|
"The bi-axial fiberglass "drapes" nicely over compound curves.Staggering consecutive layers of the cloth's bias of weep and woof builds tensile strength.----------- Epoxy has advantages over polyester although you need to look at price."
Bi-axial usually refers to rather stiff cloth made by sticking together two layers of uni-directional. Woven cloth, such as the extremely common 6-oz "boat cloth" is usually equally strong in two directions. For extra conformability and resin content, satin types are available. Really good work is often built up from layers of unidirectional cloth, set in the most advantageous orientations. Anisotropy is seldom optimum, but you can get it with tri-axial cloth, or by alternating layers of cloth (with equal thread count in the warp and weft) set square and at a 45 deg. angle. ("on the bias")
Epoxy usually takes far longer to soak into the cloth, and far longer to sand. Vinylester has similar physical properties when cured, but is easier to work with, except for the short shelf life which means it is only available from high-volume users or dealers. Vinylester is also more flame retardant. For a price, you can get some very superior resins, but they are not needed for bodywork.
|