some exceptional decorative finishes on Plastic and critically deteriorated steel parts. Am interested to learn what is used for an interlayer between different types of plastic and copper layer?

Al Doerbecker
Plating Shop Employee - Bellmore, New York
April 28, 2011

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April 29, 2011

Hi, Al.

There is no miracle interlayer that prevents plated plastic from corroding. Rather, if I'm understanding you, its corrosion resistance is due to two factors:
1. There is no underlying steel to corrode. Remember that steel is anodic to many plating materials like copper, nickel, and chrome; once there is any porosity, the plating rapidly accelerates the rusting of the steel.
2. OEM automotive parts, if that's what you are referring to, have very tight quality control and an exceptionally robust plating specification consisting of at least electroless plating, followed by heavy copper plating (actually for thermal resistance rather than corrosion prevention), followed by at least 2 layers of nickel plating, often more, carefully controlled for electrochemical activity by STEP testing, followed by excellent chrome plating.

Regards,

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