AIC's 42nd Annual Meeting

Primers and paint make up the protective surface of most wood structures. It is often a struggle to keep paint from peeling, blistering, or lifting from old wood, in part because of changes in temperature and humidity, but also because of poor adhesion to an aged, weathered surface. A more durable coating can mean a reduction in maintenance time and costs, and often less wear on a surface due to less intervention.

This study examined the performance of latex and oil-based primers and a water borne wood stabilizer/conditioner using three commercially-available brands: Pittsburg Paints, Sherwin-Williams, and Zinsser. Benjamin Moore’s low lustre finish acrylic paint was used as the top coat in all but the trial that used an all-in-one primer and paint product. White top coat was used in all trials to eliminate color as a variable. The coating systems included one coat of oil-based primer with two coats of paint, one coat of latex primer with two coats of paint, one coat of wood stabilizer with two coats of paint, two coats of an all-in-one primer plus paint, and one coat of paint (without primer.) All coatings were applied by brush to salvaged, historic wood siding (approximately 70 years old). The wood was cut into 4.5 by 7.5 centimeter samples and any loose paint was removed from the samples using a simple paint scraper, followed by light sanding. Each coating was allowed to dry according to the manufacturer’s instructions. Four trials were conducted for each application. Surface properties of the samples were measured before and after artificial weathering using a QUV Accelerated Weathering Tester. Laboratory tests included the use of a gloss meter, colorimeter, Fourier Transform Infrared Spectrometer (FTIR), contact angle goniometer, and scanning electron microscope (SEM). In addition, 20 individuals examined the samples visually and provided opinions on the condition of the samples after artificial weathering.