Senior scientist, American Plywood Association, Tacoma, Wash.
Pages: 40 Published: Jan 1982
As part of a program to develop performance standards for finishes on plywood and composite sidings, 36 trade-sales finishes were applied to Douglas fir and southern pine veneer-flakeboard composite panels, and specimens were exposed outdoors at three diverse geographic locations. The same finishes were also applied to selected specimens of rough-sawn southern pine plywood and exposed to a laboratory weathering cycle. Excellent correlations were obtained between the outdoor and laboratory data for erosion, flaking, cracking, and face-checking. The laboratory weathering method provides an effective short-term test for identifying those finishes with poor or marginal durability, and it also provides data which can be used to estimate the durability of better finishes. Finish durability is shown to be related to film elasticity, hiding power, and thickness. Elastic finishes with good hiding properties provided the best performance, while those finishes which are brittle, have a poor bond, or are poor in hiding power tended to be less durable.
organic coatings, artificial weathering, composite panels, cracking, Douglas fir, durability of finishes, erosion, face-checking, film elasticity, film thickness, flaking, hiding power, house paints, outdoor weathering, performance standards, plywood siding, southern pine, stains, ultraviolet radiation
Paper ID: STP33763S