Cut the shelves to size using a table saw. See the notes for cut lengths.
Using your 1 1/8" spade bit, you're going to drill three holes through each 70" board and two holes through each 36" board. Your holes need to be in the same place on every 70" board and the same place on every 36" board since you are stacking them.
Sand all surfaces until smooth.
Apply Ebony stain and allow it to dry. Lightly add Carbon Gray in random areas for a weathered, reclaimed appearance.
Once the stain is dry, apply two or three coats of water-based polyurethane. Allow the finish to cure completely.
Clean every pipe fitting with a degreaser or mineral spirits to remove the factory oil coating.
Assemble the pipe sections by connecting the pipe, tee fittings, elbows, and flanges before stacking the shelves.
Beginning at the bottom, slide each shelf onto the pipe assembly and continue stacking until the unit is complete.
Level the shelving and secure the top flanges to the wall using appropriate screws. Whenever possible, mount directly into a stud for maximum strength.