This corner is quite square, more a tribute to the cuts that have been made than the necessity for perfection. Get them as close as you can without being too anal about it. Corners with the wood securely abutting to one another even if a degree or two off will be stronger than perfectly square corners with the wood pieces making gaps.
All five frames of the bin are finished, two ends and three seperators, all identical. Now they need to have something over the sides to cover them so that the compost material will not fall out. In the past I have used
- fencing: not my favorite as it was not rigid enough and made it awkward to work the sides of the bins.
- heavy wire fencing might be really good but I have not used it
- wood mesh used for fences
- great stuff, cheap and lasting, the last bin had mesh sides and lasted years
- boards
- great stuff but expensive unless you have some free ones around
Thankfully, I recently had to tear down a section of fence that had seen better years about ten years back. Some of the boards were rotted so badly they are just due for the recycle but otheres were ok once I cut off the rot. There should be enough to work out the needs for a compost bin or in this case, four. What I really want are four bins in a row.
Four bins three feet wide each mean the boards along the back of the setup need to be twelve feet long. I took some short pieces of board and attached them to longer pieces to make up the twelves that were needed. No fancy joinery here. All I did was fasten the two boards together with another short board overlapping the butt joint. Simple and effective.
All I did for the frames was to cut three boards to fit each one and fasten them in place. Note the gaps between the boards. Air needs to reach the compost pile so the gaps are needed. I have left about an inch but two would be fine. There is seldom a problem with the compost actually leaking out.
Now for balancing game as the whole thing comes together. The easiest place to put the compost bin or maybe " compost factory" together is the place where it will be used. Each frame is stood up three feet apart and the twelve foot boards are screwed to the back so as to hold it together. Actually, the frames are oriented so the back is up in the air while the boards are fastened to it. In my case it was just easiest. While it is hard to tell from the picture, I used clamps to hold the boards in place and hence hold the balance while I screwed the boards down. You can see one on the second frame from the right.