Because fiberglass reinforced plastic is a corrosion-resistant, plastic resin material. Some manufacturers of steel underground storage tanks have adopted the practice of coating the exterior of their tanks with a thick FRP coating. Tanks so coated are referred to as composite tanks or clad tanks.
There is also a process for lining the interior of underground tanks, and the bottoms and lower interior walls of aboveground tanks, with a protective mixture of resin or epoxy/fiberglass.
See also Tank and Tank lining.
