Firing sterling posts onto pmc

Jewelry Discussion
1

Hi,

I’ve used a few different firing settings and have not yet found
success firing ss posts onto pmc+ or pmc3. I also tried re-firing
the pieces at 600 for 45 minutes to harden the ss but it did not
harden at all. I had some success with that group when I twisted the
wire to harden it but wasn’t completely happy with the outcome. Any
other suggestions out there?

Thanks, Piper

2

I think that twisting the posts is the only hardening plan that will
actually work. I’d keep working at it until you resolve your
problems with it.

M’lou

3

Hi Piper,

I only solder sterling to pmc. I know some use depletion gilded
findings to fuse, but I find soldering is very easy. Just need to
neutralize well after pickling since the pmc will hold a bit of
pickle. I had heard that sterling, because of the oxidation, just
won’t make a good bond. So I just don’t bother. Perhaps if
mechanically captured, but…

Jack

4

Piper - You should solder the posts on to the fired metal clay. If
you want to embed the posts and fire the entire unit together, make
the post into an L-shape before embedding the leg of the L into the
clay. That will allow the post to grip tighter. As for work-hardening
the sterling post - twisting it with a pliers is the best method.

Sandra Graves
Artistic Endeavors with Wings of Light

5

I think your problem is that silver, unlike steel, will only soften
with heat, whether you quench it or not. If you try to drop the final
piece into a tumbler to work harden the posts, you risk breaking off
important parts of your PMC, so that won’t work, either.

Try this: Get silver tubing with an inside diameter about the same
size as your hard wire posts. Cut the tube to a millimeter or two
long, flare one end (or both ends) slightly to ensure it will hold
in the clay, and fire that into your PMC. When the piece has cooled,
push the post into the socket you have made, and just solder it in
place.

Steve
Gems Evermore

6

Metal Clay Jewel-ers tumble their jewelry all the time. It does work
harden the fine silver a bit and polishes it up very nicely if
that’s what they’re after. It doesn’t seem to me that you have much
experience with metal clay Steve. It’s a much hardier material than
you seem to think.

Sterling silver posts can easily be soldered directly to the metal
clay. The fired item just needs to be burnished first so that it
doesn’t soak up too much of the solder. I’ve been doing it for years
with no failed joins yet.

If you really don’t want to learn to solder you can buy the posts
that have a 1mm pad and embed them in PMC3 and fire no higher than
1250 for 45 minutes. Any higher than that and the sterling will
become brittle. Yes, the 45 minutes is a bit of overkill, but metal
clay when fired at low temperatures does better if left to soak for a
longer period of time.

There’s a soldering for metal clay video on the new Ganoksin
BenchTube site, another at PMCGuild.com and one on You Tube.
It’s not as intimidating as some new jewelry makers might think.

Lora