Auto body repair & detailing: stress crack in paint on roof, stress cracks, fiberglass roof

Question
I just purchased a 2002 ford ranger which has a fiberglass roof was told it has stress cracks in the paint do to someone placing a heavy object on it the fiberglass does not seem to be damaged how do I repair the the cracks they are not very wide just hair line that go across the roof can it be repaired and what do I need

Answer
Cracks in fiberglass toppers are vert common, and have less to do with abuse and more to do with shrinkage or stresses within the fiberglass itself. Fiberglass repair is a pain in the ass. If it's only in the gel coat, you can dish out the crack with some 150 on a DA sander, and spray in some marine gel coat repair material until it's back up to grade. Block sand the gel coat to flatten it, and re-apply if it still has low spots. If the cracks go clear through, the crack must be fiberglassed and matted from the inside, then the face coved out all the way through the crack, then matted and fiberglassed on the outside. If all this sounds a little Greek, then have a pro do this. I can't teach you fiberglass repair, then painting, in an e-mail. You will need to purchase literature online for that. Bill