I found after I got my tumbler that I needed more barrels! I hated having to dump the contents of a barrel out if I needed it for something else. I use the tumbler from Harbor Freight that has two small barrels on it.
Anyway, I got tired of dumping contents, washing the barrels over and over. So here's my tip of what I did to solve that problem.
I went to the thrift store and found these thermos for $1.50 each. They are very common at every thrift store I go to. Especially in the spring and summer.
These measure approx. 9" in length and 15" in diameter. I didn't measure the height of the handle.
1. Wash the thermos.
2. Cut the handle off at the swivel with wire cutters. This takes some time. The collar around the thermos will also come off after you break the handle off.
3. Duct tape the top of the tumbler on top at the spout so the spout doesn't come open. I have never had any leaks ever, just duct taping the lid. I'm sure you could glue it closed if you wanted.
4. Wrap duct tape around the thermos.
5. Roughen up the duct tape. I use a pair of scissors and drag them across the duct tape in all different directions to rough up the tape. If you don't roughen it up, it won't spin in the tumber.
6. Write the contents of the container on the cap or barrel itself.
7. You now have a dedicated barrel that fits perfectly on a two barrel tumbler!!!!!
I just store mine in the cabinet below my tumbler and never have to dump contents for another type.
This is all I use now, and rarely use the barrels that came with my tumbler. This replaces both tumbler barrels and just uses one thermos at a time.