[racer1442]

I had this same issue a few years ago with mine and tried nearly everything from panel bond, seam sealer to windshield urethane. What worked and never had an issue again was silicone for gutters/ eavestrough. I'm in Canada and used Mono Silicone Pro, it's a grey metallic colour, flexible, water and shrink resistant.

I grounded everything out that was there including what was left of the original. I used some abrasive sand paper like 80 grit to the seam and whatever would overlap on each half. Solvent washed throughly, taped each half to run a nice bead. I had someone hold and spin the wheel and I used a plastic trim tool to really force the silicone into the seam. I ran another bead and had it spun again and just smoothed with my finger to have a nice overlap on the halves. I let it sit for a couple days before mounting but it's been perfect ever since.