Scope:

ASTM D6625 practice is used for evaluating the protective behavior of polish-coated paints, related coatings, and materials against degradation caused by heat, UV light, oxygen, and water. This practice is based on the test parameters as stated by ASTM G53. This practice provides basic principles and operating methods for using fluorescent ultraviolet (UV) and condensation apparatus. This practice does not imply a particular correlation with outdoor exposure.

Test Procedure:

For ASTM D6625 practice, the test is conducted using a fluorescent UV-condensation light and water exposure apparatus. The polish-coated coating is exposed to the apparatus that produces temperature variation, UV radiation, and water condensation for a predetermined time period. The polish application conditions are between 21℃ and 27℃. This property is assessed via a periodical gloss reading of the polished and unpolished area of the test sample. The exposure cycle is 4 h at 50℃ for condensation and 5h at 70℃ for UV exposure. The main factor that should be acknowledged when running the test is the amount of polish used on the sample.

Sample size:

The samples are used as specified by ASTM D6625. 

Data:

The end results are reported in terms of irradiance level and exposure cycle. 

Conclusion:

ASTM D6625 practice is used for evaluating the protective behavior of polish-coated paints, related coatings, and materials against degradation caused by heat, UV light, oxygen, and water.