Degradation of Gel-Coat Layer in Glass/Polyester Laminate in Seawater Environment

摘要

Glass/polyester laminate coated with gelcoat layer of different thickness 0,5; 5; 3 mm was studied in terms of blistering behaviour and water sorption in hot water environment. Blistering was found to be accelerated for thin (0,5 mm) gel-coat layer compared to the thick (1,5; 3 mm), however no significant difference in blistering behaviour was observed between the laminates with gel-coat thickness 1,5 and 3 mm which may suggest that increasing the gel-coat thickness is effective only to a certain thickness limit. Microscopic studies demonstrated that blistering behaviour was related to the formation of subsurface cracks - longer and less densely distributed in thin gel-coat layers in contrast to numerous small cracks formed in the thick gel-coats.