This little tool is the slickest solution you can imagine for the trial of trying to set posts or horizontal bars while working alone.
The Johnson Post Level is made of hard plastic. It is simply two “slabs” at right angles to each other with three small bubble levels mounted along its three planes. There is a rubber band attached to one side which you slip around your post and hook to the tool on the other side. If you are using posts with square corners you are all set. If you are using round posts that are symmetrical you are all set.
You just dig your hole, slip this on the post, set the post and hold it with one hand while returning the dirt to the hole by shoveling with the other hand. For upright posts, use the two horizontal bubbles and make sure they are both centered. You can tamp and adjust as you go. Of course, it’s even easier with two people, but I usually find myself doing these jobs alone.
For horizontal bars, use the bubble that is mounted along the angle of the tool, just as you would any bubble level. But the fact that it’s fastened to your bar saves all the headaches of trying to hold it in place while working.
Each side of the tool is 3.5 x 5.5 inches, so it’s ideal for 4 x 4 posts, but you could make it work on other sizes. The sides are cut in where the band fastens, so you can easily use it on posts as small as 2 x 2 inches. For bigger posts you might need to loop an additional rubber band on to reach around it. Not a big problem in my book. I just love simple solutions to major hassles!
The only negative I can see with this is that if you are using rounded posts that are rough and uneven, you would need to decide where to place the tool to approximate the plane of the post, but you would need to do that in any case. That problem has nothing to do with this tool.
I found this at a hardware store a few years ago for $5.99, but they are available on line from the Johnson Level & Tool Company for $6.34.