Hotline Hi-Fire Shelf Primer is a kiln wash that has been developed to withstand the high kiln temperatures required for raking. A formulation of alumina and low-fluxing clays. Contains a dye which burns off when firing. Provides a smooth finish between the glass and kiln shelf. Can also be used for coating mandrels for bead making. Mix 5 parts water to 1 part primer. 1.5lb. container.