Originally Posted by tire
i'd just worry about bung stripping or tank cracking over time.
I'm not worried about the tank cracking as it will be a minimum of three layers of fiberglass mat/epoxy lamination with several layers more than that everywhere pieces overlap, and that's in all the corners and along all the edges. My plan is to drill holes around the flanges of the bungs to serve as keys to resist turning. That should hold them.