A method for manufacturing a shell mold intended for manufacturing at least one metal part by lost-wax casting, the shell mold including at least one molding cavity intended for molding the metal part, and at least one feed channel intended to convey a liquid metal to the molding cavity, the method including manufacturing a wax pattern including a part pattern intended to form the molding cavity and a feed channel pattern intended to form the feed channel, arranging at least one ceramic insert around at least a portion of the feed channel pattern, and manufacturing the shell mold around the wax pattern.

A composition includes a first layer of surfboard wax and a second layer of sunscreen. The second layer is adhered to the first layer so that the first and second layers are disposed above and below one another. The second layer includes a combination of a wax and an ultraviolet radiation absorber.