I had a chance to work on an old Top Flite Corsair. The plane was primed and painted, no fiberglass. The plane was probably 10 years old and really looked it's age. Just about every square inch of the thing had hairline cracks along the grain and some were even pretty big. If he would have put a light layer of glass on the plane before paitning the cracks and splits would not have occured. Sure it would have weighed a bit more, but the finish would have lasted. There are quite a few planes that I have seen that are clear monokoted and then painted over.