Soda Ash or Sodium Carbonate is a chemical with a variety of uses. These include uses within the pottery industry as well as various other industries. Its primary use within the pottery industry is as a deflocculant, reducing the viscosity of the clay slip. This allows the clay to be more easily poured and manipulated without increasing the water content of the slip.
It can be used in combination with Sodium Silicate to help create a casting slip with the required properties for casting. Both of these chemicals allow the viscosity of the slip to be controlled. This ensures the slip can be poured as required.
Soda Ash is also used for soda firing. This is a process where soda ash is introduced into the kiln in order to create visual effects on the finished piece.