I have wanted to cast a Celtic bronze sword for some time but I didn’t want to use the modern methods. Playing with the idea in my head I ran across a primitive kiln that was completely made from clay for firing pottery. It is a bottom fired kiln with the ability to have more fuel added when needed. That ability would cure the ills of my last charcoal fired smelter as it was just a bit too small to finish melting the crucible of bronze.
To make the kiln I started digging out clay and screening it with a framework of two by fours with a section of hail screen across it just a bit bigger than a five gallon bucket. Spending a bit of a morning digging and screening clay I felt a bit like an archeologist looking for pot shards. Dumping the gravel sized rocks into another bucket to fix some soft spots in the drive, and moving the bigger rocks for the base of the kiln and to repair my wood fired oven, I soon had several buckets of good Kansas clay ready.
I had a partial bucket of sand and one of water ready to make the fire plate for the kiln. An empty bucket, a splash of water and some clay added until I had a thick dough like mix. I added sand, clay, and water until I figured I had close to enough of a mass of clay to make a plate about two inches thick and 18 inches around.
Once I had a large ball of the clay sand mixture I dumped it out on a large piece of cardboard. Kneading the thick mess into a pie that reminded me of a Godfathers pizza we used to get as a teenager but not nearly as tasty looking, I then poked a bunch of holes in it with my finger. This was how the heat from the fire under the plate would get into the firing chamber. Then I used a smaller dowel rod to add smaller holes in between the bigger holes poked by my finger. The trick is to get as many holes as you dare without compromising the integrity of the fire plate.
Now if Murphy goes back to copilot for my friend CJ I won’t have to remake the plate. Then having let it dry for about 10 days it is hard as woodpecker lips but still vulnerable to water the first firing will take care of that when it hits 1200 deg or so. Next to screen more clay and make a mold for bricks to make the tower of the kiln.