While strolling through the big box store last week I spotted an inexpensive combination temperature and humidity gauge which leads me into our TECH TIP. Besides variations in the wet coating application thickness, humidity and ambient air temperature are two other factors that affect dry time. Chemists formulate air-dry coatings for application and drying between 65 and 85 degrees F.
High temperatures, especially when caused by direct sunlight, can lead to blistering. Which is a result of the wet media vaporizing, and building pressure under the paint layer until the wet paint bubbles away from the substrate? Lower temperatures especially those below the dew-point can result in defects during the coating drying process.
High humidity slows down the wet media evaporation rate because the air is laden with moisture resulting in the coatings wet media having little place to go. A humidity reading of 60% is okay, and 55% is better. Some of our customers use a de-humidifier to control their finishing room humidity.
You are wondering where are we going with this topic and the answer is; display a combination temperature/ humidity gauge in your finishing room and make a point to finish with proper room temperature and humidity to lessen the chance for defects in your finish.Handle: news/why-is-there-a-variation-in-my-coatings-dry-time