A beef tallow derivative, this material is really about the best release agent for making plaster molds, or plaster castings from plaster molds. Also finds use when making cement castings from plaster molds.
To use, Stearic Acid must be diluted with kerosene. Simply melt the Stearic Acid like you would a wax and add 1 part stearic to 2 parts kerosene by volume. Mix thoroughly and use either warm or cold. (It is usually best to warm your kerosene by setting your container in a bath of warm water before adding the Stearic Acid.) When warm this material is a liquid. When cooled, it is much like a paste wax. Also referred to as stearine.