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Worm Compost Bin

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worm compost bin
Difficulty
Beginner
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A worm composter can be kept indoors or out. Fill the bin with bedding, such as shredded newspaper or shredded dried leaves. Place some sand/dirt on top, put your scraps in a layer in the middle then cover with more bedding/dirt. When you add new scraps, dig in a little then cover them up again.

This design has two stacking units, but you can add as many as you want, depending on how much waste your family produces. The units fit into each other and lift up easily to rearrange or carry to the garden etc.

Fill the bottom tier with bedding, dirt, scraps and worms. As it fills up, start adding the material to the next tier. The worms should eventually move on up to the top when they run out of food in their level, leaving beautiful castings behind - perfect compost for your garden. When you empty the bottom unit into your garden, place it on top and start over, filling it as the bottom unit becomes saturated.

This is my first project from my own plans. I built it before improving the plans so my my actual worm compost bin that I built is full of flaws, but I've worked on it in sketchup and I think it's good to go now. You'll do a better job than I did.

Also, I used pine, to keep costs down and I finished it with a clear, food safe protective coat. Don't use paints or stains which could leech toxins into your compost. If you can fork out for cedar it will last much longer (and will look better too).

Don't judge the project by my photos of the completed one. I made lots and lots of mistakes. I think the final plans should be good though (maybe I'll make another one..). This is a fun way to compost. The kids will love it. Worms make wonderful compost that will enrich your garden. And they're lovely little pets too.

Keep it sheltered if possible, insulate in below freezing temperatures or move it indoors. It should be odorless, if you notice an odor, you probably just need to give it a stir to let some air in on the action.

Dimensions
worm compost dimensions
It stands 20 1/2 inches tall and is 14.5" wide and 14.5" long

Preparation

Shopping List

(plywood) 2'x4'
(1x2) 4
(1x3) 2
(1x6) 2
2 pieces of mesh, about 9" by 9" each
food safe protective coat (optional)
staples

Common Materials
2 inch screws
1-1/4" Pocket Hole Screws
Elmer's Wood Glue
Elmer's Wood Filler
Cut List

(Plywood) - 2 @ 14.5" X 14.5"  (or you can use boards stuck together with pocket hole screws and glue, especially if you want to use cedar for weather resistance)

(1x2)
  4 @8"
  6 @ 11.5"
  6 @ 11"
  2 @ 9.5"
  2 @ 10"
  4 @ 4 1/4"
  6 @ 14 1/2"

(1x3)
  4 @ 4 1/4"
  4 @ 14.5"
  4 @ 9.5"

(1x6)
  4 @ 14.5"
  4 @ 13"

Cutting Instructions

These dimensions are based on 1x2 boards being 1.5" in actual measurement and 1x3 boards being 2.5". If your boards are different size you will need to adjust some measurements.

Tools
Tape Measure
Speed Square
Pencil
Safety Glasses
Hearing Protection
Kreg Jig
Drill
Circular Saw
Staple Gun
General Instructions

Please read through the entire plan and all comments before beginning this project. It is also advisable to review the Getting Started Section. Take all necessary precautions to build safely and smartly. Work on a clean level surface, free of imperfections or debris. Always use straight boards. Check for square after each step. Always predrill holes before attaching with screws. Use glue with finish nails for a stronger hold. Wipe excess glue off bare wood for stained projects, as dried glue will not take stain. Be safe, have fun, and ask for help if you need it. Good luck!

Instructions

Step 1

Start making the main units. Use pocket hole screws and jig to make a box 14.5" by 14.5". Use wood glue. Make 2 of these.

Step 2

Next start making the bottom of your units. Fix your 9.5" and 14.5" (1x3) boards to one end of your units. You can make a square face with the (1x3) boards first using pocket holes and then screw or nail the face onto the unit, or you can just screw then pieces on one at a time.

Step 3

Next take your (1x2) pieces cut at 11" and 8" and set them 1 3/4" in from the edge. Again you can attach them to each other first with pocket hole screws to make it tighter if you wish.

Step 4

Staple your mesh using a staple gun or hammer and staples. Place the staples at about the midpoint on the (1x2) boards and fold up or trim off any excess mesh hanging off the edges.

Step 5

Step 6

To make the bottom/legs piece, take one 14.5" plywood piece (or boards screwed together farmhouse style) and fix the 4 1/4" (1x3) pieces on flush, using glue and pocket hole screws.

Step 7

Add the (1x2) leg pieces at right angle to the legs you attached in step 6. Screw them with pocket hole screws into the other leg and into the plywood base.

Step 8

Use pocket hole screws and glue to attach the (1x2) trim to the base plywood and to the legs.

Step 9

Fix (1x2) boards around the rim just as you did with your main units. This allows your units to stack into the bottom/leg piece. Your leg piece is complete.

Step 10

Now make your lid. Take your 14.5" plywood (or boards screwed together) and screw 2 (1x2) pieces 1 3/4" in from the sides. This will allow your lid to fit into the hole on the top tier.

Step 11

Stack your pieces on top of each other. Do not glue or screw or nail the pieces together. You want them to be able to be removed frequently and easily. They should sit in each other nicely. If it's too tight you can file or sand down as needed.

