Can the Service Life of Bonds Be Predicted?

The need for a method of predicting the service life of any glued product in a particular application from a few weeks or months of laboratory work is indicated. The problems of making such a prediction are briefly reviewed. The results of accelerated weathering tests are compared with the results of ten-year exposure tests of phenolic-bonded Douglas-fir plywood. Four strengths of phenolic bonds from stronger than the wood to weaker than the wood are included. It is shown how this information can be used to predict the service life of painted and unpainted plywood exposed to the weather. The prospect for extending the system to predict the service life of any glued product for any specified use is discussed.