If you haven't already try spinning the tube backwards (should only need 1 full revolution)until you feel the slight vibration that should travel through the pipe when the thread ends drop past each other.
Then turn to the right(assuming its the correct direction) two opposing threads should literally find each other and be effortless to get started.
Don't hate me if it doesn't work...
Edited by brwsaw (01/22/14 11:53 PM)
7'x 12'x 21' cave
3 Paradigm subs