Maybe if you douse it with gas and light it on fire, but I've never heard of fiberglass melting in the sun, if any thing, it would help cure the parts. The only way that could remotely happen is if you left acetone in the plane and let it sit in the sun baking with acetone vapors building inside. The fiberglass is just the right thickness, not heavy nor paper thin, with plenty of wood formers inside. My wing is built up and not foam core and it's covered in regular iron-on film, not solartex.