The Stonecast system expands the use of polyurethane into applications previously not practiced. It has a low coefficient of thermal expansion of most urethane molding compounds available. It is formulated to produce lightweight molded parts that can replace wood, fiberglass and metal in several indoor and outdoor applications. It can be attached to metal, concrete and wood without concern for expansion/contraction problems, warpage or cracking over a wide range of temperatures. It can be easily painted, stained, sanded and drilled, and does not require expensive equipment for processing. It can be used to produce one-piece finished products, which will replace parts that now use multicomponents. It also can be used with a variety of in-mold or post-finish coatings to obtain UV stability.