Fiberglass cloths, mats, and tapes are used to provide a great deal of the structural strength of fiberglass boats. The strands of the cloth provide tensile strength in the longitudinal direction of the strand. Layering these strands between layers of resin provides a durable material that can conform to nearly any shape and support great loads.
There is a wide variety of cloths, mats, and tapes available for nearly every conceivable application. Each structural repair will require at least one type of cloth.
There are several major categories of cloth.
Chopmat is made up of strands of fibers several inches in length that are layed in random directions. It does not have a great deal of strength in any single axis, but is relatively flat, and therefore good for the top layer of a repair.
Biaxial woven mat consists of a "checkerboard" weave of bundles of long strands of fiber. This type of cloth is provides more strength, as the strands are longer, and in two directions. This cloth is available in a variety of thicknesses and checkerboard sizes. Use the larger sizes for big areas that need a lot of resin contact. Use the smaller sizes for edges and random shaped repairs.Return to Fiberglass Basics from Fiberglass Cloths