Abstract: A spin coater suitable for spin coating spectacle lens molds with polymerizable coating composition. The spin coater includes a drawer which rotatably mounts at least one chuck thereon, which drawer is slidable between a front and rear position within a housing to sequentially allow application of a coating by the spinning chucks in the front chamber of the housing, followed by polymerization thereof in the rear chamber. Each chuck of the spin coater is provided with a mold seat defined by a ledge and adjacent lip, the lip automatically centering the mold in the seat axis by virtue of its dimensions in relation to the mold. The chuck also has a lengthwise resilient vacuum conduit, preferably in the form of a bellows, which has an open end which can sealingly engage against a seated mold, such that when a vacuum is applied through the vacuum conduit the mold is urged firmly against the ledge of the mold seat.