I have been involved in range building, and have looked a lot of stool designs. The very best of the bunch are those that are at the Visalia, CA range. I liked them so much that I made one for myself. They are made from sections of black 12" double wall corrugated polyethylene pipe, that is smooth on the inside, and has deep corrugations on the outside. The pipe is cut to rough length with a reciprocating saw and then flattened and squared using a coarse belt on a stationary sander. Mine is an old Craftsman with a 6x48 belt and 10" disk. You want real coarse, I think that I used 50 grit. The top is made from painted plywood, circular, with a lip that extends beyond the pipe, with radiused edges, top and bottom. You can attach it different ways. I cut a plywood disk and used my disk sander to fit it so that it was a press fit inside the pipe. Then I cut some blocks from 2x4 scrap that were as long as they could be and still have the full curve down one side. I screwed and glued them so that they were on opposide sides of the plywood disk and flush with its edges, centered the disk on the bottom of the seat piece and screwed them together from the underside, then I put the assembly into the pipe, and held it in place with a couple of screws angled up into the blocks from the under side of the first corrugation. I am a big, heavy guy, and these stools handle my weight just fine. By cutting the pipe to different lengths, and adding plywood spacers, you can make them in different heights. That is what they did at the Visalia. Also, seats may be attached in different ways. I described what I did for mine. In any case, I believe that this is the most durable, lowest maintenance design that I have seen, and they are comfortable.
