Primitive Technology

The brick hut was destroyed by a falling tree. It had lasted 2 years and 8 months and would have lasted quite a bit longer if it were not for the accident. I recovered the tools and materials that were in the hut and then salvaged the bricks and tiles from it that were still intact. A large pile of about 750 bricks was stacked up to be used in other projects. Also in this video I show how the other huts in the area are in the wet weather. I do maintenance on the roof of the most recently completed one as it needed a beam replaced due to rot. I'll most likely build something with the salvaged bricks when the weather becomes drier so I can calcine ash to make mortar.

I tested a fly wheel on the blower

I took the iron I already smelted and re- smelted it. The iron was old and rusty from forging experiments. Iron oxidises faster when in the forge due to the hot and oxidising conditions. So I tried smelting it again to turn the rust back into iron. The first attempt involved charging the iron into a furnace in a single charge. The results were mixed, the iron was in separated pieces though the iron was softer and could be slightly cold forged. Next the iron was included in an iron smelt with fresh, roasted ore. 3 charges of ore were charged, then the scrap iron and then another 3 charges of ore. The result was cleaner but the iron was still in separate pieces.

I tested a charcoal retort based on the Hookway retort method using only primitive materials. A normal retort is one in which the sealed chamber of wood is inside a furnace and the heat drives off the volatiles converting it to charcoal. The Hookway retort, invented by James Hookway (see original video: • The best charcoal retort kiln in the ... ) has furnace, a metal pipe, inside the sealed chamber of wood, so the heat conducts out into the wood converting it to charcoal. In addition to this, escaping volatiles from the wood enter the pipe where they are burnt, adding further heat. After a while, no more wood is added to the furnace as it runs entirely of wood gas. In my version I made a clay pipe and tested it. It did produce some charcoal but most of the wood remained unburnt. This was due to the poor heat conductivity of the clay pipe relative to the metal pipe of the original. The charcoal it did produce from wood touching the clay pipe directly, was of excellent quality. An

Certo, ecco il riassunto ancora più sintetico, mantenendo le persone verbali originali, questa volta in inglese: --- I built a **belt and pulley drive** for a blower because the previous rope-and-stick system limited RPMs, producing only low pressure and non-solid blooms. The belt allows continuous rotation and higher RPMs. I tested **clay wheels** (heavy but the small one worked) and **cane wheels** (lighter, but with mounting issues). A "floating" cane version worked better, but isn't scalable. Current wheels (25 cm) give 1:10; the new system should reach 1200 RPM (from 960). 50 cm wheels would give 1:20. Future experiments are needed.

I built two water bellows to use in tandem for smelting. Previously I made and tested one water bellow. It was small and was fired in a pit. For this project I made two that had a deeper stroke than the last one. I also fired it in a kiln so it would be stronger. I made a wide based tuyere for the two spouts of the bellows to fit into during use. When one bellow was lifted the other dropped so that a constant but intermittent stream of air entered the fire. The bellows worked well initially but then the handle came off one. So I attached wooden handles to both and they were easier to operate. I got about 2 hours of use and then the spout broke off one. This was probably due to a low firing temperature in the kiln, I could fix that problem the next time I do a firing by adding fewer layers of bricks in the bottom of the kiln. Also, the design could be modified to make the spout stronger.

I made mortar from wood ash and crushed terracotta and then used it to mortar bricks together. The ash from previous brick firings was formed into pellets and re-fired in the kiln to calcine it. There is calcium in wood ash which behaves the same as limestone when burned so it will set after being wetted and allowed to dry. The aggregate was crushed terracotta from old broken bricks. These contributed alumina and silica which along with the sodium and silica from the ash form aluminosilicate chains, forming a geopolymer. It forms a noticeably stronger mortar than the previous on I made from wood ash and sand. Also the terracotta is easier to source than sand in this location. Mixing 1 part ash to 3 parts terracotta yielded a useable mortar. A sample was tested after 9 days of drying and did not dissolve in water. I'll likely investigate easier ways to produce this material in future so I can build more structures with brick.