Boil some water in a pot and hold the barrel in the water for 2-3 mintues to soften the end cap so you can remove it. Once removed, sand down the inside of the barrel and the male side of the end cap to remove any manufacturer glue residue. Use a 2 Part Marine Grade Epoxy and apply to both ends. Set the bad down barrel side down for at least a week and you should be good to go. The longer the cure time, the better. Marine Grade Epoxy is gives a stronger bond and is impact resistant. You can go with a Devcon 2 part epoxy but the Marine Grade is better