What are "Kiln brick" and "Fiber"?

Even though potters weren’t designer and builder of the ceramic kiln themselves, there are two main materials that make up the kiln that potters should know and consider them when deciding to buy a kiln, the two main materials are 'kiln brick' and 'fiber'


'kiln brick' is a refractory insulating brick with fire resistance up to 1770 degrees Celsius. It is made from a mixture of kaolin, alumina and refractory clay mixed with air or other organic matter in the form of thick slip which causes the composition of the cavity resembles a natural sponge. When fired, the air voids in the brick produces less porosity insulating properties than heavy bricks hence weighs less. As a result, the construction of the ceramic kiln is lighter and can be easily trimmed with a hand saw and chamfered to a suitable shape to fit in various corners of the kiln so it is easy to drill holes to see the lights and can be used to build the inner wall of almost any kiln. Although the price is higher than ordinary heavy bricks, it saves a lot of fuel in firing. Because it helps to accelerate the firing temperature faster and also cools quickly after use.

fiber’ or ceramic fiber is a fiber made from a high-temperature ceramic material. It has a fire resistance value from 1,200-1,400 Celsius. It is lightweight and withstands rapid heat. But at the same time, it cools quickly, which is a disadvantage for slow-cooling kilns. Most are made of pure aluminum silicate which is melted at high temperatures and through high pressure steam to the liquid mixture of alumina silica and kaolin to separate these components into fibers of different sizes.

Although this fiber is expensive, it saves fuel than other types of insulation. It heats the ceramic kiln to the desired point with less heat loss. At the same time, fiber-based powders are harmful to the skin and respiratory tract so you should wear a mask and gloves every time you touch fiber. After a period of use, the fiber becomes brittle and deteriorates.