Volume 21, Issue 4 (July 1993)
Determining Paint Adhesion to Wood Using a Uniform Double-Cantilever Beam Technique
Accurately predicting paint adhesion without the lengthy time required for typical exposure and evaluation is advantageous. Mechanical tests that use shear block, lap shear, or tensile specimens to measure paint adhesion result in large data variability, making it difficult to differentiate subtle changes in adhesive strength. The objective of this study was to decrease the variability of measured paint adhesion in fracture toughness tests. Preliminary and computer-aided experiments were conducted using uniform double-cantilever beam (UDCB) and shear block specimens. The coefficient of variation (COV) for the shear block tests was about 15%. The UDCB specimens cut from the same panels as the shear block specimens had a COV of 10%. Computer-aided tests of UDCB specimens gave a COV of less than 5%. Results show that using UDCB specimens with the aid of a computer is an excellent technique for determining paint adhesion to wood.