Use of Zinc for Cathodic Protection Available to Purchase

Zinc anodes have been used for perhaps 50 or 75 years in marine installations for preventing corrosion of propeller shafts in fittings on the stern of a boat. It is only in recent years, however, that the practicability of using zinc anodes in the cathodic protection of pipe lines has received much attention. Very little information is available in the form of technical publications dealing with the long-time performance of zinc anodes used for cathodic protection in different types of soil, and there appear to be no experience records which might be used as a guide in determining, for example, the ampere hour output which might be expected of zinc anodes for a period of 15 or 20 years or more. Some experimenters have reported the tendency of zinc anodes to become passive after two or three years action in the soil. In other cases the reports show satisfactory performance...