I have wanted to make a kiln for a while now and I wanted to do a primitive wood fired one. The other goal was to keep it cheap as possible. That being said I realized that it would be a lot of sweat and time involved, hopefully without to much blood being shed in the process. I have a good source of clay behind my house so I knew with a bit of effort with a garden pick and a shovel the raw material wasn’t the problem.
From past experience I knew that the clay was extremely rocky with much fine stone through it. The fine rocks didn’t bother me as I kind of figured they might actually help make the bricks stronger when they were dry. It was the bigger chunks that were going to be the pain. Now as a young kid I remember the farm houses having a heavier screen that fit over the windows that the oldies called hail screen, it had about one quarter of an inch square holes and was fairly rugged. They used it to protect the windows from hail in the earlier part of the 20 century. Now knowing what it is and trying to find it in the modern box home supply stores being staffed by gaggles of ignorant teenagers and young adults might prove to be rather lively. On my first day off after pulling the trigger on making the kiln I headed off to Lowes, being somewhat of a stubborn bloke I walked that big arse store for quite some time trying to find it on my own, before I finally asked where it was located. Having to explain what it was they said “oh I know where that is” then proceeded to head for the window screen, when I said, no, this is not it I then had to explain again what it was. We went to the manager and through the process again. We did this in several different sections until finally getting to the garden section and the young little girl knew exactly what I was looking for. Getting directed to the dark corner clear in the back that looked like a junk heap was a couple of shelves with some chicken wire and heavy mesh. Hidden amongst that were a few rolls of hail screen, alas some luck my way, needing nothing else I made my way home to make the shaker.
At home I dug out some 2 x 4s, sheet rock screws and gorilla glue to make the framework, I decided to make the frame just a bit larger than a five gallon bucket so I cut the boards to inches adding the width of the notch in each end. The idea was to make a square of the 2x4s with a screen bottom that just fit on top of a five gallon bucket. I notched the ends of the boards so the glue and screws would have a better hold. After letting the frame dry I cut the hail screen about a half an inch short of the total width, it was then screwed down with the sheet rock screws.
Now for the fun part, the digging, I have never been a fan of digging holes. It turns out this is no different. Starting with a little garden pick and an entrenching tool as it is easier to use amongst big rocks, I started breaking loose a pile of clay and stones. Normally I prefer to dig rocky soil with shaped charges and a cratering charge but that is no longer an option and I wanted to keep it somewhat traditional. The screen bottomed box did its job quite nicely separating the stones from the clay. I used two five gallon buckets, one for the stones, and another for the clay. The screen bottom box went on top of one bucket and a couple of shovels full of loose clay was loaded in, then the box was given a brisk shake until all the fine clay had fallen into the bucket. Rocks to big for the drive are into another pile for other uses, and then the remains in the box are dumped into the other bucket. I filled them at a steady rate, the stone and clay running about the fifty percent rate. My driveway was getting a few soft spots so slogging the buckets full of stones out there soon fixed that. The bigger rocks are being used to repair the wood fired oven the spring rains damaged. It’s amazing how much lighter the clay bricks are when dry then fired for bricks that will be out in the weather. The unfired bricks will turn back into a clay mud pile with to much rain so a cover will be required until it is burned and cured through.