Staining From Flashing and Surfactant Leaching

Chemical extractives in wood react with metal flashing and produce a stain below the flashing.  Stains can also occur in other areas where the wood surface is in contact with metal;  outdoor faucets, air conditioners, and conduits, for example.

Solution For Flashing Stains

Chemical extractive stains normally can be removed by washing with a mild solution of houshold detergent and water.  Fill any cracks between the flashing and a wood surface with a top quality acrylic or butyl rubber caulk to prevent the stain from recurring.  After the surface is dry, coat with a clear wood finish or other coating or stain.

Surfactant Leaching

All latex paints contain detergent like substance called surfactants.  There are necessary to the paint formula and are used in the process of making paint.  Under certain curing conditions, such as low temperatures or dondensing moisutre, a leaching process occurs which results in a buildup of surfactants on the surface of the paint film.  Surfactants are not part of the paint film, and their coming out of the paint film does no harm to it whatsoever.  In most cases, these substances come out of the paint film slowly and are often washed away undetected.

Solution For Surfactant Leaching

Most often, weathering removes the visible film of surfactant from the surface.  The sheen and colour are then restored.  If washing is necessary (for example, in areas protected from the weather) it should be done only after the surface has cured and well before condensation in the evening can occur.  To hasten the washing process, spray with a fine mist from a garden hose.  The best solution is to do nothing and let nature take its course.  The surfactant does no harm and time will correct the problem.

Rick Anderson Vancouver’s Best Painters www.vancouversbestpainters.com local: 604-PAINTER or toll free from anywhere in North American 1-800-PRO-PAINTER