The Ceramic Firing Process

Firing clay is necessary to create durable wares and the more you know about the ceramic firing process the more control and success you will have with your pots.

The ceramic firing process. The next step is to put the piece into the kiln for the first round of firing called a bisque firing. Again the firing process is a three day affair. The raw materials used to form tile consist of clay minerals mined from the earth s crust natural minerals such as feldspar that are used to lower the firing temperature and chemical additives required for the shaping process. Bisque firing is the typical and very important first step in the ceramic finishing process.

After the glaze firing temperature of 2350 degrees f. Has been reached the pots cool and on day three are unloaded and stored in the room in the wooden cabinet near my office. The materials experience irreversible structural changes reaching the proper ceramic structure that is responsible for the final properties of the product. Ceramic work is typically fired twice.

Ceramic glaze is an impervious layer or coating applied to bisqueware to color decorate or waterproof an item. Firing also known as sintering or densification the ceramics pass through a controlled heat process where the oxides are consolidated into a dense cohesive body made up of uniform grain. The firing process is the key step in the manufacturing of ceramic products because it controls their properties. For earthenware such as fired clay pottery to hold liquid it needs a glaze.

It is bisque fired and then glaze fired. That s why we decided to post this excerpt from linda bloomfield s book science for potters as a handy guide to just what happens inside the kiln when firing pottery. Firing converts ceramic work from weak clay into a strong durable crystalline glasslike form. Firing clay from mud to ceramic.

The purpose of this initial firing is to turn your pottery into ceramic material. 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. Once the ware is out of the kiln we recommend you promptly take it home or store it in your locker. The firing process is measured in cones a standard unit of measurement that accounts for time and temperature.

Done between 1657 f cone 010 and 1945 f cone 04. During a bisque firing both physical and chemical water is driven out of the clay and organic residue burns out. While firing may not be the most visually exciting part of the ceramic making process it is the most critical part as it ensures the creative energy put forth in all previous stages will be properly preserved in a durable functional end product. Potters apply a layer of glaze to the bisqueware leave it to dry then load it in the kiln for its final step glaze firing.