A base plate of a disc storage system including an interior and an exterior surface, an entrance hole passes between the two surfaces and a groove surrounds the entrance hole and reduces the passage of air along an interface between the exterior and the interior surfaces. The groove may be in the shape of a circle or other alternative shapes such as a rectangle, as considered within the plane of the interior surface. An overmold is molded to the base plate and fills the groove. The plate is generally made of a plastic. The groove is amenable to the stamping process as well.