Ceramic Clay Firing Temperatures And Times

First it is important to know that the maximum cone rating of a stoneware or porcelain clay is the temperature at which it vitrifies.

Ceramic clay firing temperatures and times.

It is bisque fired and then glaze fired. As well as firing clay the glaze must also be fired to maturity. The clay goes from this soft totally fragile substance to one which is rock hard impervious to water wind and time. Firing temperatures cone equivalents.

However anywhere from 2305 to 2336 1263 to 1326 may be appropriate depending on the specific clay used and desired effect. Firing at cone 06 to 04. Firing clay from mud to ceramic. As a kiln is firing up and cooling down the changes in temperature make some profound changes in the clay.

Generally bisque firing is done between cone 08 and cone 04 no matter what the maturation temperature of the clay and of the glazes that will be used later. Between the range of cone 8 and cone 12 high fire stoneware will mature. Raku clay is usually bisque fired to cone 04 to 1 clays that are to have crystalline glazes should be bisque fired slightly higher than normal i e. Ware must be fired at least once at a higher temperature first in order for the clay body to mature.

This is the hardening tightening and finally the partial glassification of the clay. The ware will often not only go through a bisque firing but also a higher temperature glaze firing. A cone 04 glaze firing schedule with down firing. Firing converts ceramic work from weak clay into a strong durable crystalline glasslike form.

All cones mature with time and temperature. By cone 08 the ware is sintered and has become a ceramic material. The temperature needed to transform soft clay into hard ceramic is extremely high and is usually provided by a kiln. The type of kiln used and the firing schedule will also have an effect on the color and texture of the glaze.

This range is usually used for luster glazes and very low firing overglazes. At the same time the clay body still is quite porous and absorbent enough for easy glazing. The goal of bisque firing is to convert greenware to a durable semi vitrified porous stage where it can be safely handled during the glazing and decorating process. You cannot fire pottery in a home oven because ovens do not get up to the high temperatures of more than 1 500 degrees fahrenheit that you need for firing clay.

It is important to match the firing temperature of the glaze to the maturing temperature for the particular clay body. Because the bisque firing has already changed the clay into the ceramic material glaze firings can increase temperatures faster at the beginning and middle of the firing. The average firing temperature for high fire stoneware is 2381 1305. People want to know if they can fire a certain clay to a certain cone.