Compost Tumbler





Introduction: Compost Tumbler

I'd been looking at these fancy schmancy compost tumblers online as I'd gotten tired of turning my compost pile. There were 2 big detractions from these prepackaged tumblers; 1- too expensive for my penny pinching ways, and 2- they all sat way up in the air making it quite difficult to rake and shovel material in and out.

This looks to solve those two issues.

Step 1: Materials

1 55 Gallon Barrel (preferably one whose previous inhabitant was not poisonous)
1 3 Ft. x 18 In. Board
4 Bricks
4 NON Pivoting Wheels
2 Pivot Hinges
2 3 In. Pin Locks


Cutting Implement (I used a miter saw)

Step 2: Basic Assembly

Cut a rectangular hole in the side of the barrel (this is easier said than done). I cut mine to be 18 in. x 20 in.

I didn't want the hole to be too big as it would have to carry considerable weight when rolling the full bin around, however, I wanted it to be big enough to get a rake or shovel into.

Attach the top edge of the door with 2 hinges, and then use the pin locks on the bottom edge. Make sure to place the locks on the side (parallel to the ground). I mistakenly placed them vertically along the bottom and when the barrel flexed, the door popped open every time.

Step 3: The Platform

The trick of this is to place the four wheels on the board so they keep the barrel rolling. Too far apart and the barrel bottoms out, too narrow and the barrel pops out.

Screw the 4 wheels about 2-4 inches in from the top and bottom. this lets the groove of the barrel keep it on the wheels.

Don't place the wheels too close to the middle, you don't want them hitting the door or door hardware (ask me how I know!).

Step 4: Aeration

Drill 1/2 inch holes around the barrel. I chose not to drill these in the door- no reason. These holes allow for proper aeration and drainage should your compost get too moist.

Step 5: Final Assembly

Place the wood plank on bricks to keep it off the ground. Add the barrel. Spin it a couple of times and load it full of rotting jack-o-lanterns to get your compost off to a good start!

Some parting thoughts:

1- I might consider getting bigger hinges and locks- I've not filled it completely yet and am a bit concerned about the structural integrity.

2- If you're a perfectionist, replace all the screws with short bolts and nuts- they're likely to stay assembled longer and you don't have to worry about getting cut on a pointy screw.

3- For those of you needing a primer on compost- leaves, yard clippings, kitchen scraps (meat/fat/oil are NO NOs, veggies, eggshells and breadstuffs are YES, YESs), maybe some worms, and water til moist sponge consistency. Turn once or twice a week.



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85 Discussions

I built basically the same composter 4 years ago. Over the years I made a few improvements in the original design. 1. Used 4" non-swiveling casters, as the little ones did not support the barrel enough, and it sagged when full.. Originally used cheapy 1.5" and they quickly proved inadequate. Turning the barrel is easier with the 4" when fully loaded as well. 2. Used pressure treated 4x4s as a base to raise the whole thing 3 feet off the ground to make loading and unloading easier. Mine sits outside year round and this helps a lot. 3. To eliminate any further sagging, used 1.5" (4) furring strips lengthwise strapped onto barrel with (2) 1" ratcheting tie-down straps. 4. Cut holes in each end and inserted 3" PVC pipe with many 1/8" holes drilled in it for air circulation, with a small blower mounted to one end to force air into the compost. The other end is capped. It has produced about 1/2 a barrel of fine compost 6-8 times a year, using shredded dry leaves, kitchen waste and grass clippings, loaded completely full. Total composting time with the blower is about 6 weeks, without it about 10-12 weeks. The door on mine is larger as well, using 4 hinges instead of 2. My next modification, this winter, will be to add a small gearmotor with a rubber tire from a old wheel barrow mounted to it's output shaft to continuously rotate the barrel during a batch. I am hoping it will speed up the process further.

1 reply

I know this is 7 years ago, but how's that going?! Could you post a photo or two?

Hi, JP here from South Africa! I just made this and it works like a charm! Thank you for this!

