A watertight seal is provided between a pair of components by providing a clearance between studs on one of the components and holes on the other. A non-conductive bushing is located in the void between the stud and hole and has a flange at one end. A first pair of resilient gaskets is located on opposite sides of the flange. A rigid washer overlies one of the resilient gaskets and a further resilient gasket is located on the opposite side of the washer. A nut having a blind bore extending from an end face is threaded to receive the stud and an O ring is located on the fastener between an end face of the nut and the second resilient gasket to effect a seal therebetween. Upon tightening of the nut on the fastener, the gaskets are compressed to provide a seal between adjacent surfaces and the bushing maintains the fasteners spaced from the holes.