[400TT]

Merv, it's the heat cycling that's important. In my experience the white gel coat does not get hot enough. Put some black plastic on it etc and the amount of heat the body absorbs in many times greater.

The areas that usually cause the greatest area of concern is anywhere where the chassis is bonded to your fibreglass body and also anywhere where an inside panel is bonded to an outside panel. e.g. outer rim of boot, bonnet, doors etc. These will settle with heat cycling.

We did this with our first Cobra and the final body work and painting was done by a painter familiar with our brand of Cobra. He was amazed at how out of shape it was compared to other fresh bodies he had painted. That's how much settling had occurred. That Cobra is now 10 years old and it's still a pretty straight body.

Air pockets between the gelcoat and fibreglass are relatively common as well...unfortunately. The heat cycling will bring these out. You can also go around and put pressure on the body by either whacking it(in a safe manner)or role a round pole over it to crack out any air pockets.