Thanks for the info guys.
Brettski, I had thought of using that type of pipe (which is usually used for road culverts and such, isn't it?) but the idea of there being joints in the pipe made me reluctant to try it. Do the collars make it fairly watertight? The idea of using smooth core dual wall at each end seems pretty sound to me.
I will see what I can find out from the info I have so far and try to show some "before and after" if I can get the hang of posting a picture of two...
Thanks again guys!
-Dave
