New Shower Arm will not tighten

I have just redone my shower and installed cpvc piping and the shower arm when tightened will be about 30 degrees past center of the shower, hence if turned on it will hose down the bathroom if the door is open. How do I get this to tighten at the correct location. Are there gaskets or o-rings that can be inserted to solve this? I have used teflon tape, but when the arm is centered in the shower it is just too loose to even rotate the shower head without the arm twisting in place. Help???

Try putting a couple more turns of teflon tape on the threads. It should tighten up at a different point. Adjust more or less as needed.

I will try that, but was also wondering if standard pipe dope would tighten it up at all? Or can it be used on CPVC fittings?

Use teflon tape only.
Wrap it with a little more, as jadnashua suggested, clockwise only as the threaded end of the shower arm faces you., until you can get it to stop (tightly) where you want it.
Good luck!
Mike

Thanks for the advice.