THE BONDED REPAIR OF FIBER COMPOSITES - EFFECT OF COMPOSITE MOISTURE-CONTENT

A study of the effect of pre-bond moisture on repair joints in carbon-fibre reinforced epoxy resin is described. The effect of pre-bond moisture on the strength of the joint and on the microstructure of the repair patch and adhesive are investigated. It is found that low levels of pre-bond moisture (below 0.5% w/w) have little effect on the repair strength or microstructure but that, as the moisture level increases, the repair strength falls. Since the moisture Levels usually found in composite components in service are typically 0.8% w/w, it is clear that complete drying before repair is not always necessary.