Hi Davina,
While PMC does a great job at capturing texture, I wouldn’t say that
is it’s primary virtue. In fact, I’d give that description to the
fact that PMC allows us to work in ways that are similar to
metalworking, but unique. Among these is the creation of
three-dimensional forms, both for jewelry and functional objects.
All versions of PMC (Original, PMC+ and PMC3) offer three distinct
stages. First, the material feels and works like modeling clay. This
allows for three-dimensional modeling with the ease of a finger
touch. At this point, false starts can simply be wadded up and you
can try again. Who doesn’t like a “Do Over?” The second phase is
what potters call “leather hard” and what will be familiar to
jewelers as wax carving. I often rough out a form with my fingers,
then let it dry so I can work it with files, chisels, and sandpaper.
And finally, after firing, PMC is 100% fine silver, so it can be
worked with all the conventional metalsmithing techniques, including
filing, bending, soldering, sanding, tumbling, enameling,
electroplating, etc.
You asked some specific questions:
About working time - Original PMC has the longest working time, but
also the largest shrinkage rate. All versions can be misted with
water to restore their working properties.
Original PMC is somewhat brittle, about the same as cast fine
silver. The other versions are significantly denser and resemble high
quality castings.
As you say, PMC3 can be fired with a torch. Simply allow the piece
to dry thoroughly, then heat to a glowing red and hold for at least
one minute. You can see a video of this process at either of these
two sites:
http://pmcguild.com/gettingstarted/video_clips.html
Good luck,
Tim McCreight
Technical Consultant, PMC Guild
http://www.PMCguild.com