Back to Ganoksin | FAQ | Contact

PMC in general


#1

Hi there!
I have been reading about PMC and have seen some of the pieces only
as images on the net. I have some questions regarding the jewellery
made from PMC :

Do the finished jewellery pieces have porosity?
How well has this jewellery been accepted by the consumers?
Is it cost effective?

I am in India and would appreciate on where I can learn
to work with this material.

Thanks in advance.
Hema


#2
       Do the finished jewellery pieces have porosity> 

No. PMC, fired at 1650 for 2 hours, has the same density of cast
fine silver.

       How well has this jewellery been accepted by the consumers
Is it cost effective? 

Yes, and yes.

       I am in India and would appreciate on where I
can learn to work with this material? 

check http://www.PMCGuild.com, they list some itnernational options.

Elaine

Elaine Luther
Metalsmith, Certified PMC Instructor
http://www.CreativeTextureTools.com
Hard to Find Tools for Metal Clay


#3

Thank you Elaine for your reply.

I have searched the PMCguild site and there is no one in India
teaching about PMC. Do you know of any online course? I’d love to get
started with it.

Thanks
Hema


#4
No. PMC, fired at 1650 for 2 hours, has the same density of cast
fine silver. 

Hmmm, not that I want to disagree, but this is not what I was told in
my certification class. We were told that it is NOT as dense, hence
the lighter weight. The burning off of organic material (we were
told) left spaces… fine cast silver doesn’t have these
spaces it is, much more solid.


#5
     Hmmm, not that I want to disagree, but this is not what I was
told in my certification class. We were told that it is NOT as
dense, hence the lighter weight. The burning off of organic
material (we were told) left spaces... fine cast silver doesn't
have these spaces it is, much more solid. 

Your explanation sounds logical… however, there is the question of
shrinkage after firing.???


#6

My understanding of the firing process is that the longer you fire,
the more dense the silver becomes, because the spaces shrink and the
silver grains become more densely packed - which is why shrinkage
continues with longer firing. After two hours the shrinkage has just
about gone as far as it can. This surely is the reason why longer
firing is used as a method of increasing strength?

Does anyone know the equivalent ‘full’ firing times for the other
types of metal clay, such as ACS, ACS 650, PMC+ and PMC3?

Pat


#7

Precious Metal Clay (PMC) is quite a fascinating material. It has
been around in the United States for about 10 years now. People
from all disciplines of arts and crafts are discovering it, we are
becoming familiar with its characteristics, we are beginning to push
the limits, experimentation is alive and doing very well, and there
is so much still to be learned about it. How much more fun can you
have than that? It’s not very often that something as revolutionary
as this comes along in the precious metals world.

Even though its name has the word ‘clay’ in it, don’t think of PMC in
the traditional, earthenware sense of the word. The term ‘clay’ only
designates the consistency of the material. Think of it as malleable
silver and malleable gold. It truly is silver and gold, which is
suspended in an organic binder that burns away when fired. During
the firing (sintering) process, as the binder burns away, the metal
particles bond and fuse together, leaving the final product as pure
(fine) silver and 24K gold.

There is concern in the jewelry industry, ‘how can it be
art?’,‘nothing worth keeping can be made from PMC’, ‘it’s nothing
but junk’, etc. I believe this is an unwarranted fear. PMC opens up
a whole new dimension in metalwork. It is an incredibly spontaneous
way to work, and allows a design to truly evolve, in the purist
sense of the word. True, when we first began working with PMC the
pieces came out looking and feeling rather ‘raw’. But as time goes
by the work is becoming more and more refined. Even though PMC is
incredibly versatile, I don’t see it as replacing metalwork, but
more as enhancing it. There is a lot that can be done with PMC, and
a lot of materials that it can be used in combination and
conjunction with, but every material does have its limitations,
including PMC. And, like any other material, there will be that
work which leaves a bit to be desired, but there will also be that
which is exquisite!

