RE: all those fibers...
id say use carbon.. but i have no idea how to work it i just know its strong and light.....
as far as the fiberglass goes, epoxy can be light if you use it right, thin it out with some rubbing alchohol and just use enough to get the cloth wet(i assume u are using a cloth) then brush it smooth with a brush and let it dry, the other thing you could do is try fiberglass resin, it's made specificly for fiberglass, your hobby shop should cary it, if not tower does, and some other hardware shops might have it...
good luck