You can make a removable lid on a plastic barrel by cutting one end off about two inches from the lid.We use plastic barrels for critter feeds... I cut a 3/4 plywood lid with cleats to keep it centered on the open barrel top..
Now you have me thinking, if I cut the top inside of the outer rim to leave a close fitting seal with the lid.. Add some anchor points to the side so the lid can be held tight with a ratchet strap, and store cool, dark, and dry why would this not work well for a barn cache ??
USED! CHEAP! 55 gallon Barrels | Metal - Plastic - Food Grade and Non-Food Grade - Bung - Open Top - Locking Lid. Located in Colorado. Feeder, rain barrelwww.repurposedmaterialsinc.com
I would love, love to find plastic barrels with the lid and metal ring type closure... Just not available around here..
OMG... Who eat that many pickles....
McDonalds, Burger King ....fill in the blank... plastic wrap convenience store deli sandwiches..
Then crimp the new top rim of the barrel like a stove pipe is crimped. Heat a small spot about 1 inch wide and two inches tall on the rim with a torch until it softens then grip it with a pair of needle nose pliers and twist a bit less than 90 degrees. While holding the pliers in place cool the plastic with a wet rag to harden it. Do that every inch around the barrel and it will reduce the diameter enough for the top to fit tightly on the barrel. If you want a better seal strech a 18 inch bike innertube over the joint.
I use the same method for metal barrels all the time. It works very well but will damage your pliers. I made a special t handle tool with a slot in it to do the crimping instead of needle nose pliers.
The same method works on tin cans, pop cans and square tins.