Lowes sells the tubes to cover fluorescent lights with. They are around 3 dollars. They do have end caps, but the end caps have small holes in them to allow the bulb terminals to stick through, so they need a little work. I think two rods in one tube might be a bit tight, but if you put the handles at opposite ends it may work.
EDIT: I just saw you said three inch diameter, the bulb tubes are nowhere near that big around. Two rods still may fit in them depending on the rods though.
Edited by james__12345 (05/30/11 06:54 PM)