Open Firing Ceramics Definition

The pre firing of a ceramic material to remove all moisture and burn off any oxides and gases.

Open firing ceramics definition.

The final aim is to heat the object to the point that the clay and glazes are mature that is that they have reached their optimal level of melting. 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. It may or may not be glazed. In essence it s already been fired once and you re just going to put the glaze on it in order to fire it again.

Forming pottery by pouring slip into a porous mould usually made from potters plaster. If you can have the students take a look at the loaded kiln before the firing and then again when you open the lid. It is bisque fired and then glaze fired. A very fluid slip of high specific gravity obtained by deflocculation and used for forming ware using the casting process.

Most breakage in open outdoor pottery firings occurs because of either moisture in the clay or thermal shock. Whether vitrified or not it is nonporous does not soak up liquids. Ceramic work is typically fired twice. The firing process is measured in cones a standard unit of measurement that accounts for time and temperature.

The glaze firing is the most exciting part of the process for a lot of people. Click on the image to the left to see the vitrification process. Firing converts ceramic work from weak clay into a strong durable crystalline glasslike form. The melting that occurs is on the molecular level.

When the ceramic is fired a process known as vitrification takes place whereby the glass phase liquefies and fills the open spaces between the particles. Failure to do so could cause the piece to burst putting you back at square one. While it is true that pottery fired outdoors breaks more often than pottery fired in a kiln the breakage rate can be drastically reduced by taking certain precautions. Stoneware is a rather broad term for pottery or other ceramics fired at a relatively high temperature.

Firing is the process of bringing clay and glazes up to a high temperature. The purpose of this initial firing is to turn your pottery into ceramic material. A modern technical definition is a vitreous or semi vitreous ceramic made primarily from stoneware clay or non refractory fire clay. To the human eye pots and other clay objects do not look melted.

This is where the magic happens. Both of these issues are easily dealt with. When the body cools the glass solidifies and acts to bond the unmelted particles together.