I wanted to build a strong and versatile tank rack that can be used in my boat and truck. I used a ½ thick schedule 80 PVC pipe that was 7 ID. I cut the pipe into 3 bands and then removed 30% of the ring. I then tooled the edges smooth and mounted it to a ½ plywood surface laminated with an aluminum face. I used treated 2x4 blocking on the back side of the plywood and screwed the C brackets to the board and lumber using #14 x 2 SS screws. The screws are recessed into the PVC and will not come in contact with the tank. The rack can be mounted vertical or horizontal and now can be used where ever I transport my tanks. The PVC pipe will open enough to allow the tank to snap in securely. I can actually hold the mounting plate upside down with the tanks in place and they will stay put. I have extra PVC rings cut for future rack projects or will sell them to some who wants to build a rack like mine.