Gilding

Jewelry Discussion
1

I’m puzzled! I’m working on an antique watch made around 1820 a the
moment and it has automata on the front - little men who ‘strike’
dummy bells when the watch strikes. These figures appear to be cast
or stamped out of silver and are gilded in several colours of gold. I
assume that, at that time, the only kind of gilding done would be
mercurial ‘fire’ gilding but, from what I have read, this is normally
only possible with fine gold. I’m intrigued to know how these wily
old artisans may have achieved the effects they have and I’d be
interested to try to reproduce it myself (with all the appropriate
safety measures!!) I have put pictures of a couple of the parts on my
website at:

http://www.watchman.dsl.pipex.com/temp/automaton/automaton-bells-web.jpg
http://www.watchman.dsl.pipex.com/temp/automaton/automaton-right-web.jpg
http://www.watchman.dsl.pipex.com/temp/automaton/automaton-right-back-web.jpg

The ‘man’ part has a total height of around 3/4" (20mm) Any ideas??

Best Wishes,
Ian
Ian W. Wright
Sheffield UK

2 
   . . . . These figures appear to be cast or stamped out of silver
and are gilded in several colours of gold. I assume that, at that
time, the only kind of gilding done would be mercurial 'fire'
gilding Ian W. Wright

Hello Ian; I get a lot of “estate” jewelry to repair, and I’ve seen
work done in different colors of gold that I believe was probably
done by means of depletion gilding. Check out Brepohl’s text on this
technique. One can change the surface of the gold by using different
etchants to remove different components of the alloy, i.e., ferric
chloride to remove the copper and leave a green color, ferric nitrate
to remove the silver and leave a rose color, etc. Fire guilding has
a distinct “pebble” finish in most cases and is recognizable. The
depletion method can be made to be quite durable by repeated etching
and burnishing though.

David L. Huffman