Right so, Oscar picked up some green clear cedar of various sizes. We cut an 2"x 8" piece into 3/8" strips approx 7' long. The bandsaw jammed up a couple of time due to the wet nature of the green wood. Thinking of getting a thinner blade for the table saw and using that instead.
A mould for the ribs 4' wide and 2'3" deep was built using bits of ply and scrap blocks of wood. We used one of Oscars old saws to mimic the curve of the ribs and scribed along it. We spaces the holding blocks 1" 1/2 apart to allow for 3 ribs and a couple of wedges to fit in.
Due to the slight dent in the pipe from our previous steaming attempt we placed 1"x 6" on top of the sawhorse to help spread the load. Plus orientated the pipe so the excess water would drip down the back and not out of the cap.
Unfortunately we had also reached the melting point of the plastic pipe. The little dent we had at the start was now has a massive depression that closed off about 40% of the pipe.