Moisture-cure urethanes put atmospheric and surface moisture to work (Reprinted from American Painting Contractor, March, 1998)

Moisture on a metal surface generally is considered a major problem for coa tings application, because it is a key cause of poor adhesion and other coa ting system defects. However, moisture-cure urethane coatings actually rely on atmospheric and surface moisture to form solid paint films. This charac teristic makes them very surface-tolerant. As a result, moisture-cure ureth anes are ideal for damp surfaces and low-temperature applications, extendin g the painting season for contractors and improving productivity by elimina ting downtime. Developed similar to 30 years ago, primarily for offshore ap plications, moisture-cure urethanes initially showed great promise. However , original formulations posed daunting limitations on recoatability and sta bility, and their high cost made the coatings impractical. Only in the past decade have technological advances made moisture-cure urethanes viable and valuable alternatives in the industrial coatings arsenal of corrosion prev enting weapons.