Finishing Instructions
Preparation Instructions
Fill all holes with wood filler and let dry. Apply additional coats of wood filler as needed. When wood filler is completely dry, sand the project in the direction of the wood grain with 120 grit sandpaper. Vacuum sanded project to remove sanding residue. Remove all sanding residue on work surfaces as well. Wipe project clean with damp cloth. 

It is always recommended to apply a test coat on a hidden area or scrap piece to ensure color evenness and adhesion.
Finish Used
If you wish to use a protective coat/stain, make sure it is safe for food contact. Look for the kind used for wooden spoons/butchers blocks etc.
Project Type
Outdoor Projects
Room
Outdoor
Style
Green or Eco-Friendly Style Furniture
Comments - Click to Display Comments

Comments

traciecook

Wed, 03/30/2011 - 15:22

This is great! I wanted to get into composting and now I have no excuse! 

Worm question - how many do you put in each bin?

niecey

Wed, 03/30/2011 - 22:52

The general advice is 2000 worms for 1 lb of food waste a day. If you have less food waste, use fewer worms. More food waste and you'll need more worms and you'll want to add more tiers probably. Or start using both boxes at once, (and sift out worms when harvesting the compost). Use red wiggler worms. You can order them online. They're the best kind for composting.

Kari Beth

Thu, 03/31/2011 - 06:38

Thank you for the plans!  Can't wait to get this going!

One question:  is there food waste that you do not put into your composte?

niecey

Thu, 03/31/2011 - 12:58

You should stick to vegetation, avoid meat products/dairy etc. You can put in crushed egg shells. The main reason to avoid meat/dairy is so you don't get unwanted visitors/critters getting into it. Plus it can contain dangerous bacteria etc. 

You can use horse waste/rabbit waste (herbivores). I personally put those in my tumbling composter and use the kitchen scraps for the worms. Apple cores/banana peels, ends of peppers, spoiled veg etc. It sits on my patio and is easy to get to, just a couple steps away from the kitchen. 
The worms will eat the dog poop and turn it into compost, but it can contain pathogens so definitely don't use it in your edible garden. For your flowers it should be ok. I might prefer to use a plastic bin though rather than wood for that, you can even dig a hole in the ground and bury a trash can with holes drilled in it, leaving just the lid exposed above surface, plop the worms (and bedding) in there and dump the doggy doo on top, through the lid. 

Christa (not verified)

Thu, 03/31/2011 - 17:07

Thank you so much for posting. Any idea on approx cost investment? I ask because I'm wondering how much more cost effective this would be from me buying a plastic one with a turner thingy. 

Thanks again! You're providing great info!

niecey

Thu, 03/31/2011 - 19:43

If you use pine and get the cheap furring strips and already have the tools you have do it for under $50. Less if you already have wood glue/screws etc. I can get the 1x2s for less than $1 a piece and the 1x3 for less than $2. The 1x6 are about $6.5 here and you need a couple. Then the cost of the mesh. It won't last as long as the plastic one though, because the wood will rot over time. Cedar would be better, but it costs more. I have a tumbling composter too and use it for my bunny poop, garden waste and like watermelon skin etc. The worm one gets used for potato peels, apple cores etc. I like the tumbling one too, it's very useful and it has the ability to catch some of the juices which seem to be very rich and helps my garden a lot.

Guest (not verified)

Thu, 04/07/2011 - 22:02

I keep a container beside the sind and chop up all my scraps into small peices after that the container goes into the freezer for 3 days.  This will kill all the fruit fly eggs and helps break down the food faster.  When I place my scraps into the composter I mix it 50/50 with shreddes paper and make sure there is always a couple of inches of shredded paper on top of the bin.

It be nice to drill a hole in the bottom to catch the worm tea,  this makes great fertilizer.

Guest (not verified)

Fri, 04/08/2011 - 13:05

You might try your local wood rehab stores. We buy a lot of lumber at the local habitat store. Then I keep things out of the land fill and my funds go to a great cause not some big corporation!

niecey

Sun, 04/17/2011 - 23:54

It shouldn't smell at all. I don't notice any odor from mine. If it smells you're probably just not burying the waste in the bedding well enough. Just place some of the shredded paper on top of the waste when you put it in the box. Or possibly it's too air tight, in which case, give it a stir and when oxygen gets in on the action you shouldn't notice a smell anymore. I've never had issue with smell from either my worm compost or my regular compost. It's not the same as like when a piece of veg falls behind the trash can and stinks for a week hehe. It's a whole wonderful living chemistry going on, breaking down the waste and turning it into rich fertilizer for your garden. I keep mine right at my patio door.

kerryandwesley

Thu, 01/19/2012 - 18:02

A friend who has been composting with worms for some time asked me where the liquid runoff will go in this set up. I have looked at plastic worm composters, and they all seem to have a spigot/runoff valve. Any thoughts here? Thanks!

Guest (not verified)

Thu, 02/23/2012 - 21:13

Drill a hole or two in the bottom of the base, put a screen over the hole, and place a drip pan of some form under the base. The runoff will flow through the hole and into the pan below.

Brenda Wright (not verified)

Fri, 07/27/2012 - 12:30

My worm bins must be kept cool, 50 - 72 degrees, in order for the worms to produce and stay alive. They can be kept outside in the winter, but I live in Texas, so they stay indoors.
Brenda