chrome on plastic knobs?

[amptramp]

If I'm not mistaken, chrome plating on plastic usually starts with electroless nickle plating followed by chrome plating. Electroless nickle is a process that does not depend on external electricity and can be used on any surface - you could plate an apple if you wanted to. Then the nickle surface is used as an electrode for electroplating of chromium.

[jeyurkon]

Originally Posted by amptramp

If I'm not mistaken, chrome plating on plastic usually starts with electroless nickle plating followed by chrome plating. Electroless nickle is a process that does not depend on external electricity and can be used on any surface - you could plate an apple if you wanted to. Then the nickle surface is used as an electrode for electroplating of chromium.

That might be possible. Electroless nickel has improved over the years. Orginally the surface of plastic had to be activated by dipping it in a dilute acidified stannous chloride solution. Then it would be dipped in an electroless copper solution. Once that thin layer formed a thicker bright eletrolytic copper plating was done. Then depending on how bright it was they would either go directly to chrome plating it or polishing the copper first.

John