FINGER-JOINT STRENGTH EVALUATIONS OF 3 NORTHEASTERN HARDWOODS

A study was undertaken to evaluate the bending and tensile strength pe rformance of both vertical and horizontal finger-joints on three hardw ood species using a melamine formaldehyde (MF) and resorcinol formalde hyde (RF) adhesive. Tensile and bending strength results from small sp ecimen tests showed that neither finger-joint orientation nor adhesive had a decided influence on strength. Significant differences in bendi ng strength properties were measured in exposure test results; however , no clear patterns could be established. It was concluded from this s tudy that similar end-joint connections can be made using the horizont al and vertical orientation with either the MF or RF resin. Exposure t est results suggest that no immediate advantage is provided by end-joi ning red oak, red maple, and yellow-poplar with a more costly resorcin ol resin. However, additional test efforts are warranted to further qu alify the performance of finger-jointed assemblies for full-sized lumb er products under more severe test exposure conditions.