How are Elastomeric Coatings used?
We often need to protect steel from the elements and from temperature swings. Elastomeric coatings fit the bill quite nicely. The best brands, such as FX-501M from Fox Industries, are made from 100 percent acrylic polymer, which is a long chain of acrylate or methacrylate molecules. The polymer is waterbased and forms a tough, corrosion-protective film on metal. Other ingredients are added, such as diphenyl ketone (a UV-ray protectant) ethylene glycol (an anti-corrosive), and coloring agents.
Elastomeric Properties
Elastomeric coatings are flexible, so they are well suited to protecting metals that expand and contract with changing temperatures. The flexibility is inherent in the acrylic backbone and will not leach out over time. This allows elastomeric coatings to bridge cracks without suffering from wrinkles or ruptures. The coatings are made to be UV stable, resistant to dirt, and remain effective in lower temperature applications. You can apply these coatings to raw or rusted steel as long as the metal is sound and the environmental conditions are not too severe. You can also apply them to concrete.
FX-501M has a high tensile strength of 135 psi @ 75°F, and elongates 450 percent before breaking. It dries to the touch in one hour, is hard dry in six hours and fully cured in seven days. The satin surface finish can be colored in a variety of light earth tones. It is not combustible and strongly adheres to its substrate — adhesion is 300 pounds per square inch.
Advantages Of Elastomeric Paint
We like using elastomeric paint for a number of reasons, including:
- Resistance to water, sunlight/UV, acid rain and salty environments
- All-temperature flexibility
- High strength
- Suitable for roller, brush or spray application
- Easy to clean up because its waterborne
- Retains its color and finish
- Self-priming and doesn’t require extensive preparation of rusted steel
Elastomeric Application
Some surface preparation is required for elastomeric paint. Surfaces should be dry, clean, oil- and grease-free, and free of loose rust or loose previous coatings. These can be removed with a power washer delivering at least 4,000 psi at a distance of four to eight inches. The application temperature range is 40°F to 100°F, but in all cases, the surface should be 5°F above the dew point and the relative humidity should not exceed 80 percent. We apply two coats with total thickness of at least 14 mils. The second coat can be applied after about four hours, depending on the weather conditions. Coverage area per gallon is 120 square feet per coat.