Primitive Technology

I made a fish trap from cane and tested it over the course of a year catching various aquatic animals. Initially, I intended catching eels with it but instead it caught fish, crayfish and even a fresh water crab. These were then released back into the wild. This type of trap is made in two parts, a basket and a funnel. The funnel is inserted into the the opening of the basket so that animals venture into the trap easily but have difficulty exiting. The trap requires no bait to work and can be reused over as long as it's intact. The video also shows the huts in the rain season.

I tested the one-way spinning blower in an iron smelt and it is more effective than the previous both way spinning blower. Using the same amount of ore and charcoal, the original blower yielded 30 g of iron where as the new blower yielded 51 g. The previous all time record was 41 g from several years ago but the new blower it beat that by 10 g on its first run. The energy saved by having the fan spin constantly in one direction no doubt contributes to the better performance of the blower. As with the old blower, the new one produces high carbon iron prills (cast iron blobs) in slag. The brittle slag crushes easily while the iron prills remain intact to be picked out by hand or gravity separated with panning. The iron prills were also quite large and more numerous than smelts done with the old blower.

The thatched workshop where I produce bricks, pottery, cement and charcoal for various projects was destroyed by prolonged rain from the wet season. Built less than a year ago, the thatch had deteriorated due to moth larvae and mold consuming it. The rain got through and rotted the lashings holding the roof up and it collapsed. In contrast to this, the brick and wood ash cement hut still stands after 2 years due to the permanent building materials. A second smaller thatched hut was built to continue the brick making process but even that was made difficult by the weather with that thatch rotting in less than a month. In the long term, a workshop made of permanent materials, similar to the main brick and wood ash cement hut, will have to be built in order to continue production of ceramic materials. The problem is that there needs to be such a structure to produce the building materials needed to build that very structure.

I have made wood ash cement before under the assumption that it was the calcium in the ash that gave it its cementitious properties. It may however be a type of geopolymer cement, where the cement is activated by and acid or a base (in this case a base). The acronym NASH is used to remember the material needed: sodium, alumina, silica and H2O. All of these are present in the materials used here. I did some experiments to see how to produce the cement using ash and fired clay from broken bricks. The first method was to take ash from a cold fire and form it into pellets. One pellet was left aside to dry while the others were calcined by firing them in a forge with wood. The calcined pellets were then mixed with terracotta in different proportions (ash: clay 1:0, 1:1, 1:2, 1:3). All samples survived a water test after setting for a week except for the sample made from cold ash that had not been calcined. This demonstrates the need to calcine the ash at a high temperature before use. Next

I made charcoal in a clay pot by putting wood in it and heat the pot externally effectively making it like a retort. Previous methods of charcoal making directly heat the wood by burning a portion of it to create the charcoal. But this method applies the heat indirectly to the wood with it completely sealed off from oxygen. The wood successfully turns to charcoal on a small scale but fails to scale up due to the larger pot cracking during the firing and letting air in which burns the wood to ash. The theory is sound but more work needs to be done on the pot to stop it from cracking.

I made a hashbrown from Polynesian arrowroot. A hashbrown is typically made from potatoes where it is mashed and baked on a pan. Here I made it from wild growing Polynesian arrow root instead of potato. I'd made Polynesian arrowroot starch before but this time I cooked the mash along with the starch. It made a sort of gelatinous pancake, similar to dishes made with cassava. The mash needed soaking in water to eliminate bitter compounds that make it unpalatable. The pancake was starchy and still slightly bitter due to time constraints but would taste better if soaked and drained more times. It would make a good famine food if none other were available as the starch is high in energy.

I built a Water Bellows. It’s an upside-down clay pot with an inlet valve and an outlet spout. The inlet valve is simply a hole in the pot with a leaf plastered to the inside with wet clay so that it forms a one-way flap valve. When pushed down into water, the valve shuts and air is forced out of the spout and into the fire. When the pot is lifted in water, air is sucked in through the open inlet valve and the cycle repeats. I got the idea from a Food and Agriculture Organization website I saw years ago. A Google image search for “FAO water bellows” gives an image of someone using a more complicated version at a brick forge in Zimbabwe, possibly from 1994, but I can no longer find the original diagram or description. From memory, the air and water containers were steel drums and there was a U-shaped pipe to convey the air down from inside the air drum when lowered, through and out the water drum and into the fire. Air entered an inlet valve in the top of the air drum when lifted. The

With the wet season only 2 months away and thatch being an impermanent material, I needed to make more roof tiles for a new hut that will withstand the next deluge. The only existing hut I have that weathers the rain well is my brick and tiled hut. Previously I put most of my effort into brick making, but decided that roof tiles are more valuable in the short term as they can be used on a mud walled structure and will last as long as the mud and timber stay intact. But to make roof tiles I needed a large shelter to protect them while being made and drying. Previous workshops I built to house brick and tile production were large thatched huts on posts. These huts took a long time to build ranging from 3 to 5 weeks and requiring more timber. This time I built an A-frame hut for the same task. It only took 10 days to build and covered a large floor space, 4 x 4 m. If the job of the shelter is to only house materials then tall side walls are not necessary, only a large floor space.

I built Mud walls and capped them with roof tiles to protect them from rain. Mud walls if left uncovered in wet weather will dissolve in the rain and collapse. I wanted to test a solution to this problem by covering the walls with roof tiles. I start the video firring the roof tiles made in the previous video before making another batch to dry out ready for firing. Then I started building the mud walls by digging a foundation trench and filling it with rubble. The rubble was then capped with large stones completing the foundation. This was done so that water at ground level wouldn't wick up the mud wall and weaken it. The mud was then made from water and soil around the build site. The mud was then piled in layers about 5 cm thick and 25 cm wide to form 2 opposing walls 2.25 m long. When the wall was 75 cm high, the bricks were laid on one side of the tops of the walls and the tiles put on these in such a way as to give them a 30 degree slope. It then rained on the walls without ill ef

I built a hut with two gabbled end walls made of mud, supporting a roof of wooden poles covered with fired clay barrel tiles. The video shows the entire project which took 2 and a half months of work. It begins with the making of a thatched A-frame hut as a workshop for making tiles. The tiles were made from clay and fired in a kiln made from bricks made in previous videos. A 2x2 m hut was then built by making two walls of mud in the shape of a wall and gable. Between 1.25 and 1.6 tons of soil were used to make these walls. The roof was formed by spanning the two walls with timber that was then covered with tiles. The hut shed rain reasonably well but it remains to be seen how it will fair in the long wet season which is starting now. The main benefit of this hut is how little material is used in the walls considering that there are no side walls, significantly reducing labor and materials. It will be an experiment in how this building method works.