Kiln // Clay in the KilnWhat is a kiln? / Cones & Firing Temperatures Kiln Preparation & Care / How to fire a kiln

This is a labeled diagram of a top-loading kiln from the Skutt Kiln Master Operating Manual.

Kiln Vocabulary

Kiln Brick– Are made of refractory materials that are used to build kilns because of their resistance to heat.

Kiln Elements– The electric kiln elements are a series of spiral wires. They are set in to the kiln brick with a support ledge. The elements function as the heating system in the kiln. Over time, the elements will break down creating uneven heating in the kiln.

Kiln Furniture– Kiln furniture is used to pack the kiln. It includes the shelves, posts and other accessories. Shelves come in full and half sizes. The posts are used to hold up the kiln shelves and come in a variety of sizes from ½ – 12 inches. Stilts are used to hold up individual pieces of work above the kiln shelf.

Kiln Sitter– The kiln sitter is a small box located on the outside of the kiln with a trip lever and a timer. It was designed as a back-up safety device to prevent the kiln from over firing. How do you use the kiln sitter? On the outside of the kiln you should flip the lever up and push the claw down. On the inside of the kiln place the small(junior) cone with the number of your intended firing range in-between the metal bars of the sitter. Last you should turn up the timer and press the button in the middle of the trip lever. If the cone in the sitter melts and bends before the kilns program has completed it will trigger the kiln to shut off. Not all kilns have a sitter so do not be alarmed if you do not see one on your kiln.

For a bisque firing = cone 06 in the sitter. For a low-fire glaze = cone 03 in the sitter.

Kiln Wash– Is a combination of 50/50 Kaolin/Alumina mixed with water. Kiln wash is used to create a barrier between the kiln shelf and the ware placed on top. This layer of wash protects the shelf if glaze drips off a piece.

Pyrometer– A pyrometer measures the temperature inside the kiln with a thermocouple or probe. It will give you a mechanical temperature at that time and place in the kiln. It is important to know how fast or slow the temperature is climbing. The pyrometer cannot give you the effect of time and temperature so it is best to use in combination with pyrometric cones. They come installed in electric kilns but you can also purchase them separately if needed for firing an atmospheric kiln.