While looking in my tubing rack for some tubing to use for the pair of vertical supports I spotted the perfect thing. I was going to need to make threaded end plugs for whatever tubing I chose to use. But there in the rack was a pair of tubes that already had aluminum end plugs with threaded centers in both ends. I needed 43" length and these were 46 1/2" so I could cut them down 3 1/2" and reinstall the plugs.
This pair of tubes, with end plugs, had been sitting in my tubing supply for 46 years and now they were perfect for my glider support project. These were titanium tubes, 3/4" dia x .022" wall - ridged as a 2 x 4! I also used more of this tubing for the trailing edges in the Skysail. These two pieces had become surplus from one of the changes I made in my Skysail hang glider back in 1972.
Funny; tubing from my first hang glider being used, after 46 years, to support what is probably my last hang glider.

Frank Colver