The following chart shows the strength of PMC. As you can see,
there are three formulations. PMC (the first generation), which
includes the 24K gold, is made up of particles that are rather flat,
oatmeal-like shapes. PMC+ (second generation, called PMC plus) is
made of round particles which, as they fire, become more tightly
packed together than the flatter shaped particles do, therefore
creating more strength and density than in PMC. PMC3 (third
generation) is also made of round particles, but the particles are
slightly smaller than those used in PMC+, which creates more
strength and density than PMC or PMC+. The longer PMC is fired, in
particular PMC+ and PMC3, the stronger it becomes, until it is very
close to the strength of sterling silver, which is 10.5 grams/cm3.

PMC
Silver content - 77% by weight
Density (unfired) - 3.5 grams/cm3
Shrinkage in size - 25-30%

Density (after firing at 900C)

fired for 5 minutes - NA
fired for 15 minutes - NA
fired for 2 hours - 7.9 grams/cms

PMC+
Silver content - 90% by weight
Density (unfired) - 6.0 grams/cm3
Shrinkage in size - 10-15%

Density (after firing at 900C)

fired for 5 minutes - NA
fired for 15 minutes - 9.1 grams/cms
fired for 2 hours - 9.8 grams/cms

PMC3

Silver content - 90% by weight
Density (unfired) - 5.5 grams/cm3
Shrinkage in size - 10-15%

Density (after firing at 900C)

fired for 5 minutes - 9.3 grams/cms
fired for 15 minutes - 9.5 grams/cms
fired for 2 hours - 9.9 grams/cms

Density (after firing at 700C)

fired for 5 minutes - 8.2 grams/cms
fired for 15 minutes - 9.1 grams/cms
fired for 2 hours - 9.5 grams/cms

PMC also has several firing times and temperatures. These allow for
quite a bit of versatility in the ways that PMC can be used, and in
the methods of application. For instance, in a PMC piece fired at
1650F only cubic zirconia or lab grown corundum can be used.
However, in PMC3 fired at 1110F stones such as peridot, moonstone,
certain garnets, and even tanzanite and diamonds can be fired in
place. Dichroic glass can be successfully fired in a PMC3 piece at
1200F-1225F.

Standard Gold PMC
Fahrenheit - 1830
Centigrade - 1000
Time - 2 Hours

Standard Silver PMC
Fahrenheit - 1650
Centigrade - 900
Time - 2 Hours

Silver PMC +
Fahrenheit - 1650
Centigrade - 900
Time - 10 Minutes

Fahrenheit - 1560
Centigrade - 850
Time - 20 Minutes

Fahrenheit - 1470
Centigrade - 800
Time - 30 Minutes

Silver PMC 3
Fahrenheit - 1290
Centigrade - 700
Time - 10 Minutes

Fahrenheit - 1200
Centigrade - 650
Time - 20 Minutes

Fahrenheit - 1110
Centigrade - 600
Time - 30 Minutes

And, besides the firing process, PMC+ and PMC3 can be torch fired.

PMC can be soldered, which allows for attaching to other metals.
PMC silver and gold can be combined with each other in various ways
into the same piece for stunning, two-color effects. Silver PMC,
being fine silver, is perfect for enameling. So, in our quest for
creative outlets, PMC has a wonderfully unique potential that is
just waiting to be discovered by our own individuality. The
question is?are we ready to get started?

Jeanette Landenwitch
http://www.jmlcreations.com


#8

I am working on verifying my statement that PMC +, fired at 1650 for
2 hours is an dense as cast fine silver. When I do, or don’t, I
will post.

My source: a presentation at the 2002 PMC Conference, by an engineer
from Japan from the Mitsubishi factory.

Elaine

Elaine Luther
Metalsmith, Certified PMC Instructor
http://www.CreativeTextureTools.com
Hard to Find Tools for Metal Clay


#9

No, I don’t know of an on-line course, but I heartily recommend the
video, “Push Play for PMC,” by Tim McCreight and Celie Fago.
Available from Rio Grande and elsewhere.

Elaine
Elaine Luther
Metalsmith, Certified PMC Instructor
http://www.CreativeTextureTools.com
Hard to Find Tools for Metal Clay


#10

Hello Hema,

I’m encouraging you to do a little reading about PMC. The website
http://www.pmclay.com, has a great summary of techniques and
answers to common questions in “Getting Started”. There are even
some video clips of basic techniques. Don’t miss a page in the
website. Many of your questions will be answered, including who the
international suppliers are.

