Abbots Frit L8 (Ca-Na-Bo-Si-Al)

Abbots Frit L8

High Alkali Frit is a ceramic material that contains high levels of alkali oxides, such as sodium oxide (Na₂O) and potassium oxide (K₂O). These frits are crucial in ceramic glazes due to their role in lowering the melting point of the glaze, functioning as a flux that promotes the melting and bonding of glaze ingredients during firing. This property is particularly valuable in low-fire and mid-fire ceramics, where achieving vitrification at lower temperatures is essential. Unusually, Abbots L8 frit also contains relatively high levels of alumina that help to stabilise the resulting glaze.

Thermal Expansion

High alkali frits have a significant impact on the thermal expansion of ceramic glazes. Alkali oxides tend to increase the thermal expansion coefficient (TEC) of the glaze and the frits are useful in developing crackle glaze effects.

The balance of alkali oxides with other glaze components, such as silica and alumina, is critical in formulating a stable glaze with the desired thermal expansion properties.

Safety Note

While high alkali frits are generally considered safe once fired, care should be taken when handling them in their raw form. Inhalation of fine frit particles can be harmful, so appropriate protective equipment, such as masks and proper ventilation, is recommended. Additionally, glazes containing high alkali frits should be tested for leaching, particularly if intended for use on food contact surfaces, as high alkali content can affect the stability and durability of the glaze in contact with food and liquids.