Greg and Fitz,
Your dissertation on steam bending is very interesting. In my past boat building and old boat repair I have many times had to steam new frames into boats. I have a six foot long steel pipe that I used for this, but was wondering how to steam 17 foot long pieces with a sharp bend at each end. Your pictures and info is very interesting and I think I may try this technique. In my experience the hot water does not derogatorily impact the steam bending, and in fact I have many times boiled the frames for boats instead of steaming at all. I would attach a string around one end of the frame, than wrap the entire frame in aluminum foil. I would then boil the frames in my iron pipe, three at a time, with one end sitting in an old wood stove outside my barn. I found that the frames would dry out very rapidly after removal from the pipe while I ran from the pipe up into the boat and positioned the frames for clamping. By wrapping the frames in the aluminum foil, I could pull out one frame, carry it up and into the boat, get it ready to install and then slip the aluminum foil off. The foil kept the wood wet long enough so that after it's removal I could easily clamp the frame in place . But this technique would not work well on canoe gunwales.
Thanks again for your info
John MacIver