When I worked in the body shop at a Chevy dealership in the late 1970's, GM made a structural cement to bond metal hood braces to the fiberglass hoods on the Brigadier and Bison trucks.This stuff would bond anything. Knowing how well some of the glue's hold, I personally would still weld a metal panel together on a rust repair. That's the way we always did it. Oh No, I sound just like my father did when I was a kid.(ha)