What does moisture-related durability of wood bonds mean?

The accelerated test methods that distinguish between acceptable and unacceptable wood adhesives generally involve subjecting the bonded assembly to abnormally rapid and extreme moisture exposure or cycling. In the United States and Canada, these tests for moisture durability have been established, but selection of the appropriate test methods for the different service classes (extent of water exposure) is still being discussed in some cases. For establishing these standards, a better understanding of the information provided by these tests about the bondline durability is important. Most studies involve different adhesives with the same wood species and evaluate bond efficacy using strength and percentage of wood failure. We studied different wood species, especially in durability testing, to provide crucial insight into the factors that contribute to a durable bond and demonstrate the utility of the percentage of wood failure. The bonding and bond durability of white oak, sugar maple, aspen, Sitka spruce, southern yellow pine, and ipê are covered. The data indicate that the wood properties greatly influence the internal or interfacial stress and thus the durability of the bonded assembly.