Pete, I could be totally off here but unlike polyester/vynelester resins slow curing epoxy is pretty flexible for at least a day or two before setting hard. So bending a 1/8" sheet of fully cured polyester resin in woven roving doesn't sound doable but a single sheet of fully cured 6oz epoxied fiberglass is pretty flexible (it's thin). A thin layer of 4oz glass on 3mm or 4mm plywood where the epoxy is soft has no problem bending with the glass on the inside. It's doable, I've done it.