NOVELTY - A manifold seal system comprises a rigid dielectric strip at an interface between a manifold contact surface and a corresponding fuel-cell-stack-assembly sealing surface. The rigid dielectric strip may be angled for a corner seal, or flat.    USE - The seal system is used for sealing fuel cell manifold to fuel cell stack assembly. It is useful for vehicular applications.    ADVANTAGE - The inventive seal system provides a stable seal and a constant sealing load that reduces compressive creep.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (A) a fuel cell assembly comprising fuel cell elements extending under compressive pressure between a pair of endplates to form a cell stack assembly and having mutually uneven surfaces at their ends thereof to which a reactant gas manifold (30) is to be sealed, a first seal part comprising at least one type of elastomer applied to the mutually uneven surfaces, a groove (24) disposed within a contact surface of manifold for receiving an elastomer gasket (15), a notch extending from a surface of each endplate for receiving an end portion of a rigid strip coplanar with the endplate surface to form a sealing surface of the stack assembly coextensive with and facing the manifold contact surface, a second seal part comprising an elastomer gasket disposed within the groove of manifold, and a third seal part comprising a rigid dielectric strip (40b) interposed between the first and second seal parts; and    (B) a method of sealing a contact surface of a reactant gas manifold to endplates and fuel cell elements of a fuel cell stack assembly by forming a groove in the contact surface of manifold, providing an elastomer gasket disposed within the groove, providing a notch in a surface of end plate for receiving a rigid dielectric strip coplanar with the endplate surfaces to form a sealing surface of stack assembly, applying elastomer layer(s) to the regions of fuel cell elements that are to be sealed to the manifold to provide a smooth and flat surface, adhering a rigid dielectric strip to the elastomer layer, and installing the manifold on the fuel cell stack assembly so that its entire contact surface is in direct contact with the sealing surface of stack assembly, with the rigid strip being between the manifold and silicone rubber layer.    DESCRIPTION OF DRAWING(S) - The figure is a close up view of a corner section of a seal system.    Gaskets (15)    Rubber filler layer (22)    Grooves (24)    Fuel manifold (30)    Air manifold (31)    Load cable (36)    Corner of cell stack assembly (37)    Rigid strip (40b)