Here's a link to an earlier version of the rig that I made bending PVC pipe. I used a hot air gun and slowly bent it around an 18 1/2 in garbage can lid. Hope it helps.
http://www.dvxuser.com/V6/showthread.php?t=54867&highlight=figrig
http://www.dvxuser.com/V6/showthread.php?t=54867&highlight=figrig