Lee Marshall said:
Seems to me, being somewhat of an outsider in that I make equipment
rather than jewelry, is that PMC with it’s unique properties should be
used to make something that cannot be made, or would be very difficult
to make with conventional techniques.
Right on, Lee!
The only benefit I can see to it is it’s aprox 50% shrink when heated.
That way any ‘oops’ in the carving/molding are reduced by 1/2.
Looks like its a product waiting for a slick promoter.
Dave
Dave & Lee,
Actually, the shrinkage factor makes the details inthe mold more apparant.
This was particularly nice when one had a good mold!
Elizabeth
Okay, here’s a question for those of you who have played with
PMC:
What kind of adherence can you expect from this stuff? Let me
explain what I mean: I don’t do any hot work right now; I twist
and weave and stuff like that. I’m wondering if I could form PMC
around poky wire ends and make a smooth finish, then fire and
have it shrink on tight.
I do not have a kiln, but I might try to borrow the use of one
if you guys think this might work. Also, I hate pickle and
refuse to work with it (silly twit is shooting herself in the
foot, I hear you say.) Do you PMC users think I can get away
with minimal mechanical treatment of the PMC after it is fired?
Color does not worry me (as long as it doesn’t look ugly, of
course…)
Your thoughts, anyone? or be so kind to take my questions to
Tucson when you go, and give me a report? Thanks!!! wish I
could be there too.
-ieva swanson
HELP! I have been working with Precious Metal Clay since January. I like
it and plan to continue with it.
I would love to hear more about your experiences with precious metal
clay. I have read much about it, and have used it once, unsuccessfully.
I’ll answer anything I can about PMC. I may not be the most skilled in it
on this forum, but I have been having a good time with it anyway!
What kind of problems did you have?
Candy
I am curious about the Precious Matal Clay. Has anyone used it
for anything? I’m wondering if it has a future and if so for
what? Seems like it might allow some artistic freedoms.
Bob B
I am curious about the Precious Matal Clay. Has anyone used it
for anything? I’m wondering if it has a future and if so for
what? Seems like it might allow some artistic freedoms.
Bob B
I have some but have not used it yet(no time), I could answer
any general questions you have about it. I been following it
since it was first introduced in this country, at Haystack a
couple of years ago. It shrinks 30-40%, is more porous, and is
only available in pure metals: fine silver, 24k gold. They make
it in alloys but since a oxygen free environment is needed for
firing it, which would require a special kiln, they have not
marketed it. I’ve had extended conversations with Tim McCrieght
and Fred Woell on the subject and Fred is teaching at UMass
Dartmouth this semester, so any questions I can’t answer, I’ll
pass on to Fred.
Ed Colbeth wanderer@sprynet.com
Student, Metalsmith
Fairhaven, Ma
Actually, I really am enjoying PMC. There are others on this
forum with quite a bit lower opinion of it!
I have been working with silver PMC since January. I received
my first bit of gold just before I left for this vacation I’m on.
Almost didn’t come…I’m dying to try it.
If Charles Brain is out there, he can tell you more about PMC.
He took a class from Tim McCreight, I believe. I took a class
from GIA in Tucson.
It’s not intimidating at all. I worked with it before doing the
class. If you have someone to teach you, you learn a lot of time
saving things by not having to reinvent the wheel.
Candy
Hi,
If they need an oxygen free environment to fire it they could
definitely use a product we use in dental lab work. A dental
porcelain furnace sucks a vacuum and then fires up (electric)
fot enough to melt fine gold, in fact that is what we use to
calibrate the pyrometer!
Skip
Skip Meister
NRA Endowment and
Instructor
@Skip_Meister
05/09/9702:18:14Hi, Bob:
Have just dropped a class in PMC for the following reasons:
The kiln temperature has to be EXACT - there’s very little room
for variance. As a potter, I found the clay dried (then cracked)
very quickly while working it. Water helps, but needs time to be
absorbed into the clay body. It also adheres easily to the skin,
even if using oil.
Shrinkage is not proportionate. It’s expensive.
