When it comes to the success of surface coating applications, there is a lot of warranted attention on cleaning and preparation. Just as important, however, are the conditions when curing surface coatings. During the curing process, substrates and coatings remain vulnerable to ambient conditions. By controlling the environment as a coating cures, you’ll ensure the success of the coating application, meet the project deadlines and prevent premature coating failures.
Conditions to Control when Curing Surface Coatings
- Relative humidity: High relative humidity levels not only prolong curing times, but also affect the life and performance of coating materials. As coatings cure, relative humidity levels should stay below 85 percent. Bear in mind that some types of coatings require specific humidity levels to cure properly, so it’s best to follow the manufacturer’s specifications.
- Air temperature: In general, surface coatings dry the best when temperatures are between 56°F and 99°F. When temperatures are too cold, a coating may take longer to cure, which could result in re-work and project delays. Temperatures that are too high could cause the coating’s solvents to dry too quickly, affecting its future performance.
- Surface temperatures: Substrates respond to the environment around them. During the day, for example, a surface might absorb heat and become hotter than the air temperature, similar to a metal playground slide on a summer day. At night, a surface might radiate heat. When such temperature changes occur as a surface coating cures, condensation may form on a fresh coating.
- Dew point temperature: To know the best surface and air temperatures in which to apply a surface coating and allow it to cure, you must know the dew point temperature, the temperature at which moisture forms on a substrate. The best time to apply a surface coating is when the surface temperature is more than 5°F above the dew point temperature. It is a good idea to maintain these temperatures throughout the curing process using temporary humidity control solutions.
- Ventilation: When curing surface coatings, good air circulation is vital. In enclosed spaces, a forced ventilation system prevents solvent entrapment during the curing process.
- Wind: If you’re coating a surface exposed to the elements, wind might provide the necessary ventilation. To prevent accelerated solvent evaporation during the curing process, wind speeds should be no faster than 15 miles per hour. In high wind conditions, enclosing the area with a temporary shelter and using a forced air ventilation system will create an environment that’s more conducive to the curing process.
When curing surface coatings, a variety of instruments allow you to monitor the conditions at a project site, such as psychrometers, thermometers and digital dew point meters. Many contractors opt to use remote monitoring devices that work with Polygon’s temporary climate control solutions. The devices monitor and record the environmental conditions throughout the surface coating process, and provide alerts when conditions are not optimal. By pairing temporary climate control solutions with remote monitoring technologies, you leave nothing to chance during a project. Get in touch with a Polygon representative to learn how you can leverage these technologies to ensure the timeliness and success of every surface coating project.