S2 E1 • New area starting from scratch

I bought a new property to shoot primitive technology videos on. The new area is dense tropical rainforest with a permanent creek. Starting completely from scratch, my first project was to build a simple dome hut and make a fire. First, I took some wood, Abroma mollis, for fire sticks. I knapped a small stone blade and used it to strip the fire sicks. Palm fibre was then taken for the tinder. The fire stick kit was then placed under a palm leaf to keep it out of the rain. Next, a stone from the creek was fashioned into a simple hand axe. This was used to cut a staff that was used to clear a path to the hut location. The location for the hut was a clearing densely crowded by native raspberry. This was then cleared using the staff and a small 2.5 m circle was levelled ready for building. Eight 2.75 m long saplings were cut using the hand axe and brought to the site. Eight holes about 25 cm deep were hammered into the ground in a circle 2.5 m in diameter and the saplings were then planted in. The tops were brought together at the top and tied with vine. A door lintel stick was lashed to the front about 75 cm off the ground giving a low door way. A stone flake was used to cut about 600 palm fronds. These were split and lashed horizontally to the frame creating a thatched dome. Mosquitoes are a real problem here so a fire was lit. The fire sticks from before had a hole carved in the base boards and had a notch carved to let the powder pour out. The spindle was twirled in the socket and smoking powder poured out producing a hot coal. This then ignited the palm fibre tinder. The fire was transferred to the hut and a small hearth was made of stones. The fire makes a big difference in the number of mosquitoes which seem unable to tolerate the smoke. The dome was completed up to the top and a small cap was made from lawyer cane and fronds to place on the top to keep rain out. When not in use the cap can be removed to let in more light like a sky light. Finally wood was cut for a bed. This consisted of wooden stakes hammered into the ground at the back of the hut behind the fire pit. Part of the bed frame is attached to the sapling uprights that form the dome. This works ok without the frame shaking too much due to the low attachment point of the bed. Wooden boards were then placed on this and were covered with palm fibre for bedding. Firewood is stored just inside the entrance on the left side of the door looking in. The bed sits behind the fire pit so smoke and flames deter insects or large animals reaching the occupant. Fire sticks and tools are kept just inside the right side of the entrance. The small hut is simple to build and creates a small, dry shelter for camping and storing tools. Though it is dark, the cap can be removed in fine weather to provide a fairly well-lit workspace protected from annoying insects. This new area has good stone, clay and materials lending themselves to elaborate shelters. A permanent creek runs through it. Mosquitoes are abundant here though and will be an issue. The Cassowary, a large, horned, flightless bird lives in this forest. It’s the most dangerous bird in the world, but generally only attacks when threatened.

Première diffusion : 24 novembre 2017

S2 E2 • Pottery and Stove

I made some pottery from the clay in the new area to see how well it performed. A large bank of clay was exposed by the side of the creek. I dug it out using a digging stick and took it back to the hut. Small sticks and stones were picked out of the clay and the whole mass was mixed to make sure there were no dry lumps. When this was done the clay was then left next to the fire to dry slightly so that it became a stiff workable material to form pots from. No further processing was done to the clay. I formed small pinch pots from the clay by taking balls of it and pinching out the shape of the pots. Small cracks that formed while shaping were simply mended by wetting and smoothing over. Several pots were made this way. They were then left to dry completely next to the fire until they were completely dry. To fire the pot, it was placed upside down in the hot coals and covered with sticks in a tipi fashion. The wood both acts as fuel and protects the pot from sudden changes in temperatures such as those caused by sudden winds. When the fire was burning well, I increased the temperature of the fire by fanning it with a fan palm frond. The pot glowed red hot amongst the coals and so was fired to a sufficient temperature. After waiting overnight, the pot was retrieved from the ashes and struck with a stick. The pot gave a clear ringing sound indicating it was strong and had no cracks (hollow sounds indicate the opposite). Now I had a small bowl to carry water in. A larger pot was then made from the same clay. This time the walls of the pot were built up using the coil technique where long rolls of clay were rolled and then squashed onto previous layers. The last layer was pinched outwards to form a pot lip. A lid was made for the pot by making a flat disk of clay with a small handle for lifting. When dried the pot was then fired as before but in a larger pit outside the hut. Again, the pot was covered with wood protecting it from sudden breezes that might cool or heat the pot suddenly, possibly causing cracks. The firing went well and the pot sounded strong when struck. The pot was then placed on 3 rocks and a fire lit underneath. It took close to 30 minutes to boil this way with lots of sticks. But it did eventually come to the boil. I then made a stove inside the hut. The fire pit was dug and extended into a trench, sticks laid over the entrance and mud mixed from the excavated dirt was then used to form the walls of the stove over the trench. The stove was about 30 cm internal diameter but came in to about 20 cm. Three raised lumps were made on the top of the stove to hold the pot above. Then the stove was fired. Note that wood can be placed over the entrance of the stove at ground level and lit in a hob firebox like configuration. The flames then get sucked down and then up into the stove. I show this because it’s an easy way to manage the fire without making it too big which might burn the thatch. When the pot is on the stove, it’s easier just to put sticks straight into the top of the stove between its open top and the sides of the pot. If over stacked with wood, wood gas is produced burning in a second fireball above the stove. It’s best just to keep the flames big enough to surround the pot (to reduce fire hazards). The pot was quicker to come to the boil then over a three stone fire. The clay here in the new place is good, it didn’t take me long to make pottery here. Notably this clay doesn’t seem to need grog or temper added to it to prevent it from cracking. I think this is due to tiny specs of mica that weren’t present in the clay from my old area. The clay seems stronger and there also seems to be much more of it everywhere. The pot boiled after a while of tending, in future I’ll probably make thinner walled pots so that they boil quicker. The stove was useful for boiling the pot. It also seems to reduce the amount of smoke in the hut and increase the life of the coals in the base so that the fire could be re stoked at a later time.

