Originally Posted by corny
Well, first attempt with PVC was a failure, but not ruling out PVC as the construction material...yet.
The problem was trying to build all of it with PVC joints, bends, etc. Since the pipe only fits into fittings 3/4", the cement and bond is not strong enough to handle the stresses. Next attempt will be with solid pieces, drilled and bolted together with stainless hardware.
PVC snaps cracks and fails, expecially at the joints, which are not made to be load bearing at all. I build a $1000 frame for a tarp last winter. The wind destroyed it. The 2" pipes' fittings snapped. I ended up messing up my gel coat big time in one place and also over an extended area to a lesser degree. That experiment is over. Suggest you stay away from PVC as a construction material. There's a reason no one else in the world uses it for anything load bearing!
EDIT: I like the oak idea. Pine is not a very strong material.
Go with something that was made to take a load. Stainless steel pipe is used for radar posts, for instance. In retrospect, I wish I had used 2x4s. At least I'd have something that I could re-use next winter. For what you are talking about 4x4s might work. You could take them and carve them into something rounder or engraved/beautiful if you know anyone who can sculpt, and you could stain them any color you like.