plating, anodizing, & finishing Q&As since 1989
Overmolding of gold plated ABS is causing discoloration and blistering
May 22, 2012
I have some ABS parts gold plated but we are finding that when these are then overmoulded into another ABS application the gold is bubbling and changing colour.
Any ideas would be welcome.
- Leicester UK
A. Hi Lesley.
Although I'm not really familiar with overmolding, this does sound like a very difficult application. Can you tell us approximately what temperature the ABS substrate or gold plating would see during the overmolding operation?
And when you say "gold plated", may we assume that this is a conventional decorative plating-on-plastics operation involving nickel plating with a flash of gold? As I say, I don't know much about this, but I do know that automotive manufacturers use a layer of copper plating below the nickel to help deal with thermal stresses from outdoor exposure. Does your plating process include a copper plating step? Thanks.
Ted Mooney, P.E.
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