Première diffusion : 22 décembre 2017

S2 E3 • A-frame hut

I built an A frame hut as a large work space for projects. First I made a celt hatchet to cut timber for the hut. The axe head was made of amphibolite and the handle was made of a species of wattle. For the hut the floor plan was 4 X 4m. The height of the ridgeline was 2 m above the ground. +A post was planted in the ground to support the ridge pole at the back of the structure and an A frame was put in the front to support the ridgeline. The rafters of the hut were then attached to the ridgepole. Palm fronds were then collected, split and lashed to this frame. The dome hut was disassembled and its thatch was added to the structure. Approximately 1200 fronds were used in total. For the ridgeline, thatch was lifted in place and rested on without lashing it down. Instead, pairs of sticks lashed together were lifted in place sitting over thatch preventing it from blowing away. These are known as “jockeys” as they resemble a rider sitting on a horse. A wall of wattle and daub was built at the back of the structure. Wooden poles were planted into the ground and lawyer cane was woven between them. Soil was dug from around the hut forming drainage trenches while also supplying the mud used to daub the wall. No fibre was added to the daub, just straight mud. Pegs were stuck into the wall to form a convenient rack to hold the stone axe off the ground when not in use. Later, pegs were added to support the fire sticks too. A bed was made by hammering in wooden stakes and lashing timber to the frame. This was covered with palm fibre to act as bedding. Atherton oak nuts were then collected and eaten/stored in a pot. Latter, heavy rain fell testing the huts ability to shed rain. The hut stayed dry while the water flowed off the thatch and into the drainage trenches left over from digging the mud for the wall. The A frame hut is a simple shelter that can be built quickly and simply. It’s basically a large roof built directly on the ground. The shape is strong and should resist strong winds. This hut is the biggest one I’ve built on this channel and could fit both the tiled roof hut and wattle and daub hut inside it with room left over along the sides. It requires no scaffolding or ladders to build. A person can walk right down the centre without ducking while the sides that are too low to stand in are used for storing firewood, tools and other things. A fire lit in the entrance will greatly reduce the number of mosquitoes in the hut though it will get smokey occasionally. To reduce smoke, a small stove could be built to burn the wood more efficiently. A chimney and fireplace could be built also, but would take more time.

