Study of blister formation in GRP laminates in water

Glass fibre reinforced polyesters (GRP) are widely used in boat and swimming pool manufacture. One drawback for these materials is that they may develop blistering after prolonged and continuous contact with water. The aim of the research programme reported in this thesis is to understand the fundamental reasons for the blister formation, as well as the factors affecting it. Various polyester resins, epoxy resin, vinyl ester resin, different chopped strand glass mats (CSM) and initiators were used for GRP laminates and blister trials carried out. Blisters were examined visually and by an optical microscope; they are classified into four groups according to their origins: (1) contaminants, (2) bubbles, (3) pre-cracks, (4) glass fibre bundles. Detailed study of their relative importance shows that the last two categories are most significant. [Continues.]