I made my own print drum from thin walled 8in. pvc irrigation pipe 40in long. For the paper channels I used 36in pvc blades from a cheap Levelor type blind and for the sealed end, a flat piece of pvc cut to fit and drilled to accept a 2in pvc elbow and on the inside surface a 5in. pvc light and splash baffle. All components were glued using pvc pipe cement. An 8in pvc pipe cap fits the open end and I attached a thick piece of pvc, heated and bent to form a handle for the cap was glued to the cap. The cap is leak proof in use with no gasket necessary. I made paper channels for 16x20, 20x24 and 24x38 in paper. I had to make a roller base for it and it clamps to the counter and all rotation is done by hand. It has worked so well that I use it for all my large prints and when I need to make prints from 50x80 in. or longer, I use troughs made of the same pvc pipe cut in half and legs glued to the troughs made from thick pvc flats or 1in pvc pipe heat bent and formed into a cradle and legs and glued to the troughs. With the troughs the biggest print I can make by my self without help is 50x96in. Because the PVC is white, it is not light proof so processing must take place under safelight. I will try to get some pictures of the tube and post them if anyone is interested. I have posted pictures of my mural troughs before so a search should locate them if you are interested. Incidentally, I can process two 16x20 prints in the drum at the same time and although 16oz. of chemistry will cover the prints, for safety sake I always use a liter just to be safe and it will still have enough capacity for two more 16x20's before exhaustion. All the above information refers to color prints. Black and white chemistry has much more capacity. When printing color prints with such large tubes, NEVER use a prewet to heat the tube as it causes staining and uneven development. If you need to heat a large drum use a hair dryer or other form of dry heat.