Open Firing Ceramics Definition

Most breakage in open outdoor pottery firings occurs because of either moisture in the clay or thermal shock.

Open firing ceramics definition.

Both of these issues are easily dealt with. Click on the image to the left to see the vitrification process. The purpose of this initial firing is to turn your pottery into ceramic material. 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.

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. Failure to do so could cause the piece to burst putting you back at square one. When the body cools the glass solidifies and acts to bond the unmelted particles together. When it comes to bisqueing in essence the noun refers to any sort of pottery that you ve fired once and that has nothing chemically bonded in terms of water left within the clay.

The firing process is measured in cones a standard unit of measurement that accounts for time and temperature. Firing converts ceramic work from weak clay into a strong durable crystalline glasslike form. A modern technical definition is a vitreous or semi vitreous ceramic made primarily from stoneware clay or non refractory fire clay. A very fluid slip of high specific gravity obtained by deflocculation and used for forming ware using the casting process.

To the human eye pots and other clay objects do not look melted. Forming pottery by pouring slip into a porous mould usually made from potters plaster. The glaze firing is the most exciting part of the process for a lot of people. Firing is the process of bringing clay and glazes up to a high temperature.

Whether vitrified or not it is nonporous does not soak up liquids. Ceramic work is typically fired twice. 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.

Stoneware is a rather broad term for pottery or other ceramics fired at a relatively high temperature. The pre firing of a ceramic material to remove all moisture and burn off any oxides and gases. It is bisque fired and then glaze fired. This is where the magic happens.

It s important that the temperature rises slowly and cools slowly. When loading the kiln it is important to handle the pieces carefully so the glaze does not come loose. 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.