Abstract: A method of molding a hardened glazed surface on a building block where the block is provided with a slot in the surface to be coated includes inserting a boundary edge member through the slot after the block is placed in a mold containing the coating composition; the boundary edge member conforms closely to the shape of the slot; the molding composition is cured with the boundary edge member in place and the boundary edge member is subsequently removed by forcing the member into the slot, that is away from the surface on which the composition has been molded.

Abstract: A method of coating a surface of an article block includes utilizing a mold that has its interior surface electrolessly coated with a metal such as nickel where the mold is made from mild steel and further includes depositing a resinous composition in the coated metal mold and then inserting a surface of the article and then subsequently curing the composition by exposing the mold to heat; the exterior surface of the mold is oxidized and darkened to increase the capacity for the mold to absorb radiant heat; a method of preparing the mold is provided where the mold is electrolessly coated with the metal while the exterior surface thereof is masked to prevent the deposition of the coating metal on the exterior surface.

Abstract: Masonry blocks are provided with a cured resinous coating of an ethylenically-unsaturated polyester. The polyhydric alcohol in the ester is primarily neopentyl glycol to provide water resistance. The acid in the ester is isophthalic acid with 10 to 33% maleic anhydride, based on the total weight of the polyester. If the upper limit on the maleic anhydride is exceeded, stain resistance is lost. Triethyl phosphate is preferably incorporated to provide fire resistance while eliminating flame and smoke problems when employing methyl methacrylate as a polymerizable solvent. The sand-polyester compositions of the invention can also be formed as cast articles without a masonry unit backing.