I recommend using epoxy putty(not glue), you should really prep any surface for proper hold. Mending metal to plastic using glue rarely provides longevity since plastic bends and also responds differently to temperature changes in the realm of expansion/contraction. Light scuffing or even using a hard abrasive won't be enough if you want it to last, even when using glue or putty since many of us are in the habit of removing or constantly replacing the atty.
Best results are to drill small holes or deep, deep gouges. For best results using epoxy with the connector. Drill small holes (usually 2-3) around the base of the connector with a drill bit. I use a #60 drill bit by Irwin. After that's done, press the putty into it until it seeps through and pack behind and in it as well. It should now go no where.
Now, we're going for longevity. So, why not remove the silicone O-ring in the connector?
What I do, is remove it. Solder the positive and negative wires in their proper place.
With the positive portion removed from the connector. I pack the center of the connector(or negative housing) with loctite 5 minute putty. Now I fish the positive wire through the front of the connector until the positive brass portion is flush with the housing. Quickly clean the surface with a damp cloth and screw an atty on so it's a molded fit. Pull out my trusty multi-meter to test for shorts. If all is well, let it cure.
It's 5 minute putty, so obviously this must be done quickly.
