In the past I have just simply used a pair of vice grips to flair out the end of the pipe slightly, all the way around the circumference of the pipe. It doesn't take very long to do, and it has worked well for me. Been running 16psi for a long time now and never popped a coupler.

Just make sure you don't flare it out too much that you will encounter difficulty when slipping the couplers back on.

By the way, I like the JB Weld bead idea proposed above. Never did it myself, but I cant see why it wouldn't work.