I have yet to see any truly impressive pieces done in this
medium that couldn’t be approximated by casting or fabrication.
Best, Gayle Morris
If they need an oxygen free environment to fire it they could
definitely use a product we use in dental lab work. A dental
porcelain furnace sucks a vacuum and then fires up (electric)
fot enough to melt fine gold, in fact that is what we use to
calibrate the pyrometer!
I wonder if it as simple as that. Since all we can buy here is
pure silver or gold, I would like to explore the possiblities of
the different karat golds…especially if they come in colors,
like rose gold. (It seems I remember reading that they do.)
I wonder if the knowledge of dental ovens is known by the people
who introduced PMC to the US.
Candy
Not being a potter, I am not hindered by the drying problem. If
I sense the clay getting too dry, I just dab it with water before
the drying inhibits its pliability. It only takes a minute or
two for the water to be absorbed.
What I like best about working in PMC is it’s newness. I like
to find new ways to do things and to experiment. Since this is a
relatively new medium; I see the field of possiblities as
endless.
I have not yet learned how to cast, so I hold no strikes against
PMC in this area. I like making my own beads. Each pattern may
be similar, but each is unique.
As for kiln temperature…trust me, I know what a difference 50
degrees F can make…from potential jewelry to scraps being saved
for when I DO learn to cast! But actually, it takes patiences
and perseverance. I have a small ceramics kiln, bought a
pyrometer and am hoping I have modified things enough that I can
buy a controller. It’s a nuisance, but I have hopes of buying a
fusing oven that will eliminate a few of my trips out to the
garage to make sure I’m not on the way to a “melt down”. It
would be nice to have the kiln or oven in the same room with me!
In short…there are pros and con to everything. You either
like PMC or have no use for it. But I recommend not throwing
away the opportunity to find out which side of the table you are
on!
Candy
P.S. The shrinkage is a point I would like to find some kind of
scale or control over!
As i understand it the dental vacuum kilns are primarily
designed for a 15 minute firing cycle. Can they be used twith the
two hour PMC cycle?
Charles
Brain Press
Box 1624, Ste M, Calgary, Alberta, T2P 2L7, Canada
Tel: 403-263-3955 Fax: 403-283-9053 Email: @Charles_Lewton-Brain
Metals info download web site: Learning Center - Ganoksin Jewelry Making Community
Product descriptions: http://www.ganoksin.com/kosana/brain/brain.htm
Links list hosted at the Metal Web News:
http://tbr.state.tn.us/~wgray/jewelry/jewelry-link.html
I E-mailed Mitsubishi Materials, the makers of PMC for info
about alloys.
http://www.mmc.co.jp/english/business/dream-gold.html this is
there web sight, not much info, but an interesting picture of an
oragami(sp) crane make with thin sheets of PMC not available in
the US.
Ed Colbeth wanderer@sprynet.com
Student, Metalsmith
Fairhaven, Ma
Hi,
The new dental furnaces are all computer controlled, and yes,
they have a “firing cycle”, but the low end manual models are
totally under your control. You can control the rate of climb,
and the duration of the firing cycle. You can even bring the
temp down to the ‘idle’ temp. while still under vacuum. These
furnaces were the mainstay of the industry and there must be a
’zillion’ of them floating around in used condition out there
somewhere. Remember they require a vacuum pump to be attached,
but you can even rig the one from your vacuum investor or maybe
even purchase a used one from the supplier.
If you have any questions you can E-mail me, and I’ll be happy
to answer any questions that I can.
Skip Meister
NRA Endowment and
Instructor
@Skip_Meister
05/11/9709:32:22I’ve read some of you have tried the PMC material and don’t like
it. I am currently experimenting with using artist’s hard
plastecine to make models and then making a mold using investment
and then making a wax model from the plaster model. After six
tries I’m finally having some success and think that maybe what
people like about PMC as an easily formable material this
technique might appeal to. You’re limited to bas-relief type
models though, no rings or whatever though you could make a two
part mold. If anyone is interested I could post the instructions
and save you alot of grief if this interests anyone. I’m casting
my first piece from this tonite. DAve
www.opendoor.com/stephensdesign/crystalguy.html
Crystalguy Art Jewelry, Magical Art Jewelry for the Enlightened Mind
Dave
I would be interested in your osting the instructions for making
models. If you prefer you could e-mail them to me only, at
RBUCK83133@aol.com.