Tim McCreight’s book “Working with PMC” is a great resource as well

  • easy to read and instructions for some nice projects. You don’t
    really NEED a formal class to get started. After all until it’s
    fired, with the metal clay you can simply roll it up and start over
    if you are unhappy with something. If you don’t have a kiln, use
    the PMC3 that can be torch fired. This is really cool - if you want
    to add to a fired piece, you can do so and re-fire to affix the
    additional bit. It IS more expensive than working with fine silver
    sheet or wire - but there are many possibilities.

Can you do it?? Yes you can!!
Judy in Kansas


#11

Is PMC economically reasonable? I’ve never used it - but mainly
because when I look at the small amount included in a package - I can
see how much further the same amount in silver sheet will get me.
Isn’t PMC mainly focused towards those that don’t have - and don’t
want - any silversmithing experience? I figured out how much it
would cost me to make a clasp in PMC versus using sterling silver and
I think the PMC would have cost me about $30, where the sterling cost
me about $3. I also have a friend who was making rings out of PMC
but has now said she won’t make any more because they are too soft
and bend and lose their form and shape after wearing them.

I don’t have anything against PMC - but I can’t see using it
because of the cost. I see it more as a way for those without
metalsmithing experience and torches to be able to make things that
would be hand-fabricated using sterling silver. Without sounding
negative, I put it in the same class as polymer clay… don’t flame me
please… I have seen some wonderful PMC pieces, but it’s not the
same as hand-fabricating out of raw metals.

One problem I have with PMC is that I have seen some of it sold as
"sterling silver" and I think that is incorrect.

Catherine


#12
Your explanation sounds logical... however, there is the question
of shrinkage after firing.??? 

No Shrinking AFTER firing, the shrinking occures during the
sintering process (firing). All of the products shrink, some will
shrink less than others. If you don’t fire longer, and hotter there
is less shrinkage, if you fire at the recommended time 2 hours, and
1650 degrees F, there will be more shrinkage and the product will be
MORE DENSE than the same product in diffferent forms . . .but even
at 2 hours for the max temp the end result will NOT be as dense as
Cast Fine Silver.


#13

Dear Hema,

In your position (in a country with no PMC teachers), I would start
by playing with clay–the ceramic kind–because it’s cheap and easily
accessible. Yes, you can jump right into PMC, and, yes, the texture
is somewhat different, but I would still recommend this.

If you have any friends that work in ceramics (especially
porcelain), get them to show you how to work with thin slabs, sprig
molds, slip trailing, texturing, miniature hand-building, etc. This
puts you on the learning curve for PMC and gives you some idea about
whether you will actually enjoy the process, before you spend a lot
of money. it’s also a lot of fun to play with clay. (You might find
yourself seduced, though, and forget all about PMC, so watch out.) An
additional advantage of starting with ceramics is that fired
clay–again, especially porcelain–can be turned into great stamping
tools, molds, etc.

If you like the process, invest in 3-4 books (I still think Tim
McCreight’s is the best), some videos (I assume they’re actually DVDs
now, and I don’t know about compatibility with the system used in
India), a tool kit, and some PMC (all available from our friends at
Rio Grande). It really is something you can teach yourself. Start by
doing what beginning potters do–make a bunch of pieces and, instead
of firing them, cut them up, examine them, and then re-hydrate them.

The major problem with learning on your own is not having access to
a kiln, which is a big investment (most ceramics kilns don’t have the
control necessary to fire PMC successfully). If you use the newer,
more expensive versions of PMC (which I don’t like as much–I love
the high shrinkage and texture of the original version), you can fire
without a kiln–lots of info is available on the Guild site, as well
as the Conference site. And, when it’s time to solder posts, set
stones, and finish your fired work, you’re back to regular jewelry
techniques. So…you really don’t need a PMC teacher. You can,
instead, become the first PMC teacher in India yourself!

Good luck!

Lisa Orlando
Aphrodite’s Ornaments
Elk, CA


#14
    Your explanation sounds logical... however, there is the
question of shrinkage after firing.??? 

PMC + only shrinks 12%. This is not a big deal.

