Technical Aspects of Turtle Tank FRP Laminates
Fibreglass Reinforced Polyester tanks require four layers to make a long lasting vessel.

The laminate should consist of the following layers:

A) Interior chemical-resistant layer which acts as a primary barrier and contains no glass.

B) Interior anti-wicking layer which ensures there is no glass that is exposed to the sewage. If a glass fibre is in contact with fluid, capillary attraction will draw the liquid the full length of the fibre thereby compromising the structural integrity of the vessel.

C) Structural layer to fend off compressive forces of burial.

D) Exterior surface layer to prevent chemical attack from tank periphery and provide exterior antiwicking barrier.