The steps mentioned below are what I took to put together a roof rack using 3/4″ pipe. This will allow me to mount two bike racks onto the Darwin.
1) I painted the pipes after washing them with black spray paint.
3) Connect the tee to the 2.5″ pipe with flange. This should thread into the connection on the tee that is perpendicular to the other two threads.
4) Thread in the 18″ pipe to two of the the tee assemblies you just built.
5) Thread in the two 8″ pipes to the remaining threaded hole on the tee.
6) Thread on the black caps to finish off the assembly.
Go back to step 4 or go to step 6 of the DIY camper plan instructions.