Elaine
Elaine Luther
Metalsmith, Certified PMC Instructor
http://www.CreativeTextureTools.com
Hard to Find Tools for Metal Clay


#15
 I have seen some wonderful PMC pieces, but it's not the same as
hand-fabricating out of raw metals. 

“raw metals”? Your statements reveal your bias. It sounds like you
want someone to convince you.

If you don’t like it don’t use it. I don’t use it and sort of wrote
it off. But as time passes and I see what uses it has been put to I
find it more and more interesting.

Kevin Kelly


#16

Catherine,

I think the question is really, what do you want to do with it? I
think we’re only just beginning to see the answer to the question,
What is PMC good for? You are right – it’s more expensive than sheet
and wire, and if what you want to make is easily and economically
made with sheet and wire, then the only reason to make it from PMC is
a lack of metalsmithing skills.

However, I know people with very good metalsmithing skills that love
PMC because it does things sheet and wire don’t. You can shape PMC
in ways that would be incredibly difficult or even impossible using
traditional metalsmithing skills. It allows artists to work with
textures in ways completely different from sheet and wire, for
example. The ease with which you can incorporate organic forms, too,
offers many artists new inspiration.

Yes, it does permit people without metalsmithing skills to work with
metal – a real boon to artists whose enamel and glass work is far
ahead of their metal skills, for example. But it also offers those
with metal working skills the opportunity to do things that sheet and
wire can’t do, at least not easily.

If you are content with what you can make with the tools you have,
then there’s no reason to adopt PMC. If you’re curious, give it a
try, and see if there’s a place for its unique qualities among your
skill set. But saying PMC is inferior to sheet and wire is like
saying a hammer is inferior to a screwdriver. If you want to pound in
a nail, a screwdriver is a lousy tool. If you want to put something
together with screws, though, a screwdriver is a wonderful thing. And
sometimes a screw is a better choice than a nail.

Suzanne

Suzanne Wade
Writer/Editor
Phone: (508) 339-7366
Fax: (928) 563-8255
@Suzanne_Wade1
http://www.rswade.net


#17
One problem I have with PMC is that I have seen some of it sold as
"sterling silver" and I think that is incorrect. 

Right, it is not sterling, it is fine silver, which is silghtly more
valuable than sterling, and softer.

I am an experienced metalsmith who tried PMC and did not like it
very much. Since I have casting capabilities, there is a lot I can do
with various waxes that I think works better. The material is what I
would call “short”, that is, it breaks and crumbles like shortbread.
Stones set in it look sloppy to me, compared to hand setting in
bezels or with engraved beads. I think it is at its best when used
with a lot of freedom in terms of not trying to look too neat and
tidy. Each material is best when used as itself, not in imitation of
something else. So, of you want to do PMC, then have fun using that
rough crumbly edge, and the free, malleable look of it all! It is
what it is.

I see PMC as an interesting bridge for potters and other
craftspeople to get into using precious metals. Some of them may even
choose to develop traditional metalsmithing skills. If they don’t,
they will come up against problems when they decide to assemble
things with anything fancier than just a hole through the piece.

Please don’t get me wrong; I respect all materials. I just didn’t
like working in the stuff very much, myself.


#18

PMC is great for making three dimensional forms and hollow forms.
It also Allows setting stones ad firing with the stones in place.


#19
    However, I know people with very good metalsmithing skills
that love PMC because it *does things sheet and wire don't.* You
can shape PMC in ways that would be incredibly difficult or even
impossible using traditional metalsmithing skills. It allows
artists to work with textures in ways completely different from
sheet and wire, for example. The ease with which you can
incorporate organic forms, too, offers many artists new
inspiration. 

To my knowledge there is nothing that can be done in PMC that cannot
easily be done with either metalsmithing or casting techniques.
While I have started to see some more interesting work in PMC I
still am underwhelmed for the most part. And from a
mechanical/metallurgical point of view it is a inferior material in
its finished form.

Jim Binnion

James Binnion Metal Arts
Phone (360) 756-6550
Toll Free (877) 408 7287
Fax (360) 756-2160


@James_Binnion
Member of the Better Business Bureau


#20
PMC + only shrinks 12%.  

Even when fired at the highest temperature for 2 hours?