A bit of misappeared in another posting to Orchid Forum
Re: liver of sulphur and Precious Metal Clay and I want to offer the
correct LOS works beautifully with PMC and other metal
clays (as well as with fine silver in general). I include patinating
with LOS in all my workshops (check out my teaching schedule on
<pmcguild.com> General Classes listings).
After removing the metal from the kiln and cooling it, first, brass
brush the metal with a drop of liquid dishwashing detergent, to
brighten the surface. With PMC one should burnish the metal (via
tumbling with steel shot… the easiest method) before patinating
with LOS to prevent future gradual intensifying of the patina due to
the low density of the sintered metal. At this point you might want
to polish/finish the surface completely. Then go on to patina with
Use a slightly weaker LOS solution than one would use for sterling,
using a warm solution and warming the metal itself under hot running
water. Be sure to actively ventilate (a fan, not just an open
window, that moves the air away from your nose) the area.
Dip the metal in the solution, rinse, dip, etc., alternating a dip
in the solution with a rinse under hot running water until the
desired patina coloration has been reached. This prevents an abrupt
darkening of the metal and allows one to have some control over the
Wash off the metal when the desired color has been achieved. I
occasionally will rinse the metal in my ultrasound with a few drops
of soapy household ammonia for just a minute or two.
One can achieve, using this method, all the range of colors possible
with LOS in addition to deep gray with Precious Metal Clay. After
patinating, the metal can be wiped with a bit of olive oil and fine
grade pumice on a 100% cotton rag to emphasize the raised areas, or
may be brass brushed or tumbled again with a resulting all-over
Hope this helps to dispel any myths about using Liver of Sulphur to
patinate metal clays.
For more on using Precious Metal Clay, check out
<pmcguild.com> and join the PMC Guild to receive the newsletter,
Studio PMC, a useful and juicy periodical containing updates on
techniques and a gallery section in each issue.