A contractor had a problem with paint peeling off an exterior wooden structure. The paint's Pigment Volume Concentration (PVC) was a prime suspect. In order for a paint to have good resistance properties, the resin phase must be continuous. In other words, it must completely surround the pigment. As the pigment volume concentration goes up, there comes a point at which the resin no longer completely surrounds the pigment, called the Critical Pigment Volume Concentration (CPVC). CAS-MI was able to use a new, very fast electrochemical technique to prove that the paint was indeed over its CPVC, resulting in poor weathering resistance properties.
