Surfactant Bleed

The Pacific Northwest's dew, fog and rain can present a peculiar problem to exterior surfaces freshly painted with latex paint. All latex contain detergent-like materials called surfactants.

Surfactants are necessary to:

· the process of making the latex as well as the paint;

· the stability of the liquid paint and:

· the application characteristics of paint.

Surfactants are not necessary to the dried paint film, and sometimes come out of the film over a period of time. When they are removed slowly by the washing action of rain, there is no problem. However, under certain environmental conditions present during and shortly after paint application, this process can occur rapidly, causing a building at the surface. This buildup can appear as light colored crystalline deposits or soft white, brown or clear spots. The usual cause is the occurrence of high humidity and low temperatures in the first few days after painting, particularly if condensation (or dew) occurs on the painted surface. It may also be caused by sprinkler water wetting the surface. The appearance of this phenomenon is most noticeable on medium to dark colors often because it is simply more visible and these colors usually have more surfactant in them.

The problem may often be corrected by simple rinsing with a hose, if caught before the sun bakes the deposit. It if becomes sun-baked, it may be necessary to wash with a household detergent solution and a soft brush. However, except in protected areas, rain will eventually remove the deposit.

WARNING: Never mix bleach with detergent containing ammonia, as fumes can be harmful or fatal.

Source: Miller Paint Product Information and Specifications Revised 2/93