Première diffusion : 19 janvier 2018

S2 E4 • Lime

At the old hut site (the new one being temporarily cut off by flooding) I made lime mortar from the shells of rainforest snails by firing them in a kiln, slaking them in water, mixing them into lime putty. Limestone is basically calcium carbonate (CaCO3). The general source of lime is limestone and various other calcareous minerals, though shells, egg shells and coral are other sources of lime (for more information see video on Corporals Corner channel: https://youtu.be/tOhAfaFboNU). When heated above 840 degrees Celsius, the lime decomposes into calcium oxide (CaO) or Quicklime and releases carbon dioxide (CO2). When water is added to the quicklime it becomes calcium hydroxide Ca (OH)2 or lime putty. From here the calcium hydroxide can then be shaped into a form and allowed to set. Carbon dioxide enters the lime putty as it dries causing it to turn back into calcium carbonate. The new calcium carbonate has then set, remaining solid and water resistant. In my local geography, calcareous rocks such as limestone are absent leading to a difficulty in acquiring the feed stock for lime making. However, I was still able to make lime by collecting the shells of large terrestrial snails that are native to the rainforest here. The unoccupied shells of these snails were gathered up and stored at the hut. Fire wood was gathered and packed neatly into the kiln. Importantly, the firewood was stacked on top of the grate rather than underneath it in the firebox as is the normal procedure for firing pottery. Using an ordinary updraft pottery kiln in this configuration allows it to reach much higher temperatures than would be possible during normal use. The wood was lit from above and the fire burned down towards the grate. Alternate layers of shells and wood were added on to this burning fuel bed. After adding the last layer of wood to act as a “lid” to prevent heat loss from above I left the kiln to finish on its own, unsupervised. The whole process took about an hour and a half. When the kiln had cooled down a few hours later, I took out the calcined shells. Not shown in the video was the fact that some shells got so hot, the dirt stuck to them turned into slag and fused to them, possibly with the lime acting a flux lowering its melting point. This extreme heat (+1200 c) should be avoided as the over burnt lime becomes “dead lime”, unable to slake in water. Most shells were still useable though. They were taken out of the kiln and had water added to them. An exothermic reaction then ensued. Heat was produced as the lime quicklime turned into slaked lime. The water heated up creating steam and the shells decomposed into a white paste. The paste was stirred and crushed pottery was added to it as an aggregate (sand is normally used for this, I just had a lot of old pot sherds lying about to dispose of). This lime mortar mixture was then formed into a block shape and left to dry. It took about a week and a half to set as we have had extremely humid, wet weather. The block was observed to have set demonstrating its properties. What I created is actually lime mortar, typically used for mortaring bricks and tiles together. It’s basically the ‘Glue’ that holds together the building blocks of masonry structures. From my research 20 kg of lime mortar is used on a 1 m square section of brick wall. 5 kg of lime to 15 kg of aggregate (sand, grog etc.) per a 1 m square section of bricks. The shells, though large, are not terribly abundant. A method for finding shells efficiently needs to be made before considering making lime mortar in this fashion. From my experience sand bars in a creek sometimes accumulate snail shells from higher up in the mountains. In these spots, water velocity decreases and shells in the water tend to drop out of the water column. Additionally lime may be partially replaced with ordinary wood ash in mortar without a corresponding decrease in strength. To conclude, making lime in a land without limestone is possible but can be problematic when trying to do so on a large scale.

Première diffusion : 6 mars 2018

S2 E5 • Round hut

I built a round hut using palm thatch and mud walls to replace the damaged A-frame hut built a few months ago. The A frame hut was damaged due to torrential rain and poor design elements considering the wet conditions. The thatch had rotted in the part of the roof that gets shade. Moth larvae and mold grew and consumed the thatch in these places. The hut also tilted forward due to the back post being hammered in only 25 cm into the ground. So on returning to the property (it was cut off by flooded bridge) I began work on a new hut. The new hut was positioned further into the open clearing to get more sunlight. A 3 meter diameter circle was scribed and 12 wooden posts were hammered into the ground, each 50 cm deep for a sturdier structure. Lintels were then tied to the top of the posts joining the posts together. A tripod ladder was made from poles lashed together at the top and a platform lashed to its frame. The roof poles were then attached to the top of the lintels and lashed together at the top to form a conical roof frame, 3 meters at the highest point. Loya cane was then tied on the eaves to act as support for the ends of the palm thatch. 700 palm fronds were then cut split and thatched onto the roof. The tripod ladder was used to climb up and thatch the roof from the inside. A cap was then made to put on the very top of the cone when the roof was almost finished. A drainage moat was dug around the hut and the excavated soil was placed on the hut floor to raise its level above the damp ground. A deluge tested the hut’s water shedding abilities. Torrential rain fell while a fire was kept going inside the dry hut. The drainage moat flowed like a stream during the heavy rain event. Loya cane was then harvested and woven between the posts. This formed a low wall. It was then daubed with mud inside and out. The clay from this was taken from the drainage moat. Rain falling into the moat meant that water didn’t need to be collected from the stream to mix the mud. This is another benefit of the drainage moat. The low wall allows light and air into the hut. With a fire going in the central pit, mosquitoes are kept at bay. The central fire pit produces smoke and heat that will hopefully prevent moths laying eggs in the roof (the caterpillars of which eat thatch) and will prevent mold from growing. The hut will be used as an undercover work space for future projects.

