I am thinking about trying my hand at either PMC or Art Clay. I did
read the info on both in the archives comparing price, but I didn’t
see anything about the finished products. I hear that the resulting
metals are somewhat porous. Does one produce a denser metal or accept
soldering better than the other? Any other noticeable differences in
the finished product? I am also wondering about the Paragon SC-2
kiln that is often recommended. I caught a discussion somewhere where
many users complained about the door hinges coming loose and the door
not fitting right. Has anyone had any problems like this? What other
kilns work well for PMC? I have seen inexpensive kilns by JEN-KEN,
Satellite, and the Olympic Hotbox - any thoughts on these or the
Neycraft one? And if anyone has a used kiln that they want to sell
please feel free to contact me off list: jill@jjewelry.com Jillhttp://www.jjewelry.com
I am thinking about trying my hand at either PMC or Art Clay. I did read the info on both in the archives comparing price, but I didn't see anything about the finished products. I hear that the resulting metals are somewhat porous. Does one produce a denser metal or accept soldering better than the other? Any other noticeable differences in the finished product?
When I was considering the two a while back, I noticed that the PMC
had a MUCH higher required fire temp than the Art Clay, though I’ve
heard that’s been brought down. You might want to check that out.
Finished pieces are porous because the non-silver filler ‘cinters’
out and leaves micro voids. I’ve read that it takes more solder due to
the porosity, and you might need to burnish areas to get a good bright
finish there.
Donna Hawk
Dallas, TX
Greetings- I work with PMC exclusively so I cannot speak for Art Clay,
however I have extensive experience with the properties of PMC. Yes,
the end product is more porous as a result of the silver having been
mixed with the binder and water which burns out. Standard PMC is the
least dense but PMC Plus is a more dense version, each having their
pros and cons. Standard PMC is softer and a bit easier to work with,
takes impressions incredibly well, great crisp details on miniature
levels are possible…PMC Plus is denser, therefore stronger, shrinks
less and has the added feature of being able to be “rapid fired” and
at varying temperatures. This gives the flexibility of being able to
include sterling silver and/or dichroic glass to your finished pieces.
Because of PMC’s porosity, it is more difficult to solder, the solder
tends to be readily absorbed. It can be done however simply by
altering your technique a bit. The denser PMC Plus is easier to
solder as you might imagine. For more general and specific technical
I suggest you visit the official guild website at
http://www.pmclay.com As for the kiln, I use the SC-2 and have had not
a lick of trouble, I teach classes and it is a real workhorse. Have
kiln, will travel!
Beverly
SilverGrove Studio
The trick to soldering fired PMC is to burnish the area to be
soldered as much as possible. keep the area very clean and work
quickly with your torch. Good luck and Have fun!
I've read that it takes more solder due to the porosity, and you might need to burnish areas to get a good bright finish there.
This is very true! The first time I ever tried to solder a bail to
one of my PMC pendants I did not heavily burnish the surface. The PMC
acted like a sponge. Rather than flow the solder was absorbed by the
PMC. I’ve found I have much better luck soldering to PMC when I
heavily burnish the area to be soldered and use easy solder. The
temperatures required for hard solder seem to make the PMC more
absorbent.
Shane
The trick to soldering PMC is to remove the heat as soon as the
solder starts to flow. If one contiues to heat the piece, the PMC
will be over-heated and start to crumble (after sucking up all the
solder that one started with.) : )
The info so far on soldering PMC is all good, but I think I can
expand it a little. I have found that what works best for me is to
burnish with a hammer handpiece in the flexshaft. It really does a
good job of compressing the PMC without changing the other side. As
an aside–before I figured this out, I have actually had a piece
absorb so much solder that it literally dripped out the other side
of a thin piece, without soldering the finding on. Beware
overheating! Easy to do, since PMC doesn’t melt all that readily. As
for soldering technique, it is important to understand that you
cannot wait for the solder to really flow the way you normally would.
You need to use much larger pieces than usual, place them
strategically, and heat only until the solder slumps. If it runs,
chances are it will absorb. This is less true with PMC+, but it still
is not like “normal” silver. The resulting connections are not as
neat and pretty, unless you do a lot of clean-up filing. To touch on
the comparison with Art Clay-- I used it several years ago, and, at
the time, felt that the resulting pieces were pretty much
indistinguishable from PMC. I used it at first because I got a better
price break from --Swest, was it? Then I couldn’t get it anymore, and
Rio is so organized, and improved their price break, so I haven’t
used it in years.
Dear Dawn, I have a question - I rolled 2 pieces of clay and created
a curved design and baked it, but when I went to slip wire through a
hole in the curve they came apart . What could I use to adhere the
already baked pc’s together again.
Thank You,
Nancy G.
Nancy, I have been “repairing” pmc items with a slip made out of pmc
plus (think ceramics, thinned clay, gooey like cake batter). Add the
pmc plus slip to the area to be attached with a fine tool, or brush,
let dry, it might need a second coat as it shrinks as it drys. Then
fire according to the “plus” directions. This is a great way to add
bits and pieces after the first firing. I havent tried it yet but I
understand gold overlays can be added this way too. I am new to the
pmc world, adding it to my metalsmithing techniques and having a lot
of fun with it! Good luck, Jenn