Abstract: The edges of a porous substrate plate used in a fuel cell power plant are densified by impregnating a suspension of finely divided material in the interstitial spaces in the plate edges. The suspension, in the form of an "ink" is forced into the plate edges via a pressure differential applied through the plate between two press blocks. The ink is forced into the plate after a catalyst layer has been applied to one surface of the substrate plate. The ink thus penetrates to the inner surface of the catalyst layer, and also forms an integral filler band outwardly of the catalyst layer, which filler band has a top surface which is coplanar with the top surface of the catalyst layer. After the impregnation step, the seals are dried to form a dense low porosity border on the substrate plates which will fill with electrolyte to form a wet seal that prevents gas crossover through the edges of the substrate plates.

Abstract: Water is fed into the fuel cell stack in the hydrogen reactant stream. Some of the water is evaporated in the cells to cool the stack, and some of the water migrates through the stack from cell to cell. The water migration is the result of the water being dragged from the anode to the cathode through the electrolyte membrane and by the use of porous hydrophilic separator plates being interposed between adjacent cells in the stack. Water is forced through these porous separator plates by means of a reactant pressure differential maintained between the cathode and anode. The anode support plates provide a large surface area from which water is evaporated to perform the cooling function.

Abstract: A nail-like fastener having a substantially rectangular washer adapted to permit overlapping vertical stacking of a number of fastener/washer assemblies for use in a fastener driving apparatus of the type including a piston. The washers each include two substantially U-shaped recesses or cut-outs disposed one each near the midpoints of the top and bottom washer edges, such that the bottom fastener of a stack may be fired from the driving apparatus without disruption of the remainder of the stack.