Première diffusion : 20 avril 2018

S2 E6 • Blower and charcoal

I made a blower and some charcoal at the new area in order to create higher temperatures in for advancing my material technology. I took Fan palm leaves and fashioned them into an impellor (about 25 cm in diameter) held in a split stick as a rotor. I then built a housing from clay (slightly more than 25 cm diameter with inlet and outlet openings about 8cm in diameter) and assembled the blower. I opted not to make a bow or cord mechanism as I’ve done before due to the complexity and lower portability of such a device. The lighter impellor material (leaf instead of the previous bark) made it easier to spin by hand anyway as it has a lower momentum. Each stroke of the spindle with the hand produces 4 rotations, so about 2 strokes per second gives 480 rpm. The blower increases the heat of a fire when blowing into it and I would guess it’s more effective than a blow pipe and lungs but don’t how it would compare to a primitive pot or bag bellows for air supply. A small furnace was made and then fired with wood fuel. The wood was wet but managed to fuse and partially met sand in the furnace. To get better performance, I made charcoal from the poor quality wood. I made a reusable charcoal retort to make it. This was different from the previous reusable mound I built as it consisted of a mud cylinder with air holes around the base. To use, it was stacked with wood and the top was covered with mud as opposed to the previous design which had a side door. The fire was lit from the top as usual and when the fire reached the air entries at the base (after an hour or two) the holes were sealed and the mound left to cool. The top was the broken open the next day and the charcoal removed. Another batch was made using significantly less effort as the main structure of the mound did not need to be rebuilt each time, only the top. Iron bacteria was again used to test the furnace. Charcoal and ore was placed in the furnace and the blower utilised. After an hour of operation the furnace was left to cool. The next day the furnace was opened and only slag was found with no metallic iron this time. I think increasing the ratio of charcoal to ore might increase the temperature so that the slag flows better. Further experiments will be needed before I get used to the new materials here. The new area I’m in is significantly wetter than the old area and this has affected the order in which I create my pyro technology. The old spot was a dry eucalypt forest with an abundant source of energy dense fire wood. As a result, I developed kilns early on, powered with wood fuel and a natural draft, before developing charcoal fuelled forced air furnaces. In contrast, the new area is a wet tropical rainforest, where wood rots nearly as soon as it falls off the tree in the damp conditions. Wood is also more difficult to collect here because of hordes of mosquitoes (away from the fire) and unpleasant, spiky plants. Because of this I developed a forge blower first as it allows higher temperatures from a lower quantity and quality of fuel. This poor quality wood can further be improved by converting it to charcoal first. In future, it may be necessary to cut fire wood green and dry it as opposed to picking it up off the ground dead as was preferable in the Eucalyptus forest I came from. The blower is also handy for stoking a tired campfire back into flames, I simply scrape the coals into a small mound around the nose of the tuyere and spin the impellor. I use the blower each day I’m at the hut for this purpose to save blowing on hot coals each time I need a fire for something.

