Shoe GOO . There is not a thing that it will not stick to or hold to gather. And it is waterproof. You can find it at Walmart. In the hardware dept with all the other glues. I love the stuff all ways have 2 tubes on hand
I would use 5 min epoxy to seal that up. I've used Shoo-glue but I've noticed that it shrinks a bit when it cures which I dont like. Just my 2 cents though.