How to use a Bokashi bin
Measure and mark where you want the compost bin to go. The redgum sleepers make it too heavy to move once it's made. Also, be sure to leave enough working room for wheelbarrow access.
Our compost bin is two sleepers high and the back is 2300mm long. Measure, mark and cut the four sleepers for the back of the bin using the circular saw. Don't forget to wear safety gear when using the circular saw.
Measure and mark the eight dividers for the compost bin, each one should be 700mm long. Measure and mark for the two front guides, they're 420mm long. Cut the dividers and the guides with the circular saw.
Lay out the back piece and the sides at both ends. Then pre-drill with the 4.5mm drill bit before screwing into place with two x 100mm galvanised batten screws. Use galvanised screws because they won't rust.
With the sides in place, measure and mark for the two dividers, ours measured 700mm between each bin. Put the dividers in place. Pre-drill with the 4.5mm drill bit and screw into place with 100mm galvanised batten screws. If the compost bin isn't in place, have a friend help you move it before attaching the second level of sleepers.
Repeat the previous steps to build the second level of the compost bin.
Place the two 420mm guides at the front of the two centre bin sections. As well as being guides they also help to hold the frame together. Pre-drill with the 4.5mm drill bit and screw into place with the 100mm batten screws.
Now it's time to cut the timber for the front guides. Take a 420mm x 200mm piece of timber, then measure and mark a line down the centre. Clamp and cut the wood with the circular saw.
Measure, mark and cut your sleeper into 50mm widths using the circular saw. You need to make six of these. Clamp the timber to a workbench to make sure it's secure while cutting.
Take the 100mm front guides and put them in place. Pre-drill with the 4.5mm drill bit and screw into place with 100mm batten screws.
To fix off the inner guides that will hold the gate, use a 700mm sleeper as a spacer and allow a 10mm gap to ensure the gate doesn't stick. Pre-drill with a 4.5mm drill bit and screw into place with 100mm batten screws. Repeat for the two other compartments.
Now it's time to measure, mark and cut the gates. Ours measured 700mm but it will depend on the size of your compartments. Once you've cut them, slide them into place.
We attached a lid to cover two of the three stations of our compost bin. Ours was made from 19mm formply cut to 1550mm x 870mm. Formply is ideal because it's water resistant and will keep the bin dark. Hinging is a good idea because it gives easy access to the bin. We screwed 40mm screws into the sleeper and 16mm screws into the formply on the top.
Start with a layer of straw mulch, some garden compost and kitchen or green scraps in the first station in the compost bin. Continue to layer straw and green scraps. Keep the compost aerated by giving it a regular stir. Move the compost from one station to the next as it decomposes. When it reaches the last station, it's ready to go onto your garden.
Now you've made your compost bin, you can start recycling food scraps to benefit your garden. It's not only good for your soil, it's environmentally friendly as well.