Indeed, Jack. My father commented that the iris would act like a chimney flu baffle on a wood stove. Could be a neat feature for sure!
I would love to discuss any collaborative ideas you have, too. Sadly, I live in an area that is essentially devoid of creative craftsmanship. I have to resort to chatting on the interwebs to find people like you to work with. Shoot me any ideas you have, I would be happy to work on them when I have some free time.
I got the pipe project prototype finished today, I threw up a new thread with lots of new pics here:
http://www.talkshopbot.com/forum/sho...d=1#post132874