Definition - What does Pigment Overload mean?
Pigment overload refers to an occurrence in the process of coating a surface where significant amounts of insoluble coloring agents are present in the coating. These amounts are typically in excess of what is required for the given surface area of the metal to be treated. A pigment overload typically indicates that the coating specification was not adhered to, and may result in less than optimal corrosion protection.
Corrosionpedia explains Pigment Overload
Pigments are finely ground insoluble particles that are dispersed in a liquid coating to provide color and other desirable properties, such as opacity, durability and corrosion resistance.
Pigment application is guided by the critical pigment volume concentration (CPVC) of a specific pigment to be used. CPVC is the ratio of binder elements to pigment changes experienced on a metal's surface once the pigment has reached a maximum loading level with sufficient air concentrations present. It typically is between the 30 to 60% ratio ranges.