How to Make an Etched Copper Bowl
Materials and Tools:
14-inch round copper bowl blank
enameling adhesive (such as Klyr-Fire)
enamel powders: clear, black, transparent peacock green, transparent Nile green
spiked firing trivet
sharp carving tool for sgraffito design
wet-diamond polishing machine
container of water
1. Preheat the kiln to 1,500 degrees Fahrenheit.
2. Place a 14-inch copper bowl blank in the kiln for about a minute, until it glows orange, and then drop it into water to cool.
3. Curl up one edge of the bowl to about 90 degrees with your hand.
4. Hammer the form with a wooden mallet on an anvil stake to flare and smooth the curves.
5. Hammer the bowl's foot flat with a metal ring.
6. Clean the bowl by putting it into the kiln for about a minute, until it's ashy gray, to burn off grease and wax.
7. De-scale the bowl by placing it in a pickling solution for about 10 minutes to remove black fire scale. Rinse the bowl in cool water and dry.
8. Brush the enameling adhesive solution on top with a large makeup brush.
9. Water down the enameling adhesive in a spray bottle. Hand-sift three layers of clear enamel with a sieve, and mist the watered-down enamel adhesive between each layer.
10. Turn the bowl over and place it on a spiked firing trivet. Brush on enameling adhesive and hand-sieve black enamel onto the underside of the bowl.
11. Turn the bowl right side up and place it on the spiked trivet. Scratch a sgraffito eucalyptus design (or any design) into the unfired clear enamel on the inside of the bowl with a sharp carving tool. Brush away the loose enamel.
12. Let the design dry for about 10 minutes and then fire it for about two minutes in the kiln, until glossy and smooth.
13. Remove the bowl from the kiln and place it on a stone slab to cool.
14. Wearing a dust mask, repeat steps 8 and 9, using peacock green for the first layer and Nile green for the second and third layers.
15. Fire the enameled bowl in the kiln immediately for about a minute and a half, until glassy and smooth.
16. Place the bowl on a stone slab to cool for three to four minutes.
17. Smooth and clean up the edges with a wet-diamond polishing machine. Rinse it in water and dry.