Abstract
Coating systems with ambient cure fluoro-polymer topcoats were developed in 1982 and have been applied to numerous steel structures since then. They have been demonstrated to give the best weathering performance among other commonly used topcoats. To confirm this, outdoor tests and accelerated weathering tests have been carried out. Gloss retention during exposure was measured, the surface appearance of each sample observed by SEM, and surface degradation analyzed by FT-IR spectroscopy. In addition, the extent of coating degradation by chalking was measured. It was observed that chalking of fluoro-polymer was much lower compared with that of coating systems such as polyurethanes, which means the fluoro-polymer coating retains its initial coating film thickness. Fluoro-polymer coatings have been applied to many steel and concrete structures, for example to high rise buildings and bridges where it is not easy to do maintenance. The results showed that the protective performance of the fluoro-polymer coating system was superior to other topcoats such as the polyurethane coating. Track records of fluoro-polymer topcoats were also studied and compared with laboratory testing.
