LePage's Metal Epoxy
Faststeel Epoxy Putty
if you have gaps to fill
LePage's Press-Tite Contact (solvent-based)
LePage's Press-Tite Green Contact Cement
3M Fastbond 30-NF
Whenever you are gluing metal it's a good idea to clean it first with steel wool or sandpaper.
(Rust never sleeps.)