ASTM C1257-15 PDF Download

The ASTM C1257-15 standard is a test method used to determine the resistance of solvent-release-type sealants to laboratory accelerated weathering. The standard acknowledges the difficulty of establishing a precise correlation between laboratory accelerated weathering and natural weathering due to geographical and local weather variations, as well as material-dependent acceleration factors. This test method aims to compare the weathering performance of a sealant against a control material with known outdoor weathering performance.

The test is conducted using aluminum channels as substrates, although it is noted that different substrate materials may yield different results. The standard includes two laboratory accelerated exposure procedures to predict the effects of ultraviolet or ultraviolet/visible radiation, heat, and moisture on color, chalking, cracking, and adhesion of the sealants. Additionally, it is stated that there are no comparable standards published by other organizations.