Organic coatings: Exposure to water of low conductivity (NT POLY 162)

Abstract

  This Nordtest method is an accelerated laboratory test for assessment of the ability of organic coatings to resist degradation by blistering. The method is applicable to paints/coatings applied on steel structures and exposed to low conductivity water. Test equipment, preparation of test specimens and the test procedure are described. The test specimens are exposed to distilled water with a conductivity less than 1 mS/m at a constant temperature of 40,0 ± 0,5 °C. Assessment of the corrosion protective ability of the organic coating is based on visual examination of exposed test specimens with respect to blistering and rusting according to ISO 4628-1982, microscopic investigations and adhesion measurements according to ISO 4624-1978. The method has been found to be valid for evaluation of organic coatings applied on steel and exposed to fresh water and cold humid air.