Première diffusion : 18 mai 2018

S2 E7 • Yam, cultivate and cook

I planted a yam in a large basket like enclosure and then 6 months later harvested, cooked and ate it. My previous attempts at growing yams were stymied by wild pigs and scrub turkeys. On learning that yams are in the area, these animals will seek out any tubers planted and eat them. So my solution was to build a large basket like enclosure to protect the growing vine. 13 wooden stakes were hammered into the ground (an odd number being important in any weaving project) and lawyer cane harvested from the forest was woven between these uprights. The basket was about 1 m in diameter and about 75 cm high. A large yam, partially eaten by wallabies from a location further down the creek, was dug up and carried to the site. A small pit was dug in the enclosure and the yam simply placed in it. The enclosure was then back filled with dead leaves for fertiliser. As time progressed the vine grew above the basket and a long pole attached to it so it could climb into the canopy making full use of the sun. After 6 months and no maintenance, weeding or watering the yam had grown into two large tubers whereas the original yam had rotted away leaving a thin husk. The new tubers were dug up using a digging stick. As carful as I was, the yams sill broke off with more tuber still under ground. This portion will probably strike next season anyway. In the canopy, the vine also produced smaller tubbers called “bulbils”. These were collected in a pot to be used as seed yams for a larger garden I’m planning. You can eat bulbils as well but the larger yam is generally eaten instead due to its larger size. To cook the yam a fire pit was dug about 30 cm in diameter and about 20 cm deep. Wood was piled above the pit and set alight. The hot coals then fell into the pit where rocks where added to retain heat. The coals were scraped aside and the large tuber was broken up and thrown on top. The coals were raked back over it and a fire started on top. This cooked for 30 minutes before being pulled out of the coals. The outer layer of the yam was charred black and burning but the inside was soft and well cooked. The yam was eaten while steaming hot and tasted similar to a potato but with a crunchier texture near the outside much like bread crust. Although bland, yams provide a good deal of carbohydrates and are eaten as a staple in certain cultures. The remaining large yam tuber was tied up in a tree where rats could not eat it (hopefully). This form of farming is a good way to get around the conventional farming practice of clearing trees to make fields. Instead the yam vine uses the trees as scaffolding to climb on, allowing it to reach the light in the forest canopy. The basket enclosure worked well to keep forest creatures from eating the investment. It also formed a good in-situ compost heap to nourish the yam as it grew. In future, I’d add sand to the mix as yams tend to do well in sandy soil and I expect it would be easier to dig up. Yams do well in dry conditions but will yield more if well-watered so digging a water retaining pit might help. Despite the large size of the yams I grew relative to ordinary potatoes, much larger ones are possible and are indeed routinely grown. The largest one from my research was 275 kg, grown in India. Yams have 116 calories per 100 grams compared to potatoes at only 93. They store well in the dry season as they are adapted to having a dormant period during these conditions. They are versatile in that they can be cooked into chips, roasted, boiled, mashed and made into a type of dough called “fu fu” typically eaten with stews.

Première diffusion : 15 juin 2018

S2 E8 • Wood Ash Cement

I developed an experimental cement from made only from re-fired wood ash as its cementitious material. It was mixed with crushed terracotta as an aggregate and formed into a cube. The cement set hard after 3 days and did not dissolve in water after this period. Process: First I burnt bark and leaves in a kiln at high temperatures to produce well burnt, mostly white wood ash. The ash was then mixed into water and stirred well. The excess water was poured off and the resulting paste was made into pellets and allowed to dry. A pellet was then re-heated in the forge until it glowed about orange hot. This was then taken out, cooled and dropped in a pot of water. The pellet dissolved and boiled due to a chemical reaction with the water. The paste was stirred and crushed terracotta (old tiles from previous projects) was added and mixed to form a mouldable mortar. This was formed into a cube and allowed to set for three days (in the video, a cube made exactly the same way 3 days previously was used due to time constraints). The resultant cube was strong and made a slight ringing sound when tapped with a finger nail. It was placed in water for 24 hours to simulate a very heavy rain event and did not dissolve or release residues into the water. My current theory: The main component of wood ash consists of calcium in some form (e.g. calcium carbonate, calcium oxide). This can be up to 45% from my research. Calcium is in higher concentration in the bark and leaves of a tree. When the ash is mixed with water, the soluble component of wood ash (10% pot ash) dissolves into the water. But seeing that it does nothing for the cementing process, it is drained off leaving the insoluble calcium (and other components) in the paste. Doing this probably raises the relative percentage of calcium in the paste to about 50% or more. Most of the other 50 % consists of silica and alumina which are pozzolans, materials that chemically react with calcium hydroxide to increase the durability of the cement product. The paste was then made into a pellet and fired again to high temperature to convert all the calcium compounds to calcium oxide. It also reduces any charcoal in the pellet to ash if it hadn’t already been burnt the first time. This step seemed important as un-fired ash pellets only partially hardened and would fall apart in water, though retaining a weak undissolved 5mm thick crust. I can only surmise that re-firing the ash just gave a greater conversion of the calcium components to calcium oxide. The pellet is slaked in water converting the calcium oxide to calcium hydroxide. This cement was mixed with crushed terracotta which may also help in some way that I’m not aware of as I only did this one experiment and did not test other aggregates yet (e.g. sand, gravel etc.). Terracotta is porous and might hold together better than other materials. The mixture is allowed to set in air where carbon dioxide reacts with calcium hydroxide to form calcium carbonate cementing the aggregate together. After this, the cement will not dissolve in water. Use: I think this material might have a potential use as a mortar holding rocks or bricks together in wet environments where limestone or snail shells are unavailable for making cement. Wood ash is a pretty ubiquitous material to most natural environments inhabited by people using biomass fuels. Wood ash cement turns a waste product into a valuable building material. From my research, wood ash is already being used as a partial replacement for cement in the building industry without decreases in strength of the final product. But I’ve only just started experimenting with it and don’t know its full capabilities and limitations. Calcium content of wood ash differs depending on the species of tree, the part of the tree burnt and the soil it’s grown on. Cautious experimentation is still required before committing to a hut built from this material.

