The Burning Question Answered
(more or less)
Precious Metal Clay (also called PMC or just Metal Clay) is a compound made up of re-claimed metal particles and an organic binder. When it first hit the market in the early 1990's it was only available in Fine Silver or 22k Gold, but now it is available in several different metals including Sterling Silver, Copper, Bronze, and Even Steel.
(in case you are wondering about the difference between Fine Silver and Sterling Silver; Sterling is often referred to as ".925" and that's because Sterling Silver contain at least 92.5% pure Silver. Fine Silver on the other hand has a higher silver content, .999 or 99.9%)
Working with metal clay is similar to working with any other type of clay. It can be shaped, rolled out into a sheet.
The great thing about Metal Clay is that it can also be worked with once it has dried. It can be sanded or drilled. You can even connect dried pieces of clay together with just a bit of water.
Before firing you can even embed Fine Silver wire (or whatever other type of Metal Clay you are using) into the clay to add bails or even different elements to the piece. Once the piece are fired, the embedded wire fuses with the metal particles in the clay.
Due to the high temperatures if the kilns (usually 1600 degrees Fahrenheit, again, depending on the type of clay) and the fact that the clay shrinks when it's fired, pieces are supported beforehand. In the photo below, the I-Beam Necklace is place in a ceramic dish filled with vermiculite to help support it. A pre-sized ring insert is used to make sure that the Ring shrinks down to the correct size.
While in the kiln the organic binder in the clay burns away and the metal particles fuse together in a process called Sintering. The longer the pieces fire in the kiln the longer the particles have time to fuse together, in other words, the longer the piece fire the stronger it becomes, which is why I always fire my pieces for a minimum of 2 hours.
After the pieces come out of the kiln they finished using classic metalsmith techniques, like sanding, polishing & adding patina. Most Metal Clay pieces can even be soldered after firing as well. One is only limited by their imagination...