Neighbor gave us a solar heater last year that you set on your garage roof or the ground and run your discharge hoses to it. The only problem is it was cut before we got it and leaks. It's made of plastic or PVC and I cannot get anything to stick to it for long. I've tried PVC Cement, epoxy, that gunk for under water, nothing seems to hold. Even tried putting the stuff on cloth patches but it still keeps peeling up and leaking eventually. Any ideas for a permanent patch for it?