For Best Results, Add Air Movement and a Little Heat
by Jamie White, PPG Segment Specialist
Is painting your sheds the bottleneck in your shop?
Do you wish you could move them out faster or put the roof on sooner?
Do you ever feel like you are just sitting around watching paint dry?
So what is the key to speeding up the dry time of your waterborne urethane and/or waterborne acrylic coating? The two main factors that affect the drying times of water-based coatings are cold temperatures and high humidity. Heat would seem like the best way to counter these two factors and it will definitely help, but it is not the most cost-effective tactic. The most efficient and cost-effective way to speed up the drying time of your shed coatings is air movement.
Water-based coatings dry via the evaporation of the water and solvents in the coating. When you spray a shed in your paint bay, you are not only coating the shed with moisture, you are also filling the air with moisture. This makes it difficult for the water in the coating to evaporate because the air is saturated with water.
To alleviate this, you can turn on fans pointed at the shed on multiple sides. This breeze across the surface will help draw the moisture out of the coating, which, in turn, will help it dry.
So what role does heat play? Generally speaking, heat is still important because the warmer the air is, the faster the coating will dry. However, it is not always easy to consistently and efficiently raise the temperature in your paint bay. If it is August in Alabama, you can just roll the shed outside after painting, but, if it’s winter in Minnesota, that approach will not work and heating can become costly. The good news is, if you can get your paint bay to 60-70°F and have good air movement across the coating, you will drastically improve your dry times. This, in turn, will help alleviate bottlenecks and make your production more efficient.
Take a look at the graphic. We have found this to be the simplest way to increase air movement around your buildings. By aiming two fans at opposite corners, you can create a breeze across all four sides. The larger the fans, the better. Try to keep the fans at a minimum of 3’ from the coated surface. If you combine this setup with the best heat you can provide, then you will see success. Make sure you speak with your PPG TrueFinish Specialist to check for proper application temperatures. In general, most water-based acrylic paints can go down to 35°F, but keep in mind that is generally meant to be the low temp and rising, not the high temp and dropping. Most water-based urethanes require 50°F and rising. You must also ensure that air is moving across all coated sides. Many times we see shops with a single fan mounted from the ceiling or only one fan available on the ground, which means only part of the shed is catching a breeze. Any dead area on the side of a shed will continue to dry slowly.
If you have any questions or would like additional information on this topic, please reach out to your local PPG Representative. GSCB
To better understand how to get the best coatings system, contact Jamie White ([email protected]), who will put you in contact with a PPG Truefinish Specialist in your market.