Abstract: Coiled valve metal mesh of great void fraction and lengthy dimension and having a continuum of interconnected metal strands is coated with an electrocatalytic coating from liquid composition. The coating operation proceeds by contacting the mesh with liquid coating composition while the mesh is maintained in coiled form. This highly efficient coating method is continued through a curing operation while further maintaining the coated mesh in coiled form. Pretreatment preceding coating operation, e.g., degreasing and etching, may also be accomplished without uncoiling of the mesh. The coated mesh can later be uncoiled and current distributors welded to it for use as an electrode, e.g., in cathodic protection.

Abstract: An active metal coating which lowers the hydrogen discharge overpotential at the cathode in the electrolysis of aqueous alkali metal halide solutions is deposited on the cathode tubes of a cathode can of an electrolysis cell without the removal of the tubes from the can. Plating solution and anodes of plating metal are placed inside a cathode can and the components are electrically connected so as to deposit an active coating onto the cathode tubes. The plating metal is preferably an alloy of nickel and zinc and the process involves the final step of leaching the zinc component of the alloy deposit from the plated cathode tubes to provide a porous, active nickel surface which results in a reduction of the hydrogen discharge overpotential for the electrolysis of alkali metal halides, particularly sodium chloride.