[Nfb-krafters-korner] Difference between PMC Precious metal clay and polymer clay

[AUDREY WELLNER]

Hi Joyce
     Just getting a chance to answer your statement between PMC (Precious Metal Clay) and polymer clay.  See the reference to the origins of PMC below.  The basic difference is 
     PMC (Precious Metal Clay) contains real silver particles, whereas Polymer clay doesn't.  This makes the clay extremely expensive and fragile after baking.  After taking one of the very first classes to become certified to teach PMC work the product has grown in leaps and bounds in new features (hardness, color, etc) and hard to keep up with such an expensive hobby. You would have to have a love for silver jewelry for this one.
     Again, after baking the difference between the two is dramatic - your PMC crafted item when polished will look exactly like a piece of silver jewelry, unlike something done in polymer clay that finishes like a clay, pottery, or plastic resin like finish.  
     Think twice about starting in this media--beginner classes in CT start around $250 to $500 and the kiln (used) runs another $500. I haven't kept up on the price of the clay--but it's sold by the ounce, instead of the pound.  
  Just a little background history--- 
  Audrey Wellner
  Rencraft Designs
   
  An Introduction to the Material, Tools and Techniques of Working with Precious Metal Clay
   
  What is PMC?
  Precious Metal Clay represents a dramatic development in the handling of precious metals. PMC consists of microscopic particles of silver or gold suspended in an organic binder to create a pliable material with a consistency similar to modeling clay. PMC can be worked with the fingers and simple inexpensive tools to create a vast range of forms and surfaces that would be unattainable or laborious with traditional techniques.
  When heated to a high temperature, the binder burns away and the metal particles fuse to form solid metal that can be sanded, soldered, colored and polished like conventional material. This booklet describes some of the techniques devised for PMC and will guide you through your first firing experience.
  History
  Precious Metal Clay was developed by scientists working at the Mitsubishi Materials Special Products division in Sanda, Japan. After years of experimentation the first patents were awarded in the early 1990s with many additional materials joining the family of products. The principle ingredient of PMC is gold or silver, reduced to tiny flakes smaller than 20 microns in size. As a point of reference, it would take as many as 25 of these particles clumped together to equal a grain of salt.
  The other ingredients in PMC are water and an organic (naturally occuring) binder. After firing, the water and binder have completely burned away so what remains can be hallmarked as .999 silver or gold.Dried out or unwanted objects can be refined just like conventional precious metal.
  How Does It Work?
  Under the proper conditions, crystals of metal fuse together in the same way that droplets of water run together to make larger puddles on the window pane. In the case of metals, oxides (tarnish) that form naturally on most metals prevent this from happening. The solution here is to use precious or noble metals in their pure state. These do not readily oxidize so even at the high temperatures needed to induce fusion they remain free of coatings. This explains why there is not a brass or sterling version of PMC - short of firing in a vacuum it won't work.
  Form
  Using very simple tools and your own very talented fingers, PMC is rolled, pressed, squeezed, layered and molded into a desired shape. Parts can be added, removed and refined as you go, making this a spontaneous and liberating process.
  Fire
  After it has dried, the PMC object is taken to a specific heat (as described on page 9). This drives off whatever moisture remains, then burns the binder. This goes off as a harmless smoke. At this point the PMC is a fragile porous metallic husk. At higher temperatures the particles melt into one another to form a solid dense metal. Depending on the type of PMC, this can take from 10 minutes to two hours.
  Finish
  After firing, the object can be handled like any other gold or silver item. It can be soldered, burnished, buffed, tumbled, plated, etc. to achieve whatever finish you want.

Blindhands at aol.com wrote:
  Please tell me if you mean PMC-polymer clay?

I am not sure, but I am checking into having someone demonstrate polymer 
clay at the Dallas convention. This is still in the working stages. More to 
come on that.

Joyce 



**************Wondering what's for Dinner Tonight? Get new twists on family 
favorites at AOL Food. 
(http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001)
_______________________________________________
Nfb-krafters-korner mailing list
Nfb-krafters-korner at nfbnet.org
http://www.nfbnet.org/mailman/listinfo/nfb-krafters-korner
To unsubscribe, change your list options or get your account info for Nfb-krafters-korner:
http://www.nfbnet.org/mailman/options/nfb-krafters-korner/rencraft%40snet.net