Abstract: The corrosion resistance of waterborne and solventborne anti-corrosion coatings for transformers was evaluated using neutral salt-spray testing and a suite of analytical techniques, including electrochemical impedance spectroscopy, as well as measurements of gloss, hardness, and adhesion. Correlations between these coating properties and corrosion performance during salt spray exposure were analyzed. The results indicate that the waterborne coating experienced a sharp decline in performance after 360 h of neutral salt-spray testing, and almost completely lost its protective ability. In contrast, the solventborne coating retained significant protective function even after 1 440 h of testing. Throughout the test, coating gloss showed negligible change, indicating it is not a suitable criterion for determining coating failure. Conversely, coating hardness and adhesion exhibited a strong correspondence with protective performance. Furthermore, the low-frequency impedance modulus derived from electrochemical impedance spectroscopy alone did not accurately represent the coating's corrosion resistance and should be considered in conjunction with hardness and adhesion data for a comprehensive assessment.