Première diffusion : 17 juillet 2018

S2 E9 • Iron Prills

I smelted iron bacteria in a short furnace and produced a small quantity of iron prills (small iron spheres). In my ongoing quest to reach the iron age, further experiments were conducted concerning furnace design and the treatment of ore. I began by making a very short furnace. A pit 25 cm wide and 25 cm deep was dug and the tuyere of the forge blower placed in a 15 degree downward angle into the pit. Onto this, a furnace stack made of mud and grass was built 25 cm above ground level. The furnace was fired at various stages to help dry it. It took less than a day to build. Eucalyptus wood was collected dead off the ground and stacked into a re-useable charcoal mound I had made previously. The top was sealed with mud and the mound lit. It took about 2 hours 30 minutes for fire to reach the air entries, at which time the holes were sealed and the top closed with mud. Iron bacteria from the creek was gathered and brought to the smelting hut for processing. Charcoal was ground into a powder and mixed with the ore and water in the proportions of 1:1 char to ore by volume. This mixture was formed into 59 pellets 2.5 cm in diameter and then dried on top of the furnace. To make the smelt, a wood fire was made in the furnace and allowed to burn for about an hour by natural draft and blowing. When the wood burnt down to the tuyere the furnace was filled with charcoal and 10 pellets were added to the top and the blower was engaged. Three handfuls of charcoal and 10 pellets were added at about 7 minute intervals totaling about 42 minutes. Charcoal was then continuously added after the last charge until the basket was empty. It took a total of about 3 hours working the blower until the operation ended. The mass of slag and iron prills was prized out of the furnace using a log and wooden tongs. It was hammered flat while hot but no large bloom was made. Instead many small iron prills were found. These mostly seemed to be cast iron. So far this is the largest amount of iron I've made in the wild and it used less charcoal than previous attempts, so I consider it a success of sorts. The ore must be mixed with carbon to ensure the correct reduction chemistry normally provided by carbon monoxide in a taller bloomery furnace. The fact that cast iron was produced suggests that next time less charcoal powder be added to the ore pellets or perhaps none at all considering that dead iron bacteria may also contribute some carbon to the ore. Alternatively, cast iron can be re-melted in a "finery" furnace, a small highly oxidizing furnace, to remove excess carbon, producing steel or iron. Alternatively cast iron can be converted into malleable cast iron by heating it in an enclosed container at 800-1000 c for long periods. Further experiments will be conducted.

Première diffusion : 17 août 2018

S2 E10 • Pit and Chimney Furnace

While I’m working on other projects I’ll put up this video of an experimental furnace I built that operates by natural draft and uses charcoal as a fuel. The furnace burns the fuel on a grate for maximum area of air entry. The chimney attached to the furnace is 2 m tall above ground level. The pit is 25 cm cubed and extends below ground level. The whole structure took about 2 weeks to build. A brick of iron oxide (from iron bacteria) mixed with charcoal powder was made and placed in the furnace sitting on a grate about 12.5 cm tall. The furnace was lit with wood and fired. Charcoal was added after this point and a high temperature was reached. The ore brick melted and produced some tiny beads of cast iron. In contrast to the other furnace I made in the previous video, this one produced less iron while consuming the same amount of charcoal. I’d actually built this furnace before the previous video in an attempt to reduce labour by having a tall draft chimney replace the work and complexity involved with using a blower. I’ll keep experimenting with natural draft furnaces, the principle is sound but the method of introducing the ore (batches of ore on a grate instead of continuous addition of ore pellets) is probably inefficient or could be improved on.

Première diffusion : 16 décembre 2018

S2 E11 • Stone Yam Planters

With the wet season here, it's time to plant this years crop of yams. The previous yam garden, a large basket type enclosure, worked well in discouraging predators from eating the growing tubers. But with time the cane enclosure rots. So I switched to a method of protecting yams by planting the seed yams under a pile of rocks. Early tests prove that this method protects them from being eaten. The rocks are too heavy for scrub turkeys to lift and wild pigs seem not to associate the pile of rocks with food. So the next step was to make a garden consisting of individual mounds fortified with neat stonework. This was done by building layers of stone circles around the mound while adding soil with each layer. A yam bulb was planted in each mound during this process. A wooden stake was placed in each mound for the yam vine to grow up and horizontal rafters were tied to the top of these stakes to give the vines something to grow across. By the end of the project the yams had started growing with some coiling around the stakes.

