Step 6: Propane Tank and Mount
It needs to be securely bolted down. The only really nice solid mounting points were already used by the generator mounting rack to hold it down to the car frame.
So, I removed two of those bolts, and replaced them with threaded rod. Threaded rod comes in 36" standard lengths. I cut one of those in half to make two 18" long pieces. That's long enough to reach from the car body to the top of the LP tank.
To cut the rod, I threaded on two 3/8ths" nuts and marked a line at the middle of the rod. I put the rod in the vise, but protected the threads by wrapping it in cardboard. I cut the rod with the cut-off blade in the angle grinder. After the cut, I unthreaded the two nuts off the CUT end of the rod. This makes sure the threads keep nice, instead of getting all mangled, and allows nuts to go back on later.
The threaded rod went up through the car body and had a washer, lock washer, and nut on the bottom. Above the floor of the car, it got a nut to prevent the rod from falling back through.
I then measured between the two rods and marked the length. Another piece of bed frame is cut to the measured length plus enough room to drill a hole in either end of the angle iron for the threaded rod to go through.
The bed frame goes through the handle and another hole in the top ring of the tank. Since it's angle, it completely clears the valve.
Adding top nuts and tightening them holds the LP tank securely in the car.