ASTM D2247 mentions the basic principles and procedures for testing the water resistance of coatings by exposing coated specimens to an atmosphere maintained at 100% relative humidity, causing condensation to form on the test specimens. It’s valuable for evaluating both individual coatings and complete coating systems. Tests conducted at 100% relative humidity are commonly used for specification acceptance, quality control, and research and development of coatings and substrate treatments. The ASTM D2247 test typically results in a pass or fail determination, although the degree of failure may also be measured. A coating system is deemed to pass if there is no evidence of water-related failure after a certain period.
ASTM D2247 Test Method
| Placing Specimens in a Heat Chamber | Coated specimens are placed inside a sealed chamber filled with a heated, saturated air and water vapor mixture. The temperature inside the chamber is typically maintained at 38°C (100°F). |
| Condensation | At 100% relative humidity (RH), even a slight temperature difference between the specimen and the surrounding vapor leads to the formation of condensation on the specimens. The duration of the test can be adjusted to vary the exposure condition. |
| Reporting Changes in Specimen Characteristics | Water permeates the coating at rates determined by the coating’s characteristics. Any effects, such as color change, blistering, loss of adhesion, softening, or embrittlement, are observed and reported. |