RRFB Wood-and-Wire Three-Bin Turning Unit

Wood-and-Wire Three-Bin Turning Unit

A wood and wire three-bin turning unit can be used to compost large amounts of yard, garden, and kitchen wastes in a short time. Although relatively expensive to build, it's sturdy, attractive and should last a long time. Construction requires basic carpentry skills and tools. With optional lids and bottom, this unit can be made rodent-resistant.

Building a Wood-and-Wire Three-Bin System

1. Cut two 31 1/2-inch and two 36-inch pieces from a 12-foot length of 2x4 lumber. Butt-joint and nail the four pieces into a 35-inch x 36-inch "square" Repeat, building three more frames with the remaining 12-foot lengths 2x4 lumber.

2. Cut four 37-inch lengths of hardware cloth. Fold back the edges of the wire 1 inch. Stretch the pieces of the hardware cloth across each frame. Make sure the corners of each frame are square and then staple the screen tightly into place every 4 inches around the edge. The wood-and-wire frames will be dividers in your composter.

3. Set two dividers on end, 9 feet apart and parallel to one another. Position the other two dividers so that they are parallel to and evenly spaced between the end dividers. Place the 36-inch edges on the ground. Measure the position of the centres of the two inside dividers along each 9-foot edge.

4. Cut a 9-foot piece from each 10-foot length of 2x4 lumber. Place the two treated boards across the tops of the dividers so that each is flush against the outer edges. Measure and mark on the 9-foot boards the center of each inside divider.

5. Line up the marks and and through each junction of board and divider, drill a 1/2-inch hole centred 1 inch from the edge. Secure the boards with carriage bolts, but do not tighten them yet. Turn the unit so that the treated boards are on the bottom.

6. Cut one 9-foot piece from the 10-foot length of construction-grade 2x4 lumber. Attach the board to the back of the top by repeating the process used to attach the base boards. Using the carpenter's square or measuring between opposing corners, make sure the bin is square. Tighten all the bolts securely.

7. Fasten a 9-foot length of hardware cloth to the back side of the bin, with staples every 4 inches around the frame.

8. Cut four 36-inch-long pieces from the 16-foot length of 2x6 lumber for front runners(save the remaining 4-foot length).Rip-cut two of these boards to two 4 3/4-inch-wide strips. (Save the two remaining strips.)

Materials

four 12-foot lengths of 2x4 lumber

two 10-foot lengths of 2x4 lumber

one 10-foot length of construction grade 2x4 lumber

one 16-foot length of 2x6 lumber

six 8-foot lengths of 1x6 lumber

a 22-foot length of 36-inch-wide 1/2-inch hardware cloth

16d galvanized nails(2 pounds)

poultry wire staples (250)

twelve 1/2 inch carriage bolts, 4 inches long, with washers and nuts

one quart wood preservative or stain

Optional materials - for the lids and bottom

one 4x8 foot sheet of 12-inch exterior plywood

one 4x4 foot sheet of 1 2-inch exterior plywood

six 3-inch zinc-plated hinges

twenty-four 3/16 inch galvanized steel bolts, with washers and nuts

sufficient galvinized sheet metal to cover bottom of bins

Tools

tape measure

hand saw or circular power saw

hammer

tin snips

carpenter's square

drill with 3/16-inch and 1/2 inch bits

screwdriver

adjustable wrench

pencil

safety glasses, ear protection, dust mask, and work gloves

9. Nail the 4 3/4-inch-wide stripes to the front of the outside dividers and baseboard so that they are flush on the top and the outside edges. Centre the two remaining 6-inch-wide boards on the front of the inside dividers flush with the top edge and nail securely.

10. Cut the remaining 4-foot length of 2x6 lumber into a 34-inch-long piece and then rip-cut this piece into four equal strips. Trim the two strips saved from the step number eight to 34 inches. Nail each 34-inch strip to the insides of the dividers so that they are parallel to, and 1 inch away from, the boards attached to the front . This creates a 1-inch vertical slot on the inside of each divider.

11. Cut the six 8-foot lengths of 1x6 lumber into eighteen slats, each 31 1/4 inches long. Insert the horizontal slats, six per bin, between the drivers and the vertical slots.

12. (Optional)Cut the 4x8 foot sheet of exterior plywood into 3x3 foot pieces. Cut the 4x4 foot sheet of the exterior plywood into one 3x3 foot piece on one of the three bins and attach each to the back, top board with two hinges.

13. (Optional)For complete rodent protection, cut sheet metal to fit bottoms of bins.

14. Stain all untreated wood.