twin compost bin

this is a year-round, easily-dismantlable and movable composting bin. It has two compartments: one for matured compost, and one for fresh vegetable waste. you can let your compost mature for one year while you fill the other compartment; come spring, you then use the ripe compost in the planting of your garden (ymmv depending on your climate/seasons and quantity of composting matter).

Step 1 Materials needed

you need some wood and some basic tools.

the wood we used was cheap, unfinished 1"x8" (nominally 1" thick by 8" wide, but actually 0.75" by 7.25") spruce typically used for decking, under finished siding or sub-flooring; for a longer-lasting - but considerably more expensive - bin, consider using cedar or pressure-treated wood (do *not* use pressure-treated wood that's older than a couple of years, as it may contain arsenic; the stuff you find in stores now does not contain arsenic and is deemed safe for projects like this).
corner posts were 4' long 2"x2"s, pressure-treated (nominally 2" , but actually about 1.5"); they probably don't need to be quite this long, but this will depend on how deep you want your bin to be and how soft your ground is.

for tools, you will need:
measuring tape and pencil;
speed square;
saw (either hand saw, jig saw or table saw);
hammer and chisel (or flat blade screwdriver);
optional coffee can or similar to slip over corner posts when hammering into ground to prevent damage to top of post.

Comments

[simonborganic]

Thanks for taking the trouble to record all these photos and instructions - very inspiring. I tend to turn my compost more than you, and it seems to accelerate the composting process. And I tend to use my compost before it has completely composted down - this is to feed the soil with all stages of decomposition. I am however thinking of making a sieve so I can take out the fine compost and leave the larger pieces for the next batch. As a suggestion, when you empty one bin, turn the other bin over into the empty one. this allows you to thoroughly mix the inside with the outside and top with bottom so it starts to work again. I would use a fork for this instead of a spade - lighter and easier to pick up a load to sprinkle it over the new pile and less likely to chop up the worms - the guys that do all the work. By the way; I've tried all sorts of bins including tumblers and I'm going back to the basic style of bin that you have described so well here. so save yourself the trouble of experimenting - stick with this one - they do a very good job. And yes a lid helps - a sack or carpet is excellent - the worms like to be protected from the sunlight.

[camp6ell]

thanks for your constructive comments. i think most years we have turned over the full bin into the empty bin; this year, for no good reason, we didn't. does chopping worms in half not give you twice as many worms? :-) i'm kind of half serious here, right? this year, what really struck me was that there's no bad way to compost - whatever you do, however little you do, it still works - pretty pleased with our formula now, which involves very little work.

[rapidprototyping]

leaf mold makes the best compost then comes pine duff nationwide think of the tons of leaves landfilled this is wrong as thats our replacent nutrients we are depleating soils by throwing out these valuable resources. composting takes place in the rivers and creeks through leaf destruction on its way to the ocean this helps filter and clean our water. while vegitable composting contributes to the compost diversity it may possibly add some residual pestacides or herbacides minute amounts but still adding things at molicular level should be of concern. Our water may contain thousand of bad substances the water treatment plant can not extract coming or going. I use wire and form a hoop of wire fencing material easy to relocate and in different sizes. Alarge yard cart help get thing from yard to bins and turning is recomended but i don't turm mine at all just sheet mulch it on the gound but not around the base of the same trees that shed the leafs just incase it has problems things break down over time black gold it's called

[AmyLuthien]

Handy!  But I'd point out that you probably don't want to use pressure treated lumber for your compost bin if you're going to spread the resulting compost on any vegetables/herbs you intend to eat.  Pressure treated lumber is impregnated with chromium, copper sulfate and arsenic and highly toxic . . .

[camp6ell]

(removed by author or community request)

[AmyLuthien]

True, unless you used a piece you've had lying around for a few years . . . ;)

Cedar is the definitely the way to go though, or redwood.

[camp6ell]

(removed by author or community request)

[AmyLuthien]

Yes, they did stop using arsenic in 2003 for residential use.  Arsenic is however still used today for commercial applications.  Wood intended for residential applications typically is treated with amine copper quat  and copper azone.  Whether or not those are safe in the long run really hasn't been determined.  Personally, I would not take the chance. 

[CostaTim]

Hi! I had the old pallets. He made a box of them. Obil PVC. I think that would be better if the new facilities will fall down. When filling the box, the board vytaskivayutsya. And fresh waste come in contact with the worms and microbes old compost.

[gingertech]

nice idea never really thought of the dual bin idea, i have a plastic store bought composter alas this would have been much cheaper lol, quick ideal; perhaps a lid to keep the heat in and stop things growing in it?

[gannonbill]

could you add some old windows that you just sit on top, that would keep heat in and the sunlight would still be able to get into it

[camp6ell]

yeah, a lid would probably help speed things up. it's working out ok just now without it though - probably takes 6-9 months to decompose, which is totally fine as we only need a year for it to happen (when we will next use compost in garden). funny you say to stop things growing in it... we got a great big squash plant growing out of it this year from compost seeds, so just left it and have had quite a few delicata squash.

[gingertech]

lol how odd:)

[6monkeyRS]

How long does the leave or material take to decompose? I have tried this for a year, but it took a long time. We have several tree around my house, and get a lot of leave in Fall-Winter, and would like to make something like this, for Spring Garden. This is a good idea, I can build this around the area that I want to set my garden. Then just move it around from year to year.

[camp6ell]

for us, in the north east of the us, we give it a year. we could probably get away with less as long as everything was chopped up pretty small before it went in there (and conversely, corn cobs or whole loaves of bread might take more than a year if left unattended). basically, we empty one side and use it in the garden in the late spring when we are planting, and then start to fill the empty side, leaving the other side to decompose for the next year. so, in fact, the compost ends up being between 1 and 2 years old. it's frozen for a good 4 months of the year, so we don't touch it, but in the other 8 months, it gets turned 2-3 times when we feel like it. leaves tend to take a little longer for us to decompose, so we try to not use too many. in the pictures, you can see them on top and bottom of the piles for insulation.