Woven roving fiberglass is a heavier fiberglass cloth with an increased fiber content derived from its continuous filaments. This property makes woven roving an extremely strong material that is often used to add thickness to laminates. Woven roving strength makes it a good choice for fiberglass boat hulls. It also wets out very easily, and is very strong when cured.
However, woven roving has a rougher texture that makes it difficult to effectively attach more roving or cloth to the rovings surface. The result would be a large number of voids that would require excessive amounts of resin.
To compensate, roving is generally placed in layers with chopped strand mat. This solution allows the roving/chopped strand mixture to be used for fabrication of large surfaces or objects.
Woven roving consists of glass fiber roving that is interlaced at a 90-degree angle to form a heavyweight fabric. In contrast, medium-weight CSM (chopped strand mat) consists of randomly laid fiberglass strands held together with a binder.
Super-strong fiberglass woven roving is often a key component of multi-layer lay-up operations such as boat hull construction. In contrast, chopped strand is rarely used alone, but is often used in conjunction with woven roving. CSM helps reinforce the laminate and decrease the amount of weave print-through.
Woven roving may be used with most types of resin systems. Chopped strand is compatible with polyester and vinyl ester resins, but is not formulated for use with epoxy resin systems.
Woven roving thickness varies by the fiberglass fabrics weight. Both of these fabrics are frequently used in construction and laminate projects.
18 oz. Woven Roving: Thickness = 1/32-inch.
24 oz. Woven Roving: Thickness is > 1/32-inch.
While woven roving is a type of woven fiberglass cloth, biaxial fiberglass does not contain any type of weave. Instead, biaxial fabric contains two layers, each situated at a 45-degree angle to the other. Rugged polyester yarn holds the two layers together.
Biaxial fiberglass cloths construction lets it conform to diverse directions and shapes, while woven roving is too bulky for that type of use. Compared to woven roving, biaxial cloth does not show much print-through and is a much stiffer material.
Typical fiberglass cloth is made of right angle-weave fiberglass strands, and is manufactured in varied thicknesses. Lighter-weight fiberglass cloth is ideal for creating complex layups and covering wooden surfaces. Heavier fiberglass fabric adds needed bulk and thickness to multi-layer laminates.
Woven roving is a rough-textured fiberglass fabric that is cheaper and stronger than conventional fiberglass cloth. However, its coarse weave makes it undesirable for use on high-visibility surfaces. Because woven roving lacks fiberglass cloths flexibility, it is not practical for use in curves or complex shapes.