Thanks
Bob B
Hi Dana Carlson,
I just checked your work of PMC on the orchid gallery. They are
just beautiful!!!
Have you sold these pieces yet? If not, how are you going to
price your pieces?
I have a computrized kiln, and I just can’t wait to try my next
pieces.
Dave, I’m intereted in how you have used the plasticene to
construct a plaster mold. How did you get the plasticine out? I
would appreciate your directions, if you haven’t already sent
them out to the group. (I’m way behind in my mail) thanks.
Foxymom (Ruth)
Ruth:
actually you’re the only one who asked! The mold is the simple
part, if you’re making a wax from the mold thats where it gets
tricky. First of all you need to use ARTIST’S grade plastecine. A
number four or five grade. Any art supply store can order it for
you if they don’t stock it. This is pretty hard stuff and easier
to work with than that gooey kid’s stuff that comes in such gross
colors. The technique is described in a wax carving book thats
pretty good but the description isn’t very good. Bascially
you’re making a bas-relief piece with your plastecine, so you can
add layers on layers. The plastecine is easy to form and work
with is what I like. Work on a piece of glass and you can have a
sketch of your shape underneath the glass to use as a guide. When
you got your clay to perfection, mix up some investment, but mix
it thicker than you would for casting. Make a little cardboard
rim to go around the model and then seal the bottom off with
kid’s plastecine. Paint the investment on with a brush getting
into all the cracks etc. and vacuum your investment before doing
this. Then once its covered good pour the investment in and cover
the piece. Wait about two hours for it to set up good then unseal
the paper flask and twist it off the glass. The investment will
still be holding alot of moisture which repels the oil based
plastecine so its fairly easy to pick the plastecine out of the
mold. A toothpick or wax tool works good. You should get a pretty
good mold from this but you will have some bubbles and spots that
aren’t perfect.
To make a wax from the mold is a little tricky so you might not
want to put a lot of effort into your first try. Here’s what you
do thats worked for me so far after about six tries at this. Put
your mold in a kiln and dry it out at about 200-300 degrees for
a couple hours. It needs to be real dry for the next step. Get
some glycerin from your drugstore for mold release. Heat the mold
to 160 degrees farenheit. Once its heat-soaked at that
temperature take it out and slop alot of glycerin into the mold
covering all parts and sides of walls etc. Put it back into the
kiln and just AS SOON as the glycerin has just soaked into the
mold but not glistening wet pull it out and spoon in your wax. I
used a coffee scoop from Starbucks. small scoop. Now here’s the
tricky part. I used Ferris green wax which melts at 230 degrees.
At that temperature the wax will bubble the glycerin and ruin
the wax. I mixed in some candle wax to lower the melting
temperature of the wax to below boiling point for water, which is
also why you don’t want to heat the mold too hot either, 160
worked for me. I mixed almost half candle wax (canning wax
actually) with the Ferris Green, probably could have used a
little less. I think injection waxes might work real well too.
If the mold is damp or anything gets near water’s boiling point
you get bubbled wax and its ruined. Let the wax dry real well and
it should pop right out. If not, soak the investment and break it
slowly away. You will have some clean-up to do on the wax, this
is a crude technique overall but sure has potential for some cool
things to try. Of course you’ll need to bur out the back of the
wax when its out to get the weight down for casting. I imagine
some cool textural effects etc. could be done with this
technique. I’ll have a simple piece I did on my website in a week
or two using this stuff. Let me know if you have anymore
questions…Dave
www.opendoor.com/stephensdesign/crystalguy.html
Crystalguy Art Jewelry, Magical Art Jewelry for the Enlightened Mind