Première diffusion : 18 janvier 2019

S2 E12 • Grass thatch, Mud hut

With the wet season at it's peak, a shelter was needed to keep tools and materials dry as well as providing a dry work-space for future projects. So after some procrastination, I decided on a low roof design. A 2.5 m by 2.5 m hut with a ridge 2 m above the ground and side walls 75 cm high. Upright posts were put in at about 60 cm intervals along the 3 walls. The front was left open as this is more of an open workshop than a dwelling. Grass was collected from high up in the hill as it will not grow in the darker, lowland forest. Carrying the thatch to the hut was the most labor intensive part taking approximately 36 hours over the course of more than a week. The walls were then coated in soft, grey mud from a nearby clearing. The floor was coated in the same material. A large amount of rain fell due to a nearby tropical cyclone passing to the north. Despite this there were only a few leaks (mainly on the ridge line) that were subsequently patched with more grass. A fire was then lit with fire-sticks despite the damp conditions. This was done to help dry the mud walls and floor. The end of the video shows the yam mounds behind the hut doing well from of the torrential rain. The shelter will suffice for the remaining two months of rain that is expected to fall.

Première diffusion : 22 mars 2019

S2 E13 • Fired Clay Bricks

I made some fired clay bricks as an experiment to see if I could make a permanent, waterproof, building material. A brick mold was fashioned from clay and then fired in existing kiln. This was then used to make bricks formed from clay from the creek bank. These bricks were then stored in the hut I built last episode to dry. Using half the hut I could fit 40 bricks. These, when semi dry, were then stacked around the fire to dry out. A small kiln was then assembled from un-fired bricks and used to fire 4 bricks as an experiment. It was about 50 cm tall and 25 cm square in cross section. The fired clay bricks were water resistant, they didn't dissolve when submerged in water. I will use these bricks to make a larger kiln and hopefully larger huts later on. I estimate that a kiln with a 50 cm cube ware chamber could hold 40 bricks without being so cramped the flames can't get through. The good thing about using bricks to make kilns is that they can be constructed quickly without waiting for the layers to dry, they only crack along the joints between bricks while remaining structurally stable, they can be disassembled and built elsewhere or they can be reconfigured/enlarged to make different types of kilns. Repairs are also possible too.

Première diffusion : 26 avril 2019

S2 E14 • Polynesian Arrowroot Flour

I gathered polynesian arrowroot, grated it, extracted and dried the starch and cooked it into gelatinous, pancake shaped food that tasted like rice noodles. Polynesian arrow root is a plant in the same family as yams but with a different growth habit. It has a single, branching leaf and a single tuber below ground. They were brought to Australia about 7000 years ago as one of the "canoe" plants carried by Polynesian seafarers and grow wild in the hills near my hut to this day. The tubers are rich in starch but have a bitter compound that needs to be leached out with water to be made edible. This same compound is traditionally a medicine in small quantities for treating a range of illnesses from gastrointestinal upset to snake bite. I dug up the tubers which took about 3 minutes to do per plant, yielding one golf ball sized tuber each. These were then washed and grated into a pot using a roof tile. The resulting mash was mixed with water and allowed to settle. The white milky water was then scooped into a second pot and the starch was allowed to settle. The water was then poured off and more starch water was tipped in. At this stage the starch was still bitter, so it was mixed with water, allowed to settle and the clear water above was poured off several times removing this bitterness. When it tasted good, the paste was put onto a tile to dry over a fire. Some of it cooked and became small rubbery pieces of starch. The dry flour was stored in a pot. Some of this was then mixed into a paste and cooked on a tile like a pancake. It turned clear when cooked and has a rubbery texture. It tasted just like a rice noodle which is unsurprising considering the ingredients are nearly the same. Starch is the largest carbohydrate in the human diet. Polynesian arrowroot starch contains 346 calories per 100 g (wheat contains 329) and so the discovery of this staple food is fairly significant. It can be stored indefinitely if kept dry and away from weevils or can be stored as live tubers for six months (then they begin to sprout and should be planted). The live tubers bitterness means animals will not eat them which is good for storage. I may cultivate some in a small plot in the hills near where I dug them up. They are numerous in the wild but may produce more if the soil is tilled.

