Cleaning Copper Contacts?

[Joe R.]

At 04:36 PM 10/3/05 -0700, you wrote:
>
>
>If the connector is gold plated, you should not need to clean them.  If you
>are having green, then the gold is a very thin plate,

  Not necessary. Gold is very porous and acids and the like penetrate it
easily and corrode the copper underneath and the corrosion products then
travel back through the gold and appear on the surface of the contact. It's
not uncommon to find gold plated contacts with nothing left but a thin
sheet of gold. All the copper was corroded away leaving nothing but the
gold. Corrosion like this is common on the HP calculators and it's what
happens when you plate gold directly over copper. The proper way to do it
is to plate nickel or other non-porous material over the copper and then
plate gold over that. The nickel will prevent the acids and oxygen from
penetrating the surface and corroding the copper. FWIW on OLD cars they
used to plate steel with copper, then nickel and then chrome plate over
that. Plating like that will easily last 40 years (speaking from experience).

   Joe

 or an amalgam of
>copper and gold ( and possibly other metals)  Have you tried a dremel tool
>with a dry polishing wheel - no solvent or compound?  Use it lightly.  This
>has worked wonders for me though it does take patience.
>