Precious Metal Clay Tips and Product Information

by Jamie Smedley, Marketing Content Development, Fire Mountain Gems and Beads®

Metal Clay Information

Amazing precious metal clay, sold in sealed airtight packages, is made from salvaged precious metals found in household waste such as computers and electronics. This recovered precious metal is ground to a fine powder and then mixed with a natural binder and water to make a pliable clay that, when fired, turns into solid 22Kt gold or 99.9% fine silver! This process by which the binder is burned away and the particles of metal bond together is known as sintering. How ingenious is that! As the binder burns away during the sintering process, the precious metal clay mass will shrink by approximately 8 to 12%, depending on brand type and thickness of the piece. This trait can be used to your advantage with benefits to your design such as sharper texture details and tightening stone settings.

Skill-intensive metalsmith techniques aren't required to make beautiful objects d'art with precious metal clay. Basic pottery skills and techniques, with a few minor adaptations, are all one needs to use this innovative jewelry-grade medium. However, once the metal clay is fired and sinters to 99.9% fine silver metal, it can be worked using traditional metalsmithing skills and tools if you choose.

Art Clay® and PMC™ are two brands of precious metal clay. Original formula precious metal clays are very low in moisture, so they become dry to the touch--within 30 minutes depending on the climate where you live. A slow dry formula exclusive to Art Clay dries more slowly, giving you more working time with the clay--as much as an hour depending on the climate where you live. The following tips apply equally to Art Clay and PMC.
Precious Metal Clay Tips and Product Information
When you take clay out to use, only take what you will use immediately. To keep the unused portion moist and workable, keep it stored tightly wrapped in plastic cling wrap inside a small airtight container such as a sealable sandwich bag or old pill bottle with a piece of damp paper towel or sponge. If the clay you remove to work with dries completely before you are finished manipulating your design, refresh it to a workable state by lightly spritzing it with distilled water from a spray bottle or gently brushing water onto it until you can see that the surface is evenly moist. Avoid immersing or soaking in water because the clay can lose relief detail or dissolve entirely into a form of slip--a.k.a. clay mud. Purposefully creating and using slip as a tool is needed for gluing unfired clay pieces together.

After re-moistening dried out clay designs with water, seal them in an airtight plastic container and let sit to become thoroughly hydrated and pliable again. This is made easiest if you place the design to be remoistened in the container before you re-moisten it. Special care must be taken to evenly moisten the entire piece or cracking can result due to uneven drying. If you add a little too much water, it will be okay, just loosen the plastic container lid and give the clay a little bit of drying time to firm up enough to handle.

Suggested Tools to Use with Precious Metal Clay Projects

Workspace
  • Sturdy work surface such as an 8x8-inch piece of cut tile or 1/4 inch drywall
  • Smooth non-porous rolling surface, such as acrylic sheets, safety glass or a plastic report cover
  • Plastic wrap
  • Teflon® non-stick sheets
  • Wet sponge
  • Distilled water
  • Hot plate for speed drying
  • Olive oil or mineral oil
Flattening and Cutting Tools Shaping and Texturing Tools
Finishing Tools for Prefired Clay
Firing Tools
Finishing Tools for Fired Clay

Easily Create Custom Silver Jewelry

Metal clay is made of pure silver powder mixed with a non-toxic organic binder and water. In its raw state, metal clay can be shaped, molded or sculpted with simple tools and your hands. File and carve the clay once dry then sand for a nearly perfect finish before firing. During the firing process, the harmless binder burns away and the silver particles sinter (fuse) to form a solid 99.9% pure silver piece. Metal clay can be safely fired using a butane torch, gas stove or kiln. After firing, metal clay can be burnished to a gleaming finish.

Flattening
Place a ball of clay onto your non-stick worksheet. Using a brayer, roll it out to desired thickness. Slats can be used to create an even thickness.

Texturing
Move clay onto the texture of your choice, then place thinner slats on either side of the clay. Roll across the surface of the clay to achieve desired impression.

Cutting Out
Move clay to non-stick worksheet and cut out desired shape.

Sanding
Refine the surface of the clay using progressive grits of sandpaper and polishing papers.

Sticking, Rolling and Cutting

The fine particles of clay and binder, when wet, have amazing adhering properties, which is very helpful when sticking pieces together in a design. It is helpful to work on Teflon sheets because it will make picking up and positioning moist clay designs easier while preventing the bottom of the clay from drying out too quickly. Sparingly apply olive oil or mineral oil to hands, tools and work surfaces to keep wet clay from sticking excessively.