Première diffusion : 31 mai 2019

S2 E15 • Crossdraft kiln

I built a cross draft kiln and fired a pot in it to test ideas about how cross draft kilns operate. A cross draft kiln is one in which the flames travel from the firebox and across a horizontal wear chamber before traveling vertically up a chimney and out of the kiln. Unlike an updraft kiln there is no perforated floor that the pottery sits on. Instead the pot sits on the floor of the wearchamber as the flames pass around it. Taking soil from a previous kiln and mixing it into mud, I formed the kiln so it was less than a meter long. It was 25 cm wide and tall inside the tunnel formed by the kiln though a slight curve was added to the tops of the side walls. The walls were covered with sticks and a roof of mud was put in place onto this. A chimney about 25 cm wide and 65 cm in total height was made at the end of the kiln to draw flames through the kiln due to natural draft. 5 grate bars made of clay were installed in the firebox to make combustion more efficient. A side door was cut into the kiln to access the ware chamber (25 x 25 cm). Clay was taken from the creek bank and mixed with previous crushed pottery as grog. It was formed into a pot with a pouring spout. This was dried and then placed into the kiln. The kiln was fired with the flames acting as planned and the pot was fired in a relatively short 1 hour and 20 minutes. It would have been a shorter firing time had the kiln not still been wet. The pot was tested with water and held it satisfactorily. Cross draft kilns are an apparent improvement on updrafts with the reasoning being that more efficiently retain heat as the hot gasses don't immediately exit the kiln leaving the colder gasses inside. Hot spots are less likely to develop giving a more uniform firing of the pottery. Cross draft kilns developed early in Asia, evolving from the practice of excating tunnels into the side of hills to fire pottery. It's unknown whether the European cross drafts were adopted from the east or were the result of the gradual extension of the firing arch outwards from the conventional updrafts. My personal experience is that this type of kiln fires quickly and evenly though I need to experiment more to understand the positive and negative aspects more fully. About Primitive Technology: Primitive technology is a hobby where you build things in the wild completely from scratch using no modern tools or materials. These are the strict rules: If you want a fire, use a fire stick - An axe, pick up a stone and shape it - A hut, build one from trees, mud, rocks etc. The challenge is seeing how far you can go without utilizing modern technology. I do not live in the wild, but enjoy building shelter, tools, and more, only utilizing natural materials. To find specific videos, visit my playlist tab for building videos focused on pyrotechnology, shelter, weapons, food & agriculture, tools & machines, and weaving & fiber.

Première diffusion : 12 juillet 2019

S2 E16 • Hut burned down, built new one

My hut burned down after I left a fire untended in it. I needed a new one quickly. Fortunately I had already cleared a new spot earlier in the wet season for such a purpose. I constructed the new hut from wood and palm thatch. It was 3 x 3m in floor plan and a total of 3m high with 1.5m high side walls. 4 posts were put into the ground and a pyramidal roof was built on top of this. The frame was then thatched with palm fronds (which are less flammable than grass thatch but don't tend to last as long in wet weather). After finishing the hut I collected the possessions from the last hut and moved them into the new one. Yams from the garden were dug up but there weren't many due to the soil being compacted and low in organic matter. A yam was cooked by wrapping it in clay and baking it in the hot coals for 30 minutes. Now I have a larger hut where I can continue to make projects despite the minor set back that has just occurred.

Première diffusion : 9 août 2019

S2 E17 • Adobe wall (dry stacked)

I made clay bricks, air dried them and then built a dry stacked (no mortar) wall from those bricks. Brick making is a time consuming process. To amass enough bricks for a large scale firing will take a long time to do. In the previous hut (that burnt down) bricks were stored inside the hut out of the rain to dry before firing. This took up considerable space within the hut. So with this hut, bricks were stored under the eves of the hut forming a temporary wall around the work space. Clay was taken from a pit and carried to the hut site. The clay was mixed with water in a pit. The ceramic brick mold (made of fired clay in a previous video) was soaked in water and wood ash to make it slippery so that the clay would slide out easily. Bricks were then formed on the floor of half the hut. When the bricks had dried enough they were then stacked under the eaves to form a growing wall. I'll continue making clay bricks and when an opportunity rises, I will take them out and fire them, upgrading them from adobe bricks to fired clay bricks. These will in theory be used in a permanent hut constructed from bricks and mortar.

Première diffusion : 5 septembre 2019

S2 E18 • 4 years of primitive technology

Première diffusion : 25 octobre 2019

S2 E19 • Brick Firing Kiln

Première diffusion : 29 novembre 2019

S2 E20 • Pot Made of Wood Ash - New Clay Alternative

Première diffusion : 13 décembre 2019