#Giestas #video on #manufacturing cork-filled-agar-soled sandals using a corrugated-sole mold made from corrugated cardboard. The cork came from diced wine corks ground in a coffee grinder and sifted with a kitchen sifter to separate into cut, coarse, medium, and fine grades. 3 parts glycerin plasticizes 4 parts agar. A tiny amount of charcoal, ground in a mortar, is an additional filler for color. #Casting the heavily filled gloop in the cardboard mold looks fiddly. Used-tea-leaf tannin