Biaxial fiberglass is a type of fiberglass fabric where the fibers are stitched together in two directions—typically at +45° and -45° angles or 0° and 90°. Unlike woven fiberglass, the fibers in biaxial cloth are not interlaced, but rather laid flat and stitched, which improves strength and drapability.

The number refers to the weight: 1708 is 17 oz stitched fabric with an 8 oz chopped strand mat backing. 1808 is similar but with 18 oz stitched fabric. The mat backing improves bond strength with polyester resin.

Unlike woven cloth, biaxial fiberglass is stitched, not woven, so it lays flatter, wets out faster, and provides superior load distribution without crimped fibers.

Yes, you can use epoxy resin with 1708 biaxial fiberglass because it has a stitched mat instead of a chemical binder like chopped strand mat.

1708 weighs about 2 lb per linear yard. The number describes the build: 17 oz biaxial glass stitched at plus and minus 45 degrees, backed by a thin chopped strand mat. The mat face bonds down into the layer beneath it, which is why 1708 is the go-to single-ply reinforcement for transoms and stringers.

To wet out a full 50" wide yard of the 1708 biaxial fiberglass you'll need about 30oz of epoxy resin. This is a thick layup with stitched core and mat, which yields a strong result.

Biaxial fabric works well with polyester, vinyl ester, and epoxy resins. Be sure to choose the right resin system for your project and material compatibility.