Finish Too Thick?

Oil Modified Polyurethane

The viscosity of the finish is critical to good finish application. The single biggest factor which influences the viscosity of the finish is

temperature. As the temperature decreases, the viscosity of the finish increases. Under very cold temperatures (<50° F) the finish can seem as thick as molasses! This will affect drying, hardness, leveling, coverage, de-foaming, and the sheen of the finish.

It is important to bring the finish to approximately 70-80° F. The finish is designed to work best at these temperatures. Also, check the temperature of the floor. As the finish is applied, it will soon reach the temperature of the floor.

Temperature & Viscosity

Under cooler temperatures the viscosity or thickness of the coating increases. This reduces the spread rate and dramatically increases drying times — sometimes doubling or tripling it. Due to its volume, it takes approximately 24 hours for the finish to reach room temperature if it has been stored outside (even longer for larger containers).

The graphs below illustrates the effects of film thickness on dry time of the finish. Lower temperatures will increase viscosity and reduce coverage significantly. As the coverage is reduced by thicker coats, dry times are drastically increased. The solution is to apply the finish at 500 sf/gal or 3 mil wet film thickness. PoloPlaz Super Dry will help under poor drying conditions, but will not help when heavy coats are applied.

Problem: Finish too thick.
Solution: Extended dry times.
Bring finish to 70 – 80°F.
Apply at 500 sf/gal.

Reprinted at Wood Flooring Guy with permission from Bill (National Sales Manager) at PoloPlaz ( Visit their site for more information.