Once a coating has been applied to a surface, a certain amount of time is needed for the paint to dry. Drying times can be greatly influenced by a number of factors and must always be considered in an industrial painting project. By carefully planning the painting schedule with built in dry times, the impact on production or facility use can be lessened.
So what affects drying times? The big three factors that influence the drying times of acrylic and latex paint are coating thickness, humidity and temperature. Let’s take a look at coating thickness first.
Thick coats always increase paint’s drying time. Acrylic and latex paints dry in a two step process. In the first step, the paint loses moisture through evaporation. Once enough moisture is lost, the paint develops a very thin skin of dried paint. Underneath this skin, the paint is still wet and is still vulnerable to damage.
In the second step of the drying process, the deep layer of wet paint hardens. During this step, the pigment is trapped within the lattice structure of the paint’s binder. Also during this stage, the polymers in the paint begin to cross-link, further increasing the paint’s durability.
The second step of drying can take several days to complete, and should be figured into project completion times to prevent damaging the fresh surface coat.
Coming Up: How Humidity and Temperature Affect Acrylic and Latex Paints