Hi Carl, I know what you mean about vermiculite. So hard to keep smooth. The worst part is, when you go to replace a liner it is almost impossible smooth out.

As for the duct tape, I use it on every pool I install. Have for over thirty years, never a proplem. I take pools down and move them from yard to yard on a regular basis, never a problem from duct tape.

Maybe it's a guy thing but I sear by it, Dennis