I have read different ways to join ABS to PVC and decided to conduct my own experiment. With14 joints and using purple primer on both fitting and pipe, and installing a 10ft. water head, the following glues were used: Oatey's ABS to PVC "green" Weld-On's 704 and 735 Wet 'N Fast PVC glue ACE's ABS Flow Guard's CPVC (believe it or not) No leaks, but a Fernco coupling may be the best for piece of mind.