Glass body Epoxy/GRP?

[Ant]

Seeking tips on bodywork, I have a basic GRP polyester resin type Cobra, and have done some repairs and alterations!

One repair about size of a hand, was performed with epoxy resin and woven cloth on the side/turnunder of a rear mudguard etc, after it split due to muggins doing an incorrect purchase point, body lift off, and it stuck on chassis while using an endless chain, and not levering jam properly.

I have read where epoxy and polyester have different expansion rates when subjected to hot sun, and the result can be material print through, especially when using Black or dark BRG paint!

I used epoxy because I thought it would be stronger, as the repair is a secondary bond, I intend on using chopped cloth on the outside to avoid the potential print through of say woven materials, but may need to look at other fillers etc. I have looked up West Systems and Fibre Glast developments and other websites and have found nothing on this, maybe I am concerned over nothing.

IS THIS AN ISSUE WITH AN EPOXY REPAIR ON GRP BODY, AND CAN THIS POTENTIAL PROBLEM BE AVOIDED WITH CORRECT SURFACE FILLERS/UNDERCOATS/PAINT?