An alternative to JB Weld would be a high quality epoxy mixed with milled fiberglass. You can purchase bulk milled fiberglass, or you can simply take a piece of lightweight fiberglass cloth and cut your own short shavings which can be mixed with the epoxy. Combined it ends up being a white creamy color.
However, a potential long term problem with any adhesive, is getting the area clean enough to create a proper bond. And unless it's a porous material, which the adhesive can penetrate, it's about impossible to get a permanent bond.
