NP. Glad I can contribute something here. All the members here are great and I have learned much by just doing a lot of reading.
One point that you may want to consider. Galvanized hvac pipe will give you less resistance than the expandable flex tube will. I used the 3.25 x 10" galvanized and...
The reason for a shaded pole motor is to completely eliminate the possibility of combustion. Any motor with a starter capacitor, no matter where the location can and will throw a spark. If the combustionable material is concentrated enough at any point around or near a non shaded pole motor...
Here ya go.
http://www.briansmodelcars.com/tutorials/tutorial.asp?TutorialID=23&CurPage=1
and
http://pages.interlog.com/~ask/scale/tips/booth.htm
and
http://video.google.com/videoplay?docid=3903621338367109945&hl=en
and
http://www.misterart.com/store/view.cfm?group_id=4617&store=001
and...