#Nighthawk #video about #electrolysis for, e.g., electrowinning metal #materials. First big science error is at 8'08": “Actually everything that dissolves in water splits into ions when it does so.” Nope. He claims to be making #DIY ion-selective membranes using Robert Rowow’s recipe, using off-the-shelf PVC cement and ion-exchange resin beads from water softeners, reinforced with fiberglass cloth, but I’m not clear how he validates them. He recommends using a hot glue gun to hold the membranes in place in his water buckets with EVA. He also turns carbon welding blankets into conductive carbon felt electrodes. He reports 250mA at 1.2 volts from his semipermeable-membrane plastic-bucket Fe⁺⁺/Fe⁺⁺⁺ flow battery with roughly A5-paper-sized carbon-fiber electrodes. Also he makes hydrogen sealed into the cathode compartment of a cell with one of these semipermeable membranes.
on 02026-06-03#Nighthawk #video on 50%-air to 75%-air aerated #concrete with “kitchen ingredients”; he likes 60% best. Specifically, he stabilizes the foam with pre-hydrated xanthan gum to keep it from collapsing while you’re mixing the cement. Dawn Ultra dish detergent (one part to 16 parts water) is his surfactant. Initially wetting the xanthan gum with “rubbing alcohol” (presumably isopropanol) helps a lot with wetting it; glycerin is apparently unnecessary. He thinks that this works because the xanthan gum slows the cement’s absorption of water.
on 02025-12-19#Nighthawk #video #toread about bioplastics #materials from potato or cassava starch, and spectrally selective cooling materials. 5 mℓ of honey can plasticize 30 mℓ of gelatin dissolved in 560mℓ of water and then dried in a food dehydrator in a silicone mold. Recommends a YT channel about bioplastics, @Giestas, a high-school teacher in Lisbon. Second recipe: 12 parts water, 3 parts cassava (or other) starch, 1 part vinegar, 1 part glycerin (as a plasticizer), optionally reinforced with cotton gauze. He claims you can separate potato starch by simple decantation. As usual, he butchers the science, claiming that freeze-dried starch gel is an aerogel. He claims that these starch gel films have high infrared emissivity, even though they look transparent to visible light. Third recipe, alginate — which, astoundingly, he mentions can be de-gelled by chelating the calcium with sodium citrate! And a suspension of calcium carbonate in sodium alginate can be gelled with vinegar, because that solubilizes the calcium! Or by using glucono-delta-lactone, tofu coagulant, to release acid over 10' to 20': 100mℓ water, 10g (sodium?) alginate, 2g CaCO₃, 2g GDL. Fourth recipe, agar, which dries into crystal-clear films that can resist water for a few days. 20g agar (!!) in only 100mℓ of hot water, 2mℓ dish detergent, whip with blender. #Giestas offers: “3 tbps agar, 2.5g citric acid, 3tbsp gli[cerin?], 1tsp baking soda” to produce foam; and “60mℓ agar, 30mℓ MGL [or “mel”: honey?], 60mℓ gli[cerin?], 180mℓ water, 5mℓ deter[gent?]”.
on 02025-10-17#video by #Nighthawk on #tadelakt fabric by dunking soapy fabric in alum water to form an insoluble, hydrophobic polyvalent soap, which can nevertheless be wetted by a forceful spray of water. Also he tries dissolving paraffin in naphtha.
