Hi All,
The sailtube was made from 14" diameter, smooth-wall duct from a local A/C contractor. The endcaps were also obtained there. Banding to secure the tube is common 1/2" strap banding used in many warehouses. Steel rivets secure all the hardware. I used portions of a 6" hose clamp (for dryer duct) to fasten the banding to the clamps. (I now recommend using a heavier gauge clamp just for piece of mind - the metal in the current clamps is "soft"). The brackets I had bent-up in our sheet steel press at work. I allowed about 2" clearance for the tube diameter and used a metal-blade scroll saw to make the relief cut. I also used edge dressing from a local electrical supply shop so the bracket edge would not chew into the tube. Brackets are fastened to the trailer with (2) 1/4" diameter bolts each. I mounted the hatch hinge off-horizontal so the hatch would hang out of the way when I'm moving items in and out. The 14" diameter allows me to store the mainsail, jib, paddle, rudders w/tillers, tiller cross-bar, extra life jackets and other collateral gear. The hatch is self-draining by fit. There is plenty of clearance between the tube and the boat. The whole assembly is rigid during travel and should prove durable over time. I expect some oxidation but for me that's OK. You might want to cover the rivet tips inside with some type of plastic/rubber cap at the hinge and lock bracket to avoid marring any items inside whilst moving them in and out. This is a fairly general description, for details please contact me at skipper08022000 at yahoo dot com. In the message to follow I'll discuss the re-paint portion of the project.

Cheers,
Eric