[CR]Zinc Plating that's Gold

Date: Thu, 12 Jun 2003 15:08:45 -0400
From: kurtsperry@netscape.net (Kurt Sperry)
To: classicrendezvous@bikelist.org
Subject: [CR]Zinc Plating that's Gold

That iridescent "gold" finish is a zinc dichromate dip treatment on a zinc or cadmium plate. I doubt that Brembo would use that finish on their calipers as they they are Al-alloy, and the dichromate finish is an anti-corrosive treatment specifically for steel. One gold finish used on Al-alloy (and steel too) is titanium nitride (TiN), although it is usually specified for its tribological (basically wear) rather than anti-corrosive properties. I had always assumed that the gold finish on Brembo calipers was either gold-dyed oxide anodizing or paint. The iridescent dichromate looks similar to me whether it is done over zinc or cad plating.

Kurt Sperry in Bellingham WA

Wayne Davidson wrote:
> Hi all, I am tring to remember the electroplating process that is done
> with zinc and ebds up a goldish colour. I remeber reading about brembo
> using the process for its brake calipers. It's not cadium as its
> sometimes a greenish colour, I know its a little OT, but i'm sure some of
> you rebuilders may find it usefull one day...

Automotive nuts and bolts have a "Gold Iridite" finish and look goldish.

Chuck Schmidt