A Laser Interferometric Study of Corrosion of Coated and Uncoated Metals I. — Technique Standardization with the Zn/ZnSO4/Zn System

Abstract A laser interferometric method of detecting holidays in and evaluating the corrosion protection of epoxy primer or other coatings was tested in the well known system Zn/ZnSO4/Zn. An electrochemical potential in the general range of corrosion couple values was applied, first to uncoated electrodes, then to coated anodes with measured, prepared holidays. The method is shown to give easily interpretable, visually obvious qualitative results. General methods of calculating good relative values and less accurate true values of corrosion currents are evolved.