Don't use fiberglass, it will crack as well! My steel hood has cracks in every corner of the fiberglass scoop where it was attached to the hood using fiberglass resin.
Ding-Ding-Ding!!
Fiberglass resin does not stick to any metal surface! It only has a physical adhesion i.e. scratches from sanding/grinding. . I use SEM panel bond. Use it and never worry about it again!
