August 6, 2021 Update: Well, I was hoping to finish the root cellar this week, but then disaster struck: As I was back-filling the hole with dirt, I loaded it too heavily on one side before the other, and the metal structure of the root cellar shifted off its foundation (shearing the attachment screws).  I was obliged to move a lot of dirt around so I could re-excavate the side I had buried, and some of the digging had to be done manually with a shovel because I couldn't reach it with the backhoe (without getting too close to the edge of the hole for the ground to support its weight).  I eventually did get the hole re-excavated, and managed to reposition the frame on the foundation, after which I began back-filling it again, this time careful to load both sides equally.  At this point, I'm basically back to where I was a week ago on the project, after doing a lot of work to recover from the setback.

Anyway, this weekend, I think I'll upload a video I made a while back about a simple trick to make pipe taps for use on soft materials such as plastic.