Step 3: Securing the arms
I found a scrap of pine that had some heft to it and was about the right size - small enough to fit in the backpack, and big enough that the backpack's tension straps could tighten down on it.
First, I bundled the four arms together with duct tape.
After replacing the copper, I positioned the tubes on the wood and ran back to the basement to find some washers. Obviously, a screw was going to tear right through this...
...beer...is there anything it *can't* do? The beer caps are actually perfect for this job, because they are nice and wide and the edges grab into the foam a bit.