Best glue for flexible PVC?

[Summit]

I need to seal the seams between two pieces of heavy duty flexible PVC to make this bag waterproof again. What is the best glue I could use for this (that I can get at the hardware store or walmart, not something mailorder)?

[Conundrum]

I use aquaseal on kayak gear. It's flexible and handles cold temps better than other things I've tried. I couldn't say how it would stick to pvc though. Maybe a thought.

[PNWbrit]

I need to seal the seams between two pieces of heavy duty flexible PVC to make this bag waterproof again

http://completegadgetshop.com/shopimages/products/normal/sheep.jpg

Water? ;)