An attempt to build a rotating compost bin
I’m fascinated by compost. Watching kitchen scraps turn into dirt in just a few weeks time is exciting and anything I can do to improve my soil is worth the effort. I want the ComposTumbler, but finding $429 in the family budget (the price after you give them an email address) for a barrel that holds dirt is proving difficult. So, this past weekend I decided to build my own. The project was not a success in my mind but I thought I would post this how-to article anyway describing what I tried and the lessons learned in the hope that it will save others of you time and money should you embark on such a project yourself. The unit is complete and in my garden cooking up a batch of compost at this very moment, but it is difficult to use, I have concerns about how long it will last, and the door doesn’t stay closed.
Parts list
- 55 gallon water drum
- 3 treated 2x4s
- Corner braces
- Caster wheels
- Draw catches
- Super glue
- Hinges
- Screws and bolts
- Textured exterior spray paint
Construction
First, I cut a door in the side of the barrel with my Dremel tool. It worked well, but the Dremel was not strong enough for the job and I ended up burning up the motor. 
I then attached the door with small hinges and draw catches. 
Paint is obviously optional, but I thought that it would look a lot nicer in the garden if it were a natural shade instead of bright blue. 
I built the base out of treated lumber so that it would not have to be painted. It is thirty-four inches wide (the height of the barrel) and thirty inches tall. The height was specifically chosen so as to allow a standard wheel barrow to fit beneath for easy unloading. 
After I was into the project a ways, I discovered that the side walls were not going to be strong enough to retain their shape now that I had cut a large hole in it. I stabilized the side walls surrounding the door and the door itself with wood strips. It helped, but it still flexes too much to shut tightly. 
Here is the finished product in the garden. 
The base turned out well. It is solid and should last quite a while. The major problem is the drum. The side walls of the plastic drum are simply not strong enough to retain their shape as the drum rests on the wheels with all of the dirt inside, with a door cut in it, and as the plastic softens as the temperature changes. Perhaps I used the wrong kind of paint, but the paint is also not sticking to the plastic well and has already started flaking off. If I had been able to use a metal drum instead, I probably would have been able to produce something that I could have been happy with. The only place I have been able to find one is through an online distributor though for 75 for parts and another $40 for paint.