Features of enamel raw materials
Pure metals or alloys of metals with a precise percentage composition must usually be used to prepare the enamel infrastructure. In the presence of impurities, bubbles appear on the surface of the infrastructure when heated. The minimum thickness of the metal in the preparation of the substrate is 0.8 mm because it increases the resistance of the substructure against all kinds of tensile and bending pressures, and as a result, it prevents cracking and glazing and deformation due to heat. Also, the desired surface should be smooth and uniform. The most widely used metals and alloys in the manufacture of enamel are copper, gold, silver, brass and bronze.
Copper: In the preparation of enamel, copper with a high purity percentage should be used, and the use of copper sheets or ingots resulting from the melting of used parts is not allowed. The appropriate thickness for the preparation of the infrastructure is at least 0.8 mm.
Gold: The thickness of the infrastructure and the grade of gold used in the preparation of enamel objects are determined by the manufacturer.
Silver: The silver used must have a minimum grade of 84, with a minimum thickness of 0.8 mm, which may vary depending on the manufacturer’s opinion.
Rice: Consumed rice, like copper, should not be obtained from the smelting of used parts, and a combination of high quality copper and zinc should be used with a precise percentage composition. The presence of impurities in the rice consumed during heating causes blisters on the surface of the infrastructure and reduces the value of the work, the minimum suitable thickness for the infrastructure is 0.8 mm.
Bronze in Iran This alloy is rarely used and must meet the conditions specified for rice.
If the infrastructure is made of glass or ceramic, it must have the desired quality for enameling.
Glaze
It is necessary to create enamel patterns on the metal to create a suitable surface that is created by the glaze. The glaze used is usually white glaze.
However, depending on the design, colored glazes may also be used. Enamel glaze becomes hard and glassy due to heat (up to 700. C). The possible composition of enamel glaze is a mixture of flint, silica, lead and tin. If tin is added to these oxide materials, the glaze will be cloudy.
Color
The dyes used in enamel are mostly obtained by combining metal oxides with certain types of salts. In the past, plant and mineral dyes were used, but today most of the dyes are ready-made. What is important about the colors chosen is that the intensity of the color depends directly on the temperature and the length of the heating time.
