phasing time limit

[Phanto]

I have not had any success whatsoever and am still trying the whole AP thing.  I just started reading about the phasing thing and was wondering if there are time limits associated with phasing.  In several books I've read people say that they have only been able to be 'out of body' for  only so long depending on their skill level.  I'm wondering, Frank, if you are limited in any amount of time that you are able to phase.