Yep, its too big, but cutting it would be easy, 10 bucks for a angle grinder at Harbor freight, and you can use the conduit sleeves at lowes, or use smaller pipes inside. No way you are welding that together...that stuff is crazy thin (unless you are an awesome welder, or know someone who is)

Actually, I would use broom stick/dowel rod for the inside and just screw the tubing to it...