ASTM C538-83(2004)e1

1.1 This test method covers only porcelain enamels containing the cadmium-sulfide or cadmium sulfo-selenide types of pigments. The purpose of the test is to detect those red, yellow, orange, and some green porcelain enamels that are likely to experience appreciable color changes upon exposure to atmospheric corrosion.

Correlation between results of this test and outdoor exposure tests of porcelain enamels colored with cadmium sulfo-selenide pigment shows that the cupric sulfate test is an effective indicator of the tendency for such coatings to experience appreciable color changes during weathering. The cupric sulfate test is considered useful for specification acceptance, quality control, and research and development purposes.