Originally, I had a compost pile laying in the yard. I noticed that I wasn't producing enough from the kitchen to get it piled very high. It was also soaked with rain during our long rainy season. Therefore, I decided to make some compost bins to put near the house.
The first bin was a 45 gallon trash can that was cheap. This was a mistake for the top is very sharp. When working with the compost and using a shovel to mix it, I have scraped my fingers and hands on the lip. It is also kind of a flimsy bin.
To get air into the bin a 3 inch PVC pipe was used. Half inch holes were drilled in into the drain pipe. You can buy drain pipe with the holes, but I had some pipe laying around from another project. The pipe was placed vertical in the bin. Finally, a hole was drilled through the lid. This allows for air to flow deep into the bin and remove the need to turn the bin, in theory.
A couple of problems occurred, the first was that new stuff is always added on top. To finish faster I needed to mix it in; else, I would have to wait a few months after. The second problem was when removing the lid, I sometimes pulled the pipe up, if I didn't pull the lid straight up. The last problem was when it rained water got inside the bin. This seemed like a good idea because compost needs to be damp, but there was too much water that leaked in.
After a few months with the first bin, I realized that I needed a second bin. This way one bin could finish instead of having new stuff dumped into it. To make the second bin I bought a less expensive but better 32 gallon trash can. The lip is a smooth one and the can feels sturdier. I went with a 32 gallon can because it takes forever to fill a 45 gallon can. Remember, the compost is shrinking as the materials decay.
With the second bin some of the issues were corrected. A three inch PVC pipe with holes was still used, but this time it was cut short of the lid. At the top of the pipe and at the top side of the trash can, I drilled a one inch hole. A piece of one inch PVC pipe was then fed through the hole into the pipe inside. To hold the one inch pipe in place I put a three inch deck screw though it so it cannot fit though the holes. Not elegant, but it works and can be undone. Now, I don't have to worry about water getting in or moving the pipe when I remove the lid.
In retrospect, I would probably run that one inch pipe though the can and both sides of the three inch pipe. This way a T is made holding all the pipes in place. The one inch pipe would then have to have a hole drilled out for adding air inside the three inch pipe.
Both cans have holes at the bottom to allow excess water to drain out.
As I need new bins I will keep playing with my design. Though, the bin idea is probably short lived. I am working on setting up compost bins at work to get even more material. When I do, I want to start a pile again. The chicken coup will go next to the pile. This way the flies laying eggs in the compost provides a nice little diet for the chickens.