Hobbies And Interests
Glaze Structure
Glaze can be made out of a number of different ingredients, but all glaze is essentially a form of liquid glass. Most glazes are predominately comprised of silica, a mineral that is synthetically processed and turned into a gel so that it can be applied to ceramics. Sodium and calcium are added to lower the melting rate, as well as aluminum, to increase viscosity.
Glaze Application
The glaze needs to be thoroughly applied on the ceramic with a paintbrush and the ceramic heated in a kiln at an extremely high temperature. As heat is increased, the molecules in the glaze move so fast that they start to break down, combining with other molecules to adhere to the ceramic. Do not apply the glaze on the bottom of the ceramic, where the piece will be resting on the kiln. It will cause the piece to stick to the kiln plate or shatter.
Cooling
Most small crafts and pottery projects must be heated in a kiln to more than 800 degrees Fahrenheit for close to an hour. The kiln must then be turned off so the ceramics can cool to the point where they can be touched again, which can take up to 15 hours. As the ceramic cools, the glaze begins to harden.
End Result
The end result is a piece of ceramic pottery that has a shiny coat of glass over it. The number of coats that you apply to will determine the thickness of the glaze as well as the overall shine. You can paint the ceramic with different colors or designs. There are a number of different glazes in the marketplace, each with their own recommended heating temperatures and times.