Metal Finishing Guide Book

2012 Organic Finishing Guidebook Issue

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The advantages of high-solids polyurethane, moisture-cured industrial coat- ings with less than 420 g/L (3.5 lb/gal) VOCs are the following: (1) This is a sin- gle-component system, hence no pot-life limitations. (2) It has all of the advan- tages of two-component polyurethane coatings. (3) It achieves chemically resis- tant properties more quickly than some two-component polyurethanes. (4) It is readily available in military camouflage coatings complying with MIL-C-53039. Disadvantages are the following: (1) This is a technology with less field history than two-component polyurethanes. (2) Currently only a few companies supply military-specification-approved camouflage coatings. (3) They are not yet avail- able in wide range of colors or in small quantities and may have a limited shelf life (less than 1 year). (4) They are very sensitive to moisture contamination, therefore requiring a special effort to keep moist air from the packaged or stored coating. (5) Drying time is affected by moisture in air. In very dry climates, the drying time may be longer than usual. (6) Currently they may be more expensive than two-component polyurethanes, with an average cost greater than $25/gal. (7) They have other disadvantages of two-component polyurethanes. Typical polyurethane end uses are the following: Aircraft skins Missiles and other aerospace products Over-the-road trucks Buses Rail cars Automotive refinishing Automotive (original equipment manufacturer): newly introduced high-gloss clear coat over metallic base coat; chip-resistant primer surfacers; flexible coatings for plastic facias bumpers Military ground support equipment, such as tanks personnel carriers,vehicles, with resistance to live chemical agents (chemical agents-resistant coatings) Architectural and Maintenance Structures and vessels in chemical plants Offshore drilling rigs Roofs Antigraffiti Pipelines Product finishing Machine tools 71

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