• Thomas R. Hay, Ph.D., P.E

Fiberglass Tank Inspection

Updated: Feb 26, 2020


Fiberglass tanks are complex structures made from multiple layers of different materials to achieve a balance between strength, weight, and corrosion protection.  Starting from the inside – out, a typical filament wound fiber reinforced plastic (FRP) tank consists of an inner surface, interior layer, structural layer, and outside layer.  The inner surface is commonly 10-20 mils thick resin rich layer. The interior layer is in the 100 mil range and contains 20 to 30 % chopped glass for strength. As its name implies, the structural layer carries most of the product related stress and contains 60-70% continuous strand filament winding. The outside layer is a resin rich surface layer with added coating(s) for ultraviolet protection and corrosion resistance.