Ceramic Reduction Fire Definition

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.

Ceramic reduction fire definition. It is bisque fired and then glaze fired. Fuel burning kilns give the artist control of how much or how little oxygen enters the firing chamber and when. The piece is inserted into the garbage can and the lid put on. In reduction firing oxygen is prevented from interacting with the glazes during glaze maturation.

In traditional ceramics reduction firing requires a specially designed fuel fired kiln that restricts the flow of incoming air so there is enough to burn the fuel and no more in some cases it is restricted so that is actually less than enough to introduce carbon into the atmosphere. An oxidation atmosphere has plenty of oxygen for the fuel to burn. A reduction atmosphere occurs when the amount of available oxygen is reduced. The oxidation process for example can alter the color of the glazes or paint you ve chosen to use.

If you want more time in reduction without more heat work reduce the amount of fuel you may also need to reduce air intake and close the exit flue or damper even more so that the kiln is soaking rather than gaining heat. This may not sound like things that will affect your pottery but it can. Reduction causes most ceramic materials such as your glazes to melt faster. A reduction environment is an enclosed space with a reduced amount of oxygen.

Ceramic work is typically fired twice. Firing converts ceramic work from weak clay into a strong durable crystalline glasslike form. Usually this consists of a metal garbage can with combustible materials inside such as newspapers saw dust leaves or pine needles. Moving quickly the hot pieces are put into a reduction environment.

It is the lack of oxygen in the last part of the process that is critical for the desired effects. Most pottery professionals don t like to describe it especially to a persnickety chemist. Reduction firing is the exact opposite of oxidation firing.