The test methods for laboratory evaluation of paint coatings are used despite well known problems of interpretation of data and lack of correlation with practical experience. Our laboratory is trying to develop a test method based on electrochemical impedance, to be used as a method for the routine evaluation of commercial quality protective coatings. Important impedance parameters included the low-frequency impedance magnitude, costing resistance, and breakpoint
frequency.
Keywords: Potable water, anticorrosive coatings, corrosion, vinyl coatings, electrochemical impedance, capacitance, high frequency.