How to make a rotating compost bin

If you want a faster composting bin you might give this clever rotating bin a whirl.

You will need: a 200-litre plastic drum, four 100mm x 100mm x 1.8m H4 treated posts for the legs, two 1200mm lengths of 100 x 25 treated pine for cross braces, a skilsaw or handsaw, chisel, 10mm & 25mm paddle bits, 4mm drill bit, two M10 x 120mm coach bolts, Jigsaw and blades, two 64mm hinges, screwdriver, small bolts and nuts, rivets and rivet gun, offcuts of 7mm ply or similar, two 50mm barrel bolts, plastic downpipe or aluminium for internal fin, one 25mm x 2m aluminium tube and a hammer.

Cost: $120, excluding drum and stain.

Instructions

Step 1 how to make a rotating compost bin

Step 1
Measure up 1030mm from the base and cross 2 of the 100mm x 100mm posts over each other so that the space between the legs at the base is approx. 950mm. Mark each side of the posts where they cross. Repeat for the second set of legs.

Step 2 how to make a rotating compost bin

Step 2
Set the skilsaw blade to 50mm and create multiple cuts between the marks. Score with the chisel on the side of the timber at the base of the cuts. Chisel out the excess and tidy the cut-out.

Step 3 how to make a rotating compost bin

Step 3
Put the legs together, drill a 10mm hole in the centre of the cross and join with a coach bolt. Trim the feet. Measure and mark 320mm up from the top of the cross and trim the top of the legs on an angle.

Step 4 how to make a rotating compost bin

Step 4
Mark the door. Drill a start hole where one of the hinges will sit and using the jigsaw carefully cut out the door.

Step 5 how to make a rotating compost bin

Step 5
Mark the centre of the top and base of the barrel and drill a 25mm hole. Take the bungs out of the barrel to allow for air intake.

Step 6 how to make a rotating compost bin

Step 6
Attach the hinges to the door with bolts or rivets. Cut a strip of ply 30mm wide and long enough to extend past the width of the opening. With the ply level with the top edge of the door cut out, attach the hinges to the barrel, screwing through the ply. Attach the barrel bolts to the door with bolts or rivets. Place the second ply strip extending about 10mm into the opening and attach barrels for the bolts.

Step 7 how to make a rotating compost bin

Step 7
Cut the downpipe in half and attach one edge to the inside of the barrel to act as a fin. Stain the legs and cross braces. I used Resene Woodsman Penetrating Oil Stain in Resene Evergreen. Allow to dry. Attach the cross braces to the back legs. Feed the aluminium pipe through the holes in the barrel and place into the V of the legs with the door flap opening downwards.

Toss in a mixture of garden waste and kitchen scraps. Chop or shred the material as smaller pieces break down more quickly. Don't overfill. If the drum is too heavy it won't turn easily. Spin 4-5 times daily to mix and aerate. The contents will heat up which aids decomposition and kills weed seeds.

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