Fill the recesses with silver metal clay. Dry the pendant completely, and sand to remove any excess silver . Check your piece closely for blemishes before firing it.
Fire the pendant. Place the pendant on a 1-in. (25.5 mm) layer of activated charcoal (I use acid-washed coconut carbon) in a stainless steel lidded container in a brick kiln. Fire to 900°F (482°C) for 20 minutes.
Let the kiln begin to cool. When the kiln is 300°F (149°C) or cool enough to open, add another inch of charcoal to cover the now-blackened piece. Replace the lid, and fire at a 1500°F (816°C) ramp to 1400°F (760°C) and hold for two hours.
NOTE: If you’re using a muffle fiber kiln, you may have to raise the temperature to get the copper to sinter. However, too high a temperature will cause the copper and silver to alloy. I find this happens around 1500°F (816°C). All kilns are different, so test your kiln before firing your piece.
Remove the piece from the charcoal. Since this is a low temperature for sinter-ing copper, a second firing is occasionally necessary (see “Sintering Test,”).
If there are any cracks or holes along the silver/copper border, fill them with either clay, let the clay dry, and refire.
NOTE: Some cracks are so tiny that filling them is almost impossible; you may have to let a few go.
Finish the pendant. Polish the piece or tumble finish if desired.
NOTE: To add a little more pop, add a patina. I use Baldwin’s to accentuate the contrast between metals. A mirror finish doesn’t take patina well, so use a matting disc in a flex shaft or rotary tool to give the surface a slight matte finish before patinating.