One of the problems I have had with mine is rusting hinges. Pretty much anything that gets exposed to the compost will rust quickly. I replaced my metal hinges with 3/8" zip ties. Use several of them along the length to minimize warpage. So far it seems to work fine. I also cut 4" sections of all thread and bolted them through the walls to assist in stirring. They work great!

Just made myself one today I use a moving dolly as the base, small door in mine to keep the integrity of the barrel, I found a place in my town that recycles barrels from big companies they are food grade (mine comes from a pop maker) so is easy to clean instead of the ones with soaps or other chemicals will post pictures once I finish the holes for ventilation. Thanks for the idea

this also helps to do compost cleanly, the only time I did it, had a problem with mice cause of the remaning food I used

About how powerful do you think the gear motor should be in order to be able to rotate a heavy drum slowly (safely) but strongly?

I am building this compost bin today using 2 skate boards mounted on a plastic pallet. I AM EXCITED. So far so good. Thanks for all the great additional ideas (for me, needed). Got the barrel from a craigslist ad ($10) and the skateboards were free from a trash can after a yard sale. I am sure my neighbors will appreciate looking at this rather than the ugly black round hard plastic one. I am going to put a flexible plastic pipe wedged from opposite "sides" for a stirrer.
THANKS again.

I see it's been almost five years since you've posted this instructable. I'm wondering if you've had any problems with the wheels rusting and siezing up on you? Great job by the way.

You can go to a car wash and pick up the barrels for "free". But best to call first. I picked up 6 barrels last year for free.

8 replies

My barrels came from a car wash and had sodium hydroxide in them. How do you neutralize sodium hydroxide and ensure that it doesn't contaminate your compost and ultimately kill the plants your using the compost on?

Empty out as much as you can. Wash it out with plenty of water (wear gloves and goggles and long sleeves) let it go down the drain. Sodium hydroxide is basically a drain cleaner and it is easily soluble in water. Be careful not to get splashed. The water may heat up a bit.

Use an acid. While I'd suggest HCl (Hydrochloric Acid), it's not really at your local CVS. Acetic acid could work if enough of it is used, that is, vinegar. Acid + Base (NaOH) will result in a relatively harmless salt and water, depending on your conjugate/neutralizing agent.

If you poured it in and then coated the sides with it to neutralize the NaOH, I think that should be plenty. While I can't seem to balance the Chem eqn, this is what I suspect:

C2H4O2+NaOH -> Na2CO3 + H2O.

Na2CO3 is sodium carbonate which is an irritant: Otherwise, it should be OK. Just wash everything out with water afterward.

Oh yes. I had blancing the alittle trouble balancing the equation myself? LOL! Thank You for the info. I gave it a good vinegar bath and a water rinse.

vinegar (=diluted acetic acid) neutralisation has this equation:

CH3CO2H + NaOH --> CH3CO2-Na + H2O

wash your drum with water a couple of times, then a couple of times with vinegar.

NaOH is corrosive but will get neutralized by your compost eventually, so i is not going to kill your plants, unless you have a lot of it. You can get a cheap pH testing kit from any garden center if you want to check.

best Thomas

I know you have already found a solution to your problem but I have a suggestion. I own a pressure washing company and use sodium hydroxide to restore wood. I use vinegar to neutralize the product and then I wash it with a car wash solution. It has worked for me. I am not sure if that is enough acid to neutralize for the purpose of compost. I would suggest lime in the compost mixture but again I am learning how to compost for my yard so I may be wayyy off the mark. I hope this helps.


I love the design of this. I just built mine last week. I filled it up about half way and found that the compost did not turn but simply slid down the interior of the plastic barrel. (perhaps this is because I have an abundance of pine needles in my compost?) To fix this I drilled some holes and screwed a few bolts in so that they stick up inside the barrel about a half inch. (I feared that using screws might result in a nasty gash in my hand while trying to scoop out the compost.) This gave the compost something to "catch" on while turning and now the compost flips over nicely.

How have the wheels held up? my concern is the weight of the barrel on such a small surface? When the barrel gets heavy will it still roll? I am checking these out to make one of my own and I am trying to avoid mistakes in the construction process. I must say your design is one of the simplest :0)