Hi!
The easiest metode of laying down 25g fiber-glass is to just lay it down over the surface...then pour molding epoxy on (24 hour mold making epoxy no other epoxy) and spread the epoxy either with a thin brush or with a spreader. You can also use polyester resin. Flash and SIG makes spreaders.
This is so easy!!!
Using anything else than the above tools which are the best...you ain't got the right epoxy type!
The epoxy should be nearly as thin as milk and will satturate the fiberglass at once!
Do not use any hobby stuff epoxy for wing and fuselage coverings