Here is an easy way to make inexpensive, light, durable fuselage tubes from Dollar Tree (Readi-Board) foamboard, Depron, or any light light foamboard where the paper can be easily removed.

This is an updated version of this technique with some variations you can consider for your builds, including embossing (depressing) the inside corners instead of removing the paper from the foamboard, and some additional adhesive choices.

The tubes are typically used for fuselage construction but can be used for motor nacelles, power pods, FPV "backpacks", pontoons, biplane wing joiners, couplers, etc.

Construction requires foamboard, packing tape (aka: carton/box/shipping tape), and an adhesive to join the tube. White Gorilla Glue and 3M 77 spray adhesive are favorites, though hot glue or CA will work.

Depron users: Please see WayneRC on YouTube    / wbw40  
He is a pioneer in using Depron for this building technique.