Gardening and composting are two homestead concepts that go hand in hand. I could have gone out and bought a compost tumbler but I thought I would rather build one myself.After looking at a number of compost bin designs online I decided to build something very similar to the instructions found here and expanded on here. I updated this post in September after using the compost tumblers for two months.
The first thing I had to get a hold of for my compost tumblers were two 60 gallon barrels. I had gotten barrels from Stuart at Perennial Harvest in the past so I called him up and lined up 2 black food grade barrels. I took a trip to the local hardware store to get some of the other supplies I did not have on hand – some 3/4″ galvanized pipe and large diameter PVC pipe.
Building the Compost Tumblers
Building the frame for the compost tumblers was a simple enough process. I used a miter saw to cut the 2″ x 6″ lumber to the correct lengths and a jigsaw for rounding the tops. My center design was slightly different then either of the plans mentioned earlier. I felt it would be simpler and stronger to basically make two of the single tumblers and have them share a leg support.
Once the frame was built I drilled holes in the barrels and mounted the ventilation system. I also drilled air holes in the handles of the compost tumblers. Next I used some window screen to finish them off. Where the other designs had used glue for this I instead used zip ties. Finally I drilled the holes for the axle using the barrel seems to line everything up.
Mounting the barrels on the axle and frame is probably the most challenging part. The holes I had drilled were so tight I had to file them out a bit to get everything on.
Update September 2014
The compost tumblers have been working well. I have been focusing on filling one side until it is loosely packed and then giving it some time to settle/decompose. The material decomposes quite rapidly and it seems like they are producing compost reasonably well. There is a noticeable heat when opening the tumblers and a pleasant smell. The tumblers are not as heavy as I thought they would be and the spin easily enough.