Reconstituted clay can be sticky and tends to adhere to your fingers and tools as you knead and work it. Precious metal clay is an upscale material that is too precious to waste. Recovering any clay lost from filing and sticking to fingers and tools can be done by using a paintbrush and a small amount of distilled water. Saturate the paintbrush with distilled water and use it to ''mop and sop up'' clay residue off of fingers and tools. Periodically rinsing the clay off the brush into the cup of distilled water will deposit the clay residue into the water and as the water evaporates it will leave behind a smooth clay slip.

Rolling clay out to specific thicknesses is easy with acrylic spacer strips or playing cards stacked and taped together. It is easy to begin with thicker strips and work your way down to thinner strips. Roll clay while it is wet.

There are several tools to cut moist precious metal clay such as the Klay Kutter™, Super Slicer blades, craft knives, razor blades and even the edges of a single playing card. Paper type precious metal clay can be punched and stamped with scrapbooking paper punches and embossers as well as cut with rectangle and deckled-edge scissors. Long razor blades or a single playing card can be used to slide between working surfaces and clay designs to aid in unsticking and removing the design from the working surface.

Dry and Refine

Precious metal clay must be completely dry before you can fire it. It is often easier to refine and finish a design that is completely dry. Finishing dry designs before firing also makes polishing and finishing after firing easier.

Clay has several stages of drying--semi-moist, leather hard and bone dry. Semi-moist clay is still wet and malleable but quickly begins to dry along the edges. Leather hard clay is still too moist to fire, and you can make an indentation in it with your fingernail or dental tool. Bone dry clay is completely dry and can be sanded and fired. Semi-moist and leather hard clays are the easiest stages of dryness to make repairs or add additional clay to your design.

Leather-hard clay can be fragile but it is still possible to lightly file, carve, sand, make holes in and otherwise continue to refine. It is much easier to finish leather-hard clay than trying to alter the clay once it is fired to sintered metal.
When sanding dried clay, use progressively finer grits to produce a smooth surface that is ready for polishing.

Constructing in a Dry State

Sometimes it can be easier to create clay designs and design components with dry clay. You can put them together with the use of clay slip. When creating designs in the ''dry state,'' you may encounter minor chips or dislodged clay pieces that can be repaired by remoistening the clay evenly with water and then applying precious metal clay slip to adhere pieces and fill chips. To do this, paint the slip along one edge of a remoistened piece and press the two broken pieces together. Let the join dry completely. Follow up with additional coats of thin slip over the seam until the join line disappears. Smooth out imperfections by thinning the surface of the applied slip with water. Once it is bone dry, you can sand the seam smooth and fire.

Clay slips and pastes are available premade or you can make your own by blending water with wet clay until it is the consistency of pudding. You can also collect unfired bone dry clay scraps over time and grinding them to powder in a non-porous pestle. Combine the powdered clay dust along with a few drops of water in a small jar and let it sit until all the moisture is absorbed. Add more powder or water as needed to achieve the right consistency. Blend the slip mix with a spatula or paintbrush. Seal the jar with a tight-fitting leak-proof lid. The slip needs to be thick enough to cling to the container bottom if held upside down, yet thin enough to spread easily with a spatula or paintbrush.

Firing and Polishing

There are several firing options once your precious metal clay designs are ready. You can fire them in a kiln, with a butane torch, on a gas stovetop or in a pot such as cast iron over intense heat. The manufacturer's directions included with each package of clay will tell you the correct temperatures and times for each firing application.

Once fired, metal clay appears to have a white or grey residue on the surface. This is actually not a residue, it is a bumpy texture caused by an effect known as scaling, for as the silver sinters, it sticks up from the surface of the metal as the binder is burned away. If you looked under a microscope at the metal, you would see that these scales resemble the texture of sandpaper. Rubbing the surface smooth causes the metal to become smooth and it will again reflect light and appear shiny. You can use a steel brush and soapy water to give the metal a brushed finish. To give the metal a brighter polish, use an agate or steel burnisher. Tumble pieces for 30 minutes with the appropriate steel shot and burnishing compound or polish using the appropriate wheels and polishing compounds with either a rotary tool or a bench lathe.

View the free metal clay online videos in the resource gallery for more tips, easy to follow directions and complete projects. Also check out the Secrets to Art Clay Success DVD hosted by Tamara Honaman, available for purchase for your home library.

Customer Comments

We would like to share some of the customer comments we received in response to the article, "Precious Metal Clay Tips and Product Information," featured in a newsletter. Please keep in mind that the comments expressed below are those of our customers and do not reflect the views of Fire Mountain Gems and Beads.

"Great advice and information, THANK YOU. Regards,"
- Beverley

"I found the information very helpful and appreciate the time and effort taken to compile and present it. Thanks"
- Ken

"Good stuff - a useful addition would be information on CZ's you stock that are fireable with the metal clay. Many thanks :O)"
- Jenne

"Very helpful and detailed for the beginner! I would love to read more tips on various tools and techniques in the future! Thank you!"
- Anonymous


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