Step 1: Get a Barrel
Step 2: Gather Materials and Tools
- the barrel
- 2 x 4 lumber: approximately 24' per barrel stand. I used scraps from a construction project
- 3/4" galvanized conduit or similar, non corroding pipe. Approximately 3' per composter
- 2 heavy duty conduit/pipe brackets to attach the conduit to the stand.
- galvanized/decking screws
- drill (an electric/corded drill works best for this job)
- 3/8" and 1" drill bits (spade bits like Speedbore are best for this job)
- saw (if you've got access to a miter saw you'll be much happier)
- phillips screwdriver
Step 3: Cut Lumber and Assemble the Stand
Measurements for this type of barrel:
- base/feet 56" (x2)
- uprights 32" (x2)
- angled supports 40" (x4)
- cross brace 32" (x1)
The cross brace is critical if you do not have a way to attach the stands to a cement pad or otherwise affix the assembly to the ground. I found it easiest to cut and assemble all the pieces at the same time, then paint them all at once. While the stands dried, I went on to the next step.
Step 4: Drill Holes in the Barrel
Experience has also taught me that 3/8" holes are a good size. Larger holes may allow for more air flow, but they also allow material to fall out and make a nice pile under the barrel. Larger holes allowed the local wildlife to sample the melon rinds and other tasty bits we put in the composter.
Spade bits are extremely efficient at this task, and the higher speed of a corded drill was helpful.
Step 5: Fit the Conduit/pipe
Make a 1" hole at the mid point of the barrel. Using line of sight, make a hole at midpoint on the opposite side of the barrel. Extreme precision is not critical here, but come reasonably close. It's more important to have the holes at the same height than perfectly opposite, otherwise the barrel will lean and slide over time.
Cut the galvanized conduit to length. The conduit should be at least 1' longer than the width of the barrel. In this case, the conduit was cut to 32". Slide the conduit through the barrel and make sure the barrel can balance while suspended by the conduit.
Step 6: Attach the Conduit to the Stands
You'll want another person to help you with the next part. First, mark the uprights to indicate where the conduit brackets will attach (in this case, 29" above the ground). Have your helper hold the barrel aloft and align the conduit and brackets with the mark on the upright. Using a short (1") galvanized or stainless tell screw, begin affixing the conduit brackets and conduit, but do not tighten at this point.
Slide and adjust the conduit until it is equidistant between the uprights (make sure there is at least 2" of space between the uprights and both sides of the barrel). Once properly aligned, finish tightening the screws and completely secure the conduit.
Add a mix of green (fresh) and brown (dried leaves, etc.) organic materials to the barrel, filling no more than half way at first. Give the tumbler a spin every few days, and begin adding more material as time goes on. We've found it necessary to have more than one tumbler, and staggered their "start" dates so we have a steady supply of fresh compost. To extract compost, simply place a tarp under the barrel, open the lid, and dump! We tried making these composters taller, so we could put our wheelbarrow under them and save this last step. Unfortunately, the lid was so high it was difficult to add more material to the barrel.
Please comment! This is an assignment in Pedagogy II at Marlboro College Graduate Center's Teaching with Technology Master's Program as part of a unit on what makes instructional technology attractive to online users.