Effect of excessive pretreatment of pine timber with CCA wood preservatives on the bond quality of PRF and TRF wood adhesives

The phenol-resorcinol-formaldehyde adhesive is suitable for use at all levels of CCA retention that were tested. Due to changes in retention during treatment, best results are obtained if the glue-spread rate is kept above the standard of 200 g/m², or control measures are taken to prevent the glue-spread from dropping below this level. The tannin-resorcinol-formaldehyde adhesive, without modification, unlike its performance in the manufacture of plywood, appears from these tests to be less suitable for use on treated timber from the view point of lowered percentage of wood failure.