Today’s waste- to- resource project is a tumbling barrel composter that we’re going to make out of one of those cool Greek olive barrels we used to make a rain barrel back in the summer.

Is anybody out there old enough to remember Captain Kangaroo on TV? He was always showing you how to make cool stuff out of a shoebox and a pair of scissors. At least it was cool to kindergartners. Once I got to high school, not so much.

Anyway, today’s waste- to- resource project is a tumbling barrel composter that we’re going to make out of one of those cool Greek olive barrels we used to make a rain barrel back in the summer. We’re also going to be reusing some scrap wood we found laying around the house to provide the barrel support.


First, we’re going to lay out our materials. Besides the olive barrel which I got from a local recycler, I found some pressure treated 2x6 lumber salvaged from an aging deck, a couple of scraps of black locust- the wonder wood we featured on Greenopolis recently- and two pieces of red oak left over from  the maple sugar shack that I put a steel roof on recently.

I went to the hardware store and bought (2) ½ inch carriage bolts 8” long, and six nuts and washers to go with them. While I was there I picked up a ½ inch augur bit and spade bit for my cordless rechargeable variable speed drill. It is an article of faith with me that you can never have too many tools. In additional to the drill, I needed a tape measure, small square and a circular saw ( now’s the chance to pick one up for yourself- tell your spouse or friend you’re making them an environmentally friendly gift!).


Here’s the carriage bolts and drill bits- you’ll see where they go in a minute.


This pile of miscellaneous pieces of scrap wood will form the base of our composter. You could make it out of steel or PVC pipe- try to reuse stuff that otherwise would end up in the trash or landfill. Make sure you pull out the old nails and screws. Don’t buy new- it’s just a composter for gosh sakes! As my Dad would say, “We’re not building a cathedral”.


Start by drilling a ½ inch hole halfway between the top and bottom of your barrel- Our barrel is roughly 36” tall, so we are making our hole 18” from the bottom of the barrel. It doesn’t have to be perfectly centered, but good enough so you can rotate the barrel around easily later.


Now, using a string and your measuring tape- measure the circumference of the barrel at the level of the hole you just drilled. Divide by 2 and you should be on the opposite side of the barrel. Drill a second hole here directly across from the first hole. You should be able to see straight through the barrel. This alignment is important to make sure the barrel pivots around the same line.


Next, grab your drill and spade bit and drill two more rows of holes all around the barrel above and below your first two- this is for ventilation for your compost. I spaced them about 6” apart.

Now set the barrel aside for the time being. We’re going to make that pile of scrap wood into the base for the composter. Since our hole is 18” above the bottom of the barrel, and we want the barrel to be able to pivot freely, we are going to make our upright post about 24” tall. There will be two of these, one on each side of the barrel, and the carriage bolts will run through the top[s and connect the barrel to the post. I used 4x6 oak simply because I had some. You could use 4x4 material or even a 2x6 or 2x4 would work. But I like to overbuild when I can, so the oak will do the job well. 


Once I’ve cut the posts to length, I mark a spot centered 3” from the top.


Then I take that nifty new augur bit I bought and drill a hole clean through the post, keeping it level and plumb. I want the hole to be as close to horizontal as possible.


For the rest of the base, I laid a piece of locust down and cut two diagonal pieces of pressure treated to support the post and connect it to the base. Should look roughly like the above. Notice I drilled the holes the long way through the oak- this will give me roughly 2 inches of bolt extending out the other side to hang the barrel on when I’m when I’m finished.


Then screw it all together using 2 ½ inch coated deck screws……..


This is “Drill, baby, drill!” I can support…….


Slide the carriage bolt through the hole, tap it into place……….


….and tighten it up with a washer and nut on the other side. The extra bolt sticking out is where you’ll hang the barrel. Now build the base for the other side the same way you did this one- make sure the holes in the posts align with each other, because you want the barrel to swing around a straight line.


Now you are going to push the barrel onto the protruding parts of the bolts on each post…..


…slip a washer over the bolt on both sides of the barrel, and a nut on the inside……..

and tighten inside and out….

…then add a second nut inside to lock the first nut in place. Repeat this on the other side.

Make sure the two sides of the base are evenly spaced and that the barrel swings easily between them. Secure the two sides of the base to each other with some 2x2 scraps- in this case, one piece of pressure treated and one piece of lack locust. It’s what I had around.

Step back and admire your work, making sure the barrel swings between the posts…


It should look something like this when you are finished……

And swing easily like this, to turn the compost and mix it. You can stain or paint the wood or just let it weather into a nice gray. The oak, locust and pressure treated will last a long time, maybe until you become compost yourself.

You’ve just reused a perfectly good barrel, saved some pressure treated lumber from the landfill, and put some other scrap wood to good use. Now you can unscrew the lid, throw in some food scraps and leaf mulch, and start composting it. Turn the barrel from time to time to mix the stuff, and when it’s broken down enough, open the lid and shovel it onto your garden. Waste-to-resources to make the composter that keeps turning waste-to-resources for a long, long time. Now let’s go get a beer and build a Buddhist Temple or two!

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