Topic: American pill box intaglio lid

[dirk.]

Kristi, you´re right, the gold itself is inert. but i assumed the box isn´t massive
but either fire gilded or plated. therefor we have to consider the reaction of two
different metals. i´m recalling from school days: wherever two different metals are
brought together they react due to their potential gradient. this effect is facilitated
by acid or any other electrolytic solution.
in short - the more noble metal brings the less to produce oxyde, which makes the
plating flake off. this effect is of course by far more obvious on e.g. chrome plated
objects.
clockmakers wear gloves when they have to touch gilded bronze, too. i was just
offering the most secure handling.

[krsilber]

Sorry, didn't mean to disagree.  It was offered more as an aside than anything, since the piece is obviously of other materials besides gold.

I would imagine that in the case of gold plating (at least with 24K) the concern would be abrasion to the gold and corrosion to areas that weren't completely gold covered.  The corrosion might also creep under the gold.  "wherever two different metals are brought together they react due to their potential gradient. "  What do you mean by "react" here?  As I understand it, in electroplating metal ions are reduced and bond to the substrate by the shared electron.  Oxides (like rust) form when oxygen bonds to the metal, helped by water or some other solute. 

We're probably saying the same thing, just in different ways!

[dirk.]

We're probably saying the same thing, just in different ways!

The corrosion might also creep under the gold.

agreed! that´s what i meant to express...