3-stage composter - Weekend Project

Sunset, March, 2003 by Peter O. Whiteley

This compost center is as handsome as it is hardworking. It features three bins (for three-stage composting) framed by rot-resistant composite wood decking and screened with galvanized wire mesh. Tall fence posts at each corner of the bins attach to the sturdy arbor top.

The detail below shows the basic frame forming one side of a bin. You'll need to build 10 such frames; 3 will be 1/2 inch narrower to serve as gates. Intermediate woodworkers can build the center in about two days. Materials cost about $450. You can make a smaller center by building fewer bins.

Building it

Materials

NOTE: All members except posts and 2-by-2 are composite lumber (we used Trex).

8 eight-foot-long 4-by-4 fence posts
5 ten-foot-long 2-by-6s
3 ten-foot-long 2-by-4s
2 twelve-foot-long 2-by-6s
4 eight-foot-long 2-by-4s
3 six-foot-long 1-by-4s
1 four-foot 2-by-2
1 gallon of solid-color acrylic
latex wood stain
200 3-inch deck screws
50 1 1/2-inch deck screws
25 feet of 36-inch-wide,
1/2-inch-square galvanized
wire mesh (fence cloth)
1 pound of fence staples
6 three-inch galvanized
butt hinges with two screw holes
3 fence handles
6 fence barrel bolts

Tools

Circular saw, electric drill, tin snips, tape measure, hammer, framing square, post-hole digger, shovel, and level.

Directions

1. Stain the posts.

2. Rip the 10-foot 2-by-6s in half, creating ten 2-by-3s. From seven 2-by-3s, cut two 27-inch and two 31 1/2-inch lengths. From the other three, cut two 26 1/2-inch and two 31 1/2-inch lengths. Build 10 frames, using screws to secure butted joints.

3. From the 10-foot 2-by-4s, cut, center, and screw tops to frames.

4. Cut wire mesh and staple to overlap the 2-by-3 frames.

5. Cut the 12-foot 2-by-6s to 11 feet, and cut a 3 1/2-inch by 12-inch right-angle triangle off each end.

6. Cut the 8-foot 2-by-4s to 4-foot lengths and taper ends starting an inch from the top, using a scrap triangle as a guide.

7. Attach a 27-inch-wide frame between two posts so the bottom is 12 inches from the posts' ends. This makes the basic framing module. Repeat to make three more.

8. Determine location of compost center, and starting at one end, dig two 12-inch-deep holes, then stand the first module in the ground, with the wire mesh facing what will be the inside of bin. Check that posts are vertical, then backfill holes. Tamp.

9. Screw a full-size panel to the side of the first framing module, checking squareness and levelness.

10. Dig the next two holes, then position, square, and secure next module, repeating step 8. Before filling holes, check that width of open end (where the gate will be) is 27 inches. Repeat steps 8, 9, and 10 until all modules are in place.

11. Center the 2-by-6s so the top edges are 3 1/2 inches below the top of the posts. Attach with two screws per post. Flank post tops with pairs of 2-by-4s so ends extend equally.

12. Add hinges 3 inches from top and bottom on one side of gate panels, and barrel bolts on the other. Attach gate and handle with 1 1/2-inch screws.

13. To make slatted top, cut 2-by-2 in half, then cut 1-by-4s into six 30-inch lengths and screw the ends to the 2-by-2s.