Silver PMC - PMC Clay information and classes - About PMC
An Introduction to the Material, Tools and Techniques of Working with
Precious Metal Clay
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 occurring) 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.
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 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 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.
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.
Using simple tools and your own very talented fingers, PMC is rolled, pressed, squeezed, layered and molded, punched cut into a desired shape. Parts can be added, removed and refined as you go, making this a spontaneous and liberating process.
After it has dried, the PMC object is taken to a specific heat, this drives off whatever moisture remains, then burns away 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.
After firing, the object can be handled like any other silver of gold item. It can be soldered, burnished, buffed, tumbled, plated, etc. to achieve whatever finish you want.
Three Kinds of PMC
PMC Standard, the original PMC, is a much larger lump of clay than PMC+ or PMC3 as it has more binder additives. It is soft and buttery to work with. It fires to .999 fine silver and shrinks 29%. This shrinkage allows the artist to work larger than the final size, thus allowing ultra fine details.
This version, called "PMC +" is made of a differently shaped metal particle and contains less binder. The shrinkage rate is 12-15%. PMC+ offers three distinct firing options, two of them at lower temperatures than the original. Objects made of PMC+ can go from clay to metal in as little as 10 minutes.
PMC3, the third member of the family, is as dense as PMC+, fires as fast, but does all this at remarkably low temperatures. Three distinct firing options provide a range that makes this especially useful for co-firing glass, findings and some stones.
Available in Several Forms
This is the most commonly used form of PMC. A fast firing material, this clay fuses in as little as ten minutes in a kiln. Shrinkage is only 8-10%. You can shape it just like ceramic clay, using simple hand tools or even your fingers.
This form of PMC+ & PMC3 allows the user to extrude PMC+ & PMC3 in a string-like shape. Syringe form is slightly more liquid than clay form but not as moist as paste. Syringe form is useful either to decorate items made with other forms or to create objects such as filigree. The syringe come loaded with PMC+ & PMC3 and includes one tip that can be trimmed to allow different gauge extrusion. Other tips are also available.
This is a very versatile form of PMC+ & PMC 3. You can use it to coat actual organic objects like leaves to create an exact image of the original. This material is wonderful for making hollow forms, where paste can be built up on an organic form. In each instance, the organic form will burn off during firing, leaving the PMC object in the image of the original form.
This is the newest form of PMC+. It comes as a thin sheet of clay. This form contains no water, so it will remain pliable for extended periods (weeks) after the package it opened. You can fold the sheet like paper to form origami, cut it with decorative scissors or punch it using a creative craft punch.
Gradual cooling of hot glass to assure the glass wont cool too fast causing cracks or breaks.Aura 22:
Liquid stream of 22K gold that can be painted like nail polish onto fine or sterling silver designs.
A finding or part that attaches a pendant to a necklace.
Stone is held by a band of metal around the outside of the stone. The stone added after fireing.
Added to the powder mixture for the purpose of cementing it together to get a workable material.
Unglazed porcelain or ceramic.
Copper based alloys in which zinc is the principal added element.
Using a metal brush, brushing jewelry to get a non shiny effect.
Stone that has a rounded, domed surface with no facets.
Use dried cork clay shapes for making hollow PMC objects, it burns out completely when fired.
CZ is a lab produced gemstone that resembles a diamond, inexpensive and was developed in 1977.
Bottom point of a gemstone or facet that is ground at the base of a brilliant cut gemstone.
Crystallized glass when cooled to slow.
Glass that has been coated with a thin layer of metallic oxide.
A thin wire with a loop at one end, used between beads as a link.
One of the flat surfaces of a cut stone of glass.
Used to make jewelry, jump rings, clasps, hooks are all findings.
The widest perimeter of a gemstone.
Unfired bone dry clay objects.
kt measure of the fineness of gold. 24 kt gold is pure gold, 18 kt gold is about 75 percent gold.
Liver of sulfur:
Potassa sulphurata- mixture of various compounds of potassium and sulfur fused together.
Measures the hardness of a substance, Mohs scale ranges from 1-10.
Silver alloy that contains 92.5 percent silver and 7.5 percent copper and can tarnish with time.
Table of gemstone:
Large flat area at the top of a cut gemstone.
Temperature sensing probe of a pyrometer, used in a kiln to measure temperature.