This only works if the stripping solution has been used a bit
beforehand - to saturate it with gold. I never understood why the
gold reverse plated back out and the copper stayed behind? John
Burgess wanna take a crack at this?
I'm Not John Bugess, but I think I know the answer.. Different
metals will plate out of a solution at different voltages, this is a
result of different oxidation potentials. The metal with the lowest
E-zero value will plate out first is I recall corectly. And is also
the reason why Iron will go into solution deducing copper out of
solution giving that wonderful copper plating effect when one puts a
silver piece into pickle with iron binding wire attached.