The copper is carefully washed and then sprayed with a light adhesive. A fine (200 grain) enamel is then sifted on one side and fired at 1,500 degrees for two to three minutes. The two pieces are put into an acid bath to remove the copper oxide – and then cleaned again. The process is repeated. Once both sides are enameled, the piece is again sprayed with adhesive. Next, a piece of colored glass, called millifiori, is placed on the jewelry pieces and fired a 1,550 degrees for four minutes. Since the glass piece has an irregular bottom, it moves about on the metal. When the piece has cooled, it is tilted so that when fired again, the glass slides back and both pieces look the same…practically.
Making Etched Enamel Bowls and Plates
The process is somewhat different for each piece. One plate in my collection was made by painting a piece of copper with an acid resistant asphalt, which is like tar. It was then placed in a 15-20% nitric acid solution. To achieve a sharper design, I took the plate out of the acid, and applied more acid resist. Once satisfied with the design, I cleaned the metal with lacquer remover and brushed it carefully with Dawn detergent, using a fine brass brush.
Next, the cleaned copper was sprayed with a 10% adhesive solution, and the enamel was applied by carefully sifting the glass (which looks like granulated sugar) in a thin layer. It was then sprayed again and sifted again and sprayed one more time. The piece was then set under a heat lamp to dry, before being fired in an electric kiln at 1,500 degree F. The time of firing depends on the size of the piece.