on 02025-08-12#Nighthawk #video on waterproofing and stiffening #cardboard by brushing on 500mℓ isopropanol, 125g shellac, 15g beeswax (emulsified), 2g metal stearate (slowly stirred on low heat on an electric burner outdoors). Also demonstrates a totally game changing edge-sealing technique where you cut halfway through the cardboard to isolate one side, then fold it over. Also you can stiffen the surface with wheat paste. And maybe pasting on extra layers of newspaper or paper bags. Also, you can edge-splice panels with the same cut-halfway-through technique and then pasting the sides thus isolated. He also touts his waterproofing mix as a way to make fabric waterproof, showing some very impressive demo video. His second waterproofing recipe is 100g EVA hot glue diluted with 25g paraffin wax and 20mℓ mineral oil. He also demonstrates homemade lampblack with a vegetable oil candle under an aluminum tray for UV protection, but thinks calcium stearate might work well enough for UV protection, which is his reason for including it; he recommends reacting soluble sodium stearate (made from stearic acid and lye) in water with sulfate of aluminum, zinc, or magnesium, or muriate of lime, to form the insoluble metal stearate. Doesn’t contain his usual total mangling of the science. #DIY #bootstrapping #materials
on 02025-06-14#video on #Nighthawk trying to form stable colloid #phase-change #energy-storage #materials with sodium lignosulfonate #toread
on 02025-03-26#Nighthawk #video about DIY salt-based thermal phase-change #energy-storage. He’s using food-grade sodium sulfate in what looks like a fertilizer bag but is probably actually being sold as a phase-change material by Duda Energy, then mixing it with sodium chloride to approach the eutectic of the ternary system with water; he says 1.2ℓ water, 240mℓ of (presumably hydrated) sodium sulfate, and 60mℓ of sodium chloride melts at 18°. He says actually it has “multiple melting points” so it probably melts incongruently, giving rise to phase separation through repeated freezing; he suggests that gelling it with carboxymethylcellulose or xanthan gum (his choice) will solve that problem. He suggests sealing it in reusable silicone sandwich bags for use, which you can fit into the pockets of an ice vest. He seems to have measured it supercooling to 9°, then heating back up to 18° when it suddenly freezes, and then a second phase transition at -8°. He made a PCM blanket by soaking a towel in the gel and rolling it up inside a garbage bag, which seems like it would be a good approach to preventing leaks. He heat-sealed the edge of the garbage bag with a butane hand torch. #energy
on 02024-06-23#Nighthawk #video about waterproofing fabric #materials making oilcloth by ironing cubes of paraffin wax plasticized with mineral oil (paraffin oil, vaseline, ideally about 500mℓ per 2kg of wax) into the fabric. This seems dramatically inferior to the naphtha-thinned silicone recipe he showed previously. Contains some of the usual backwards science of Nighthawk videos; here he claims that the thermal coefficient of expansion of steel is greater than that of paraffin wax, for example, and that naphtha and gasoline are carcinogenic. For his jacket he ended up applying it as a paste wax, like to floors, but melting it with a heat gun instead of kerosene. Unrelatedly, he also demonstrates tying a slipknot (a taut-line hitch) around an acorn wrapped in the corner of his tarp in place of a tiedown grommet. Commenters advise that the wax needs to be reapplied every year; that you can filter lubricating oil out of camp fuel with nonwoven polypropylene to get naphtha; that the Hartford Circus Fire was caused by waxed fabric; and that adding about 6% by mass wood ash to the wax improves durability.
on 02024-05-03#Nighthawk making opals from tetraethyl orthosilicate in ethanol with an ammonia catalyst for “free air conditioning”? Really he means wavelength-selective coatings, but he’s confused about the physics. Gorgeous though. #cooling #video
on 02024-04-03#Nighthawk 6 uses for a 90% medical oxygen concentrator, mostly fireworks like senko hanabi, but also using steel brake lines for poor thermic lances and an oxypropane torch, and finally a macaroni rocket/thermic lance. #hoarding #bootstrapping
on 02024-04-03#Nighthawk fireproof expanding graphite #video #toread
on 02024-04-03#Nighthawk DIY solar thermal panels #bootstrapping #energy #video #toread
on 02024-04-03#Nighthawk solar-powered noodles in #flight (#flying?) Mentions Bovine Aerospace’s painter’s-plastic balloon (plástico para pintores, 8μm), which he throws a handful of fine charcoal powder into to get sunlight absorption. Due to not having a giant sealing machine he lays a board across some sawhorses, masking-tapes the plastic to it, and tried sealing it with a clothes iron! Which didn’t work, so he used adhesives, specifically doublestick tape from a craft dispenser. He suggests soot from a fatwood fire might be a better alternative to the charcoal powder. He incorrectly states that water vapor is heavier than air. #video
on 02024-04-03#Nighthawk #thermoacoustics introduction. Cringe-inducing scientific errors as usual; first forehead slap is at about 2:40 into the 18-minute #video. More cringe-inducing errors at 3:55. And, as usual, he doesn’t measure any results such as frequency, amplitude, voltage, or current. Still, he deserves a lot of credit for providing an easy-to-follow tutorial for building a basic thermoacoustic Stirling engine.
on 02024-04-03