Step 3: Bundle the jugs
Once you have completed four water jugs, you want to start bundling them together so that you can begin stacking them without worrying about the whole thing collapsing.
The 2 gallon jugs fortunately have two grooves that can be used to tie them together. I used some basic white string that I got at the hardware store.
I wrapped the string completely around the outside of the front groove on all of the four containers. On one end of the string I tied a loop using a figure-8 knot (although, any old knot should do). With the other end, I cut the line a little long and pulled the extra string through the loop I just made. I made sure the string was in the grooves all the way around the four containers. Then I folded the string all the way back and tied it onto the taught part of the string using a slipknot. I pulled this knot to make sure the bundle was very tight.
To begin with, I would then glue the slipknot in place using hot glue, but I later realized that this wasn't necessary.
I then repeated this process for the other groove until there were 2 taught bands wrapped around the whole bundle.