Polyurethane and UV protective coatings

Overview

Why the topcoat matters

Sunlight breaks coatings down. Epoxy is hard and protects steel well, but in the sun it chalks, fades, and yellows. A UV stable polyurethane doesn’t. Put over epoxy, it keeps the system’s color and gloss, resists abrasion and chemicals, and shields the layers underneath from UV. That’s why most outdoor steel systems end with one.

What it goes on

Tanks, cooling towers, pumps, wellheads, generators, rooftop equipment, structural steel, and any other metal that sits outside. We’ve put polyurethane topcoats on CNG tank clusters for UPS in Ontario, on the support beams and pipes of rooftop cooling towers at JC Penney stores across California, and on wellhead pumps at Wellhead Electric’s Delano Power site, where the old coating had peeled and flaked after years in the sun. At UCLA, the rooftop exhaust pipes and air handlers got an epoxy base coat and a UV protective high-solids polyurethane topcoat.

Finishes and colors

Polyurethane comes clear or pigmented, from matte to high gloss. It can match your colors, your brand, or your safety color codes. On Treasure Island in San Francisco Bay, a steel statue was finished in metallic silver polyurethane over a direct-to-metal primer, for corrosion and UV protection in constant humidity.

Moisture-cure urethane for damp conditions

Moisture-cure urethane is a polyurethane that cures with the moisture in the air. It tolerates damp surfaces and humid weather better than most coatings, and it stays flexible as the metal expands and contracts. It cures above 35 degrees Fahrenheit, more slowly in the cold, which makes it useful on tank exteriors, on the coast, and anywhere conditions are hard to control. It’s often applied over an intermediate coat with micaceous iron oxide (MIO) for more chemical resistance.