I used a product called Lord Fusor bonding agent,For Metal. I just checked there web site and they have a product that can be used for bonding metal to fiberglass,It's called SMC Repair Adhesive. I used there bonding adhesive to bond My rocker panels on and patch panels on My fenders. It's really good stuff.Go to a good body shop or a good auto parts store to find it.You wont find it at auto chain stores like autozone or vip.