Experiments with silverclay - part 2

Now that my pieces are thoroughly dry, it's time to fire them.

I placed my metal clay piece in the middle of the firing brick. You need a clock nearby for timing the firing and also a glass of water and metal tongs within easy reach. For safety reasons I also recommend wearing goggles. Make sure the place where you fire is well-ventilated - I set up a little station right by the open door to my veranda.

Ignite the torch and hold it at a 45° angle, about 4-5cm from the piece. Keep moving the flame over the piece. You will see a small amount of smoke and flame after a little while (this is the clay binder burning away), and then the piece will turn white. Keep the torch moving over the piece at all times. After a while you see the piece glow. When the piece turns a peachy-salmon color, begin to time the sintering cycle. Holding a sintering temperature (the peachy color) is important as it is sintering which joins the particles of silver together to create a strong and solid mass. Without this your piece will be brittle.

Sintering time ranges from about 2 to 5 minutes, depending on the weight and size of the piece. My pieces are quite small - about 1 cm across and 2 mm thick - so I held this temperature for about 2 and a half minutes. Increase or decrease the distance of the torch from the metal clay piece, depending on whether the color intensifies or fades. If the piece begins to look shiny or if you see sparks, the piece is near the melting point and you DON'T want this to happen. In this case just move the torch further away from the piece.

Immediately after firing, I used my metal tongs (tweezers will also do) to transfer the piece into the glass of water right next to the brick. This is called quenching. You can also move your piece (using a tool of course NOT your hands) to the cooler edge of the firing brick, and allow it to cool completely.

But whatever you do, DO NOT touch the piece until it is fully cooled!

At this point the piece will be white and still look like clay. Brushing and polishing, in the next tutorial, will bring up the lovely silver shine.