According to different coating methods, cast iron enamel frit can be divided into wet cast iron enamel frit and dry powder cast iron enamel frit.

The wet cast iron enamel process is mostly used for lighter workpieces, such as pots and hobs. In order to avoid the deformation of the green body at high temperature, the firing temperature is relatively low, about 760~790℃, and the firing time depends on the weight of the casting, usually about 5~15 minutes. Wet cast iron enamel can be adjusted to any color, the color and appearance of the finished product is better than ordinary enamel, and the mechanical strength is also stronger.

Lead-containing enamel is not suitable for making food-contact workpieces. Wet cast iron enamel can be ground coated first, or directly on cover coat. However, this kind of ground coat does not require cobalt oxide or other oxidized pigments, and most of the cover coats with low reflection are used as the ground coat. The addition of zirconia to the ground coat can significantly increase its milky whiteness and reflectivity (called white ground coat).

The following table lists the composition and chemical components of various wet cast iron enamels, which can be divided into lead-free and low-lead enamels. It can be seen from the table that the composition of the lead-free enamel frit is very similar to that of the steel plate frit, and its fluidity can be increased by adding a small amount of barium carbonate and zinc oxide. Usually low-lead enamel often adds antimony compounds as opalescent agents in the frit. If its lead content is high, its color will turn to cream or yellow. The total amount of feldspar, borax, and quartz contained in low-lead enamel accounts for about half of all ingredients. The amount of sodium-soda ash is very small, and Chilean saltpeter is very helpful to the milky whiteness of antimony compounds. The lead oxide content ranges from 9 to 17%, with an average of 14%. Most low-lead enamels add a considerable amount of barium carbonate as a substitute for lead oxide, and zinc oxide, chalk, and boron oxide are used as fluxes.

Composition of wet cast iron enamel frit (%)

The abrasive used in wet cast iron enamel frit is similar to steel plate enamel. The plastic clay is about 5 to 7% of the frit, and the opalizing agent is added with 4 to 8% tin oxide or zirconium oxide, and electrolyte is added to adjust the properties of the enamel slurry.