Hi Joel, you either need to change the materiel to be 2 sided or shell the inside of the pipe. It's probably just better to set the material to be 2 sided though. Keep up the good work :)
Yes, the best way to go about it is to create both sets in whichever app you're using before importing into the editor. I'm not sure which software package you're using, but it's very easy to do in Max: just slap a second 'Unwrap UVW' modifier on top of the object, and then set its Map channel to 2 (as opposed to the…