Quote Originally Posted by bigsby
No.
You don't have to paint the inside of your pipe. Spaceneedle was just saying that if you are worried about light. Anything shiny will reflect light, a matt black will not. The pipes and elbows he mentioned are used in the heating and ventilation of homes, and the inside is much smoother than the flexible which is ribbed. Smooth pipe gives less resistance to air than does the flexible stuff for that reason. The elbows are adjustable so they can be anywhere from 90 degrees to straight. Lowes and HD have them and are about $2 each for 6"

keylime