Thermostone is one of the important materials which have been spraying glazed using different glass
mixtures based on alkaline (A5), lead glasses (A4) and their composition at different glass/water (G/W)
ratios using a special holder have been designed to keep the glazing on top of thermostone and thereby,
protect the other surfaces from damage. Physical and mechanical properties, color, roughness and
other properties have been investigated with the aid of microscopic analysis. Duplex layers of A5-
glazed layer on pre-coated A4-layer (total thickness of 1.4mm) proved their superiority among A4-
glazed layer (0.2mm) and unglazed surfaces, especially those glazed at G/W ratio of 30/70 where the
standard thickness (1.5mm) for glazing of pours bodies due to the action of composition of A5- glaze
mixture and its effects in sealing the pores and thereby, improving all the properties. The glazing
process in this study introduced a glazed thermostone with improved properties using spray technique
by means of compressive strength ,porosity, hardness , water absorption and bulk density aspects.