Selection of an adhesive for bonding FRP automotive panels

A four-phase programme was undertaken to evaluate adhesives for bonding fibre-reinforced plastic (FRP) to itself and to steel in automotive applications. Through initial screening of lap-shear specimens, four adhesives were selected from 17 candidates for bonding automobile hoods on a production-type bonding fixture. Evaluation of these sample hoods and of additional lap-shear specimens, including environmental testing, demonstrated the superior performance of a one-component urethane adhesive.A two-component modified epoxy demonstrated comparable performance on FRP to FRP assemblies, but not for FRP to steel applications.