Glue, and i used 4" pan heads to toe screw each joint also. Read the thread. I know what im doing.
The first time I bought the rod I paid 3$ a foot, and bought two 4' lengths at my local Rona
This time, I paid .30$ per foot, and bought two 5" lengths from work.
It seems you do know what you're doing, I was just checking. I missed the screw holes at first. The glue should be more than strong enough.