Gelcoat Blistering and the Use of Glassflakes

摘要

Gelcoat blistering in glass reinforced polyesters (GRP) exposed towater is the most visible consequence of the osmotic process, a problemthat affects especially boat hulls and swimming pools, thus limitingGRP’s further development as an engineering material. Blistering canbe prevented by the addition of glassflakes in the gelcoat. Glassflakesact as a barrier to the water flow through the cast resin, lowering thepermeability of the gelcoat so that water no longer accumulates at thegelcoat-laminate interface. Accelerated ageing tests were performed,varying the specification of raw materials of the resin and weightfraction of the glassflakes. Results show that the preventive action ofthe glassflakes depends upon the combination of these variables. Someof the combinations enhanced the blocking effect of the glassflakes,presenting significantly superior performance in comparison withtoday’s standard.