Sealing

Seal (188) for arranging between two electrically conducting constructional units (118, 120), especially between two constructional units of a fuel cell block composite, comprises at least one first component (256) made of an electrically insulating material and a second component (258) made of a material which is at least partly fluid at the operating temperature of the seal. During the operating state of the seal the second component lies in contact with at the most one of the constructional units. Independent claims are also included for an assembly group comprising the above seal arranged between two electrically conducting components, and a fuel cell block composite comprising at least one of the above assembly groups. Preferably the second component contains copper, silver or a copper and silver alloy. The first component is Al2O3 and/or porcelain.