I wondered who was taking all my building materials off my job sites. I have made the sail tube out of pvc but it is real heavy and cost a lot around 100.00 for 12' ( getting it from a construction site is steeling unless you ask first). I have had a sheet metal shop make about 16 boxes at a good price out of galvanized sheet metal 10'x 22"x14". The first one's I made about 6 years ago were 125.00 each and have lasted great. The newer one's were around 250.00 each. I have added a 4" piece of pvc to one end to hold the spin pole. The drops from the pvc pipe do make great hull cradles. I put mine on the grill on a piece of foil at 250 deg and then shaped them with a piece of wood cut to the shape I wanted.