Visual Rating of Weathered Sealant Samples

Six sealant samples that had been weathered outdoors for 6.8 years in Japan as part of the SOPRO project (10-year outdoor exposure of 22 sealant samples at Hokkaido, Tsukuba, and Kyushu) were obtained from the Japanese delegation to ISO TC59/SC08. The samples were one-part polyurethane (PU1-1), two-part polyurethane (PU2-3), two-part silicon-modified polyether (MS2-11), two-part polysulfide (PS2-13), two – part silicone (SR2-17), and one-part silicone (SRI-20) sealants. The sealant samples were visually in­spected and rated by experts of the Japanese delegation for crazing, dirt pick-up, chalking, and color change. A scale of 1 (low/good) to 5 (high/bad) was applied for crazing and dirt pick-up, while a scale of 0 (no/good) to 3 (high/bad) was applied for chalking and color change. The perception of the direction of color change on the grayscale (darker or lighter) was also indicated. Table 1 shows the sample ratings based on the visual inspection.

Figure 2 shows photos of the sealant samples (strips) obtained from the Japanese delegation.

FIG. 3—Raw digital images of sealant samples (weathered and unweathered surfaces). Note: Width of sealant strip in Figs. 3-6 and 9: ca. 10 mm, thickness of sealant strip in Fig. 3 (left): ca. 5 mm.