Water Resistance Testing of Coatings in 100% Relative Humidity (ASTM D 2247)

Water Resistance Testing

Water resistance testing of painted or coated panels is accomplished by placing them in an enclosed chamber containing a heated, saturated mixture of air and water vapor. The temperature of the chamber is usually maintained at 100° F (38° C). At 100% relative humidity, a very small temperature difference between the specimen and the surrounding vapor causes condensation to develop on the specimen. Any effects such as color change, blistering, loss of adhesion, softening, or embrittlement are observed and reported. In a modification, TRL installed a cooling apparatus to the back side of test samples to insure significant condensation.

Water Resistance of Coatings Using Water Immersion – ASTM D 870

ASTM D 870 covers the procedure for testing the water resistance of coated specimens. Painted or coated panels are totally or partially immersed in distilled or deionized water in a corrosion-resistant container or tank. The water bath temperature is usually maintained at 100° F (38° C). The water is recirculated or aerated to prevent stagnation and oxygen depletion. Test panels are evaluated for blistering, softening, loss of adhesion, etc.

Reference: ASTM D 870 Standard Practice for Testing Water Resistance of Coatings Using Water Immersion