After everything was assembled, one of the doors I had made for the compost bit was a smidge fat.  Thankfully, I brought my #4 plane with me, and I took a few shavings off until it fit correctly.


The doors needed a couple of bolts each to make sure that not only do they stay shut, but also that kids/critters (there’s a lot of overlap) don’t get into the piles to root around.


Once the frame was complete, it was a long slog to get the poultry net affixed to it.  There are over a thousand staples (stainless steel so as not to be corroded by the treated lumber) in this bin.  I fired them with my old Arrow staple gun, and by the time I was done, I had to take a couple of days to recover because my hands were so worn out!


The last thing is to put 18″ long rebar pins through the skids.  There are a dozen of them, and they keep the bin from sliding down the hill.


And we are done!  The bin presents a fairly non-threatening appearance when closed…


…but when open, suggests that you could dispose of almost anything.  They’re still looking for Hoffa, right?



Into left field

When we last saw our compost bin project, it was at the end of the shop phase of the construction.  Now, it’s on to the field install portion.  The part I haven’t shown you is loading the multitudinous amount of supplies, from staples to hinges to handles that needed to be loaded.  Nor did I document the rather tedious exercise of carrying all those completed frames and hatches and 12′ long 2×6’s out the back of the garage and around the house to get to the pickup.  Admittedly, it would have been faster to just open the overhead garage door and go out the front, but I sort of have a pile of lumber sitting on it.  Bother…

But when I  did get to the site, the pile of lumber in the truck started to come together.  All of the subassemblies had been marked, so I arranged them in their proper order and attached the rear spine into the recesses we cut last time.  It can get a little precarious at first, but it worked out in the end.  Bringing a few clamps from the shop really helps.


Once the rear spine was in place, I attached the bottom skids.  These did not get recessed because I wanted them to be below grade.  When you’re emptying the bin, once you get to the skid, you know to stop and not dig a crater under the bin.  Once the skids were in place, I could move the whole bin away from the truck, and into place.  It can take a while to maneuver something this big by yourself, and without breaking things to boot!


The last 2×6 goes across the top rear of the bin to act as a hinge rail.  This way we can put the stress on the whole 2×6, not just the frame.  Then, hinges go on the hatches and two of the doors.  It’s the middle door that gets a little different treatment.  See, no matter which way we hinged it, it would be in the way during the transfer from one of the other bins.  So I used a pintle hinge.  Remember if you will that we had to make the middle door a little bit differently, with two braces instead of one?  That’s so the female part of the hinge could get bolted  into the brace with a 3/8 carriage bolt, since even the smallest one was longer than the frame was wide.


Two pintles on either side, combined with a lifting handle, means that the door can be lifted straight up off the bin and placed to the side when you’re rotating bins.  Yet, when the female parts of the hinge are slid onto the male portion that stays in the frame, it is held securely.  This might not seem like a big deal, but each of the bins holds roughly 64 cubic feet of compost.  If you can save a couple of steps on every forkful, every time you turn your compost, it adds up to a lot less work, and less spillage.



Once the frames were all lapped together (4 frames, 4 corners, 2 sides to the joint, 2 cuts per side is 64 different saw cuts just to get the frames up.  Whew!), I had to make the top hatches, which were 6 feet long and 4 feet wide.  They are constructed in a similar manner: another 32 saw cuts.  Then  I had to put the braces in on the frames and on the hatches.  These are a form of half-lap that, since it’s not on a corner, is also known as a crossing or halving joint.  It’s fairly similar to our previous joints on the male end, but the female end requires a chisel and is best cleaned out at the end with a router plane.


As with the corners, they are secured with a weatherproof adhesive, and heavy duty (treated lumber approved) screws.  There are six braces so far, and every one of them requires 4 saw cuts.  Add another 24 saw cuts to the running total.


Finally, I had to make the doors.  There are three doors to this bin agglomeration.  The stated idea is that you can flip compost from one bin to the other to aerate it and make it turn from a bunch of kitchen muck into a proper soil amendment faster, as adding the oxygen from aeration increases the rate of microbial activity.  Science!

To fit in our 12′ length, our doors have to be slightly less wide than they are tall to make room for the skeletal framework.  Not enough to be apparent at a glance, but enough that if you aren’t paying attention, it would be tricky to rework…


Each of those doors, constructed similarly to the frames, has its own set of joints.  The middle door has two braces, to account for some hardware mounting issues.  So, this adds another 72 saw cuts to our total.

Finally, the frames are cut for the reinforcing spine.  This spine is two 2×6’s that are going to be housed inside the frames for better rigidity.  This is best handled by clamping all the frames together and doing a gang cut on them.  This ensures that they will all be in the same plane.  It takes awhile to cut through six solid inches of yellow pine, but do persevere.  It’s best in the long run.  Again, I cleaned out the bottom with a router plane to ensure accuracy.  And this last bit (with another 20 cuts) will wrap up the shop portion of the build.  Next time, we’ll start on the field install.


In case you were curious, but didn’t want to count, this project has required 212 accurate saw cuts to get to where we could start really putting it together.  Thankfully, I was able to get it done before my saws went on strike for better working conditions…


Our new project for the week is a little different from the commissions I usually get.  I got an email from a lady who had seen my work at City Folk’s Farm Store, and wanted me to build her a compost bin.  Not just any compost bin, but one that was 12′ long, with three 4′ bins, complete with hatches and latched doors to keep the critters out.  I said I could do that (though my own bins are considerably more shabby), and drafted a design.

Dealing with the pressure-treated lumber that this bin is made from had a few considerations in the construction.  The joints used in this project are important because they allow for the strongest attachment of the sides, but they will open up over time because pressure treated lumber is extremely wet.  As it dries, it will shrink.  Also, be aware that there will invariably be variations in the size.  Though all of the 2×4’s will nominally be 1.5″ x 3.5″, I experienced a variation of ±1/8″.  This can be a problem if you use the nominal size as your standard.  Be sure to use superimposition to lay out your joints.

The joints in this particular project are almost entirely half-laps.  It’s a lot of fairly tedious cutting, but with a careful work, they will work off the saw, and not require further fitting.  It is fastest to use the big ripsaw, but you can use a large tenon saw if you have enough plate under the spine.


Once the half-laps for the frames are cut, they can be assembled, then put aside for the moment.  I’m using heavy-duty screws that are approved for use in treated lumber (important!), as well as a waterproof adhesive.  This one is almost done, three more to go!