RE: Sealing and Painting Balsa
Lately I've been trying silkspan or tissue applied with Sig Stix It instead of Nitrate dope. Stix it goes on nice and then you can iron whatever you want onto the surface. Then a couple pf coats of clear nitrate dope and you will have a light weight, stable, smooth surface to paint. If you want a glass like surface fill with nitrate dope and talc.
Need a lot more strength for not much more weight? Try Polyspan ironed on with Stix It. Much stronger than silkspan but also more expensive. On larger planes Sig Koverall works well and is not too expensive, apply with Stix It and seal with nitrate dope.
Fiberglass cloth and epoxy or polyester resin is just too messy and heavy for my taste. Been modeling for 40 years and never felt the need to try it more than once or twice, never turns out as nice as the traditional silkspan and dope.
Nitrate dope is compatible with just about anything, not so with epoxy or polyester resins. Plus nitrate dope ALWAYS cures, sometimes epoxy or polyester resins don't.