This page outlines the fiberglass basics for boat construction and repair.
Fiberglass has many characteristics that make it an ideal material for use in boat construction.
What is commonly known as “fiberglass” is actually a combination of a resin and a glass or composite fiber. The resin is usually a two-part epoxy mixture or a two-part polyester mixture. Each has its strengths and weaknesses. The fiber (or cloth)is encapsulated in the resin layer, giving it additional strength. Depending on the type of work to be done, the fiber can be applied from spools (as in pipe construction), hand-layed in cloth mats, or applied with a “chop-gun”. Use of a chop-gun and hand-layed are the two most common methods in boat construction. Fiberglass boat repair is almost entirely accomplished by the hand-layed method.
For non-structural repairs and where filling or fairing are needed, often additives are added to the resins before they cure to adjust the consistency or other working characteristics of the resin.