Agreed. As one who worked with composites (carbon fiber, glass, kevlar, etc.) for almost 30 years I can tell you fiberglass is not made to patch metal. Have I seen it done? Yep, lots of times but I've never done it personally because it's not the right way to do it. Rust is like a cancer, if you don't cut it ALL out & treat what's left it will come back. Eventually his "repair" will fail.
