Abstract: A method of applying a smooth thin waterproof coating on engineered particleboards including oriented strand boards, thereby permitting the use of such boards for applications wherein the boards are exposed to moisture, including, for example, foundation forms, roof sheathing, basement walls, etc. The method of this invention includes applying a thin liquid cementitious coating on a surface of an engineered particleboard having a moisture content preferably less than three percent, wherein the cementitious coating fills the interstices between the particles and coats the surface. The cementitious coating is then dried and the surface is abraded to receive a thin liquid curable polyurethane coating over the cementitious coating. Finally, the exposed surface of the polyurethane coating is heated to remove surface imperfections and cure the polyurethane coating.

Abstract: A method of filling an elongated generally lineal channel with polymeric resin foam, preferably polyurethane foam, using an application gun having a laser sight for accurately aligning the application gun relative to the longitudinal axis of the channel to be filled.