Polyurethane coatings are used today as architectural coatings, product finishes, automotive coatings and industrial maintenance coatings, making them among the most versatile coating types available.1Polyurethane topcoats were introduced to the industrial maintenance and marine market in the mid-1970s as part of a corrosion protection system. The topcoat provides excellent weathering properties, i.e., good gloss retention and non-yellowing characteristics upon exposure to sunlight. When used in a basecoat/clearcoat combination, the weathering performance has been reported to be outstanding.2-3 They can also be formulated to provide good abrasion resistance, hydrolytic stability and resistance to a variety of solvents and chemicals. Polyurethane topcoats have evolved over the years into a coating technology that can be formulated to give low-VOC coatings, productivity-enhancing coatings,4 and long-lasting, cost-effective coatings.While still called polyurethanes, they can be inferior in performance to the original standard established in the 1970s.