-Don't Over Dose; Lots of glue doesn't usually mean lots of strength.
-Don't Under Dose; Little amounts of glue surely will result in the explosion of your joint.
-Use Duck Tape; Duck Tape is useful for bonding anything; that includes water rocket joints.
-Never use hot glue; hot glue will melt PET plastic and can damage rockets. If you must, use a low temperature glue gun with minimal glue.
-If you can use your stove or hot water for shrinking plastic, consider your high temperature hot glue gun. Pushing a hot glue gun on the PET plastic will tend to shrinking.
The glue that I recommend is JB Weld Clear. This stuff is awesome. It can be found at any Wal-Mart or Home Depot. Remember though; any epoxy should do the trick. I would highly recommend using sand paper on the joints before glueing. If a unrupturable bottle were at ten, and a bottle that ruptures at 10 psi were at one, I would say that without sanding your splice may be a 3.5 where as with it, and with JB Weld Clear, your splice should be able to hold more pressure that the plastic bottle can.
If you have any questions or comments, feel free to ask.
