Epoxy products can be used to wet out chop strand mat, but there are a few very important things to consider with this application. There is a binder in chop strand mat that keeps all the little strands of fiberglass stuck together. Styrene in polyester and vinyl ester resin systems dissolves this binder and allows the mat to be wetted out very quickly and efficiently. Epoxy does not break down this binder, but can still be worked in between the strands. Therefore stiffer, heavier weight chop strand mat may be more laborious, or difficult to properly wet out. Chop strand mat wetted out with epoxy may also be much more difficult to manipulate for curves and bends for the same reason.