I am looking to build a mixing station and the two barrels I have are sealed plastic food grade with small bung holes on the top. I was hoping to not need to cut the tops off but am struggling on how to install bulkheads. Has anyone just used piping through the top openings or is there a way to add bulkheads to the bottom 1/3 of the barrels without needing to reach all the way down to hold the backside of the bulkhead to tighten?