I needed a single sided rack to haul my 17' fiberglass canoe and some light building material. My original plan was to use them in the stake pockets of my truck bed, but after trying it I realized the stake pockets aren't strong enough for that, so next I'll be making bases for them to attach to the floor of my truck bed and brackets to support them from the stake pockets.
The main tubes are 14ga 1 1/2 square. The diagonal brace is 14ga 1 1/4 square tube.
Mig welded with .035 fluxcore.