A fuel cell unit incorporates a pair of plates; one plate an anode, the other a cathode. Respective anode and cathode plates are physically bonded together to form such pairs; wherein pluralities of the pairs are secured together to form commercially available fuel cells utilized to generate electric power. Seals employed between respective pairs of plates are in the nature of resilient beads arranged about selected areas of the plates to confine paths for fluids adapted to flow within said selected areas. A combination sealing and bonding method for manufacturing such fuel cell units involves the injection of a rapidly curable liquid silicone into aligned mold gating apertures of the respective pairs of the plates, whereby liquid silicone flows through and between the plates to a) seal between respective anode and cathode plates pairs and to b) form an insulation layer on the backside of the anode.