YOur biggest problem is the heat, that the glue is going to face.  I've
had several types of expoxy  fail.  Even those rated at 300Deg.
Fiberglass resin is what I found to work best.

Don Hanson wrote:

>  A few days ago I asked about repairing a leaking polyethylene water tank,
>then did some research on my own.  Well, I tried (because it was available
>locally at my sailboard shop) some  stuff called "Water-weld" that I found
>while looking for the supposed real stuff, and the WaterWeld failed
>miserably!  After painfully disassembling my camper and pouring water all
>over as I wrestled that  water tank out through the door, I  followed the
>directions then  reconnected the tank and put some water in...Worked ok
>until it was almost full, then the patch let go, dumping about 20 gallons of
>water inside...Ugg.
>  So I went back to find some "Mr. Sticky's Poly-Bonder" which is said to be
>the one product that will structurally bond Polyethylene.  I ordered some
>from the below, and while there on the website found lots of cool stuff that
>might help out some of you "project types"  I ordered at about 9am and got a
>tracking number for the shipment by noon..so they seem to be on top of it
>here.
>
>http://www.tapplastics.com/
>
>
>  Don Hanson
>
>
>