A golf ball is formed including a core and a cover. A microwave source generates microwave energy including orthogonal linearly polarized components into the oven cavity from a port formed in a first one of the oven walls. Each recess has a corresponding clip which extends from one edge of the recess above the unitary surface to form a gap between the clip and the unitary surface. The truss may be wholly supported by the load-bearing interface of the top chord.