FYI, it is not fiberglass. It is SMC (Sheet Molded Compound), which will require specific products. The underlying structure of the SMC may be bad and you have to take out more of it to fix the problem, or replace the panel. I had a flaking hood once and I just replaced it, as there was no quick fix (other than removing all the bad material and making sure it is sealed properly).
[This message has been edited by jaskispyder (edited 08-14-2014).]