Water delivery in accelerated weathering testing of coatings for improved outdoor correlation

 
Accelerated weathering testing has been used for over a century to evaluate the outdoor performance of durable materials such as coatings. Research over the past several decades has demonstrated that many historical test standards were deficient in delivering water to test specimens, leading to their failure to reproduce water-based degradation modes. Several modern accelerated test protocols are now available that include a significant emphasis on water delivery, including EN 927-6 (fluorescent UV), ASTM D7869 (xenon arc , and ASTM G90 ?Spray-2,? (outdoor accelerated solar concentrator). This presentation will discuss the value of water delivery in accelerated weathering testing of coatings with respect to these international test standards.