Abstract: A method of making molds which is easy, quick and can be accomplished at room temperatures and atmospheric pressures. The method includes applying at least one layer of gel to a male mandrel and curing at least one layer of polyester impregnated fabric to the gel layer. At least one layer of epoxy impregnated fabric is cured to the polyester impregnated fabric. At least one layer of plaster impregnated is cured to the epoxy impregnated fabric. At least one layer of epoxy impregnated fabric is cured to the plaster impregnated fabric. The resulting mold is removed from the male mandrel.

Abstract: A method of spraying fiber-containing fluids that results in smoother, more uniform coatings. The method comprises displacing a fiber-containing fluid through a nozzle assembly at about 69 KPa to about 386 KPa. The fibers have a length of about 1 mm to about 6 mm. The nozzle assembly comprises a nozzle extension, an elbow joint, and a nozzle in series communication through at least two hollow fluid passages. A first fluid passage exits at a first nozzle outlet having a diameter of about 2.5 mm to about 3.5 mm. A second gas passage exits at a second nozzle outlet and directs a gas at the fiber-containing fluid to atomize the fluid. Control means are disposed upstream of the nozzle assembly for controlling the fiber-containing fluid flow and the gas flow.

Abstract: A method of detecting cracks on the surface of an article after removal of a coating. A U.V. detectable compound is incorporated in a thermoset or thermoplastic grit blast media. A coated article is grit blasted to remove the coating. The surface of the article is exposed to U.V. radiation to detect grit blast media trapped in surface cracks. This facilitates the detection of surface cracks. U.V. detectable grit blast media is also used to provide improved coating adhesion. A U.V. detectable compound is incorporated into an abrasive mixture. A flow of the abrasive mixture is directed at the article to remove material from the surface of the article. The surface of the article is exposed to U.V. radiation in order to detect residual abrasive mixture on the surface of the article. Substantially all the abrasive mixture detected by exposure to U.V. radiation is removed from the surface of the article and at least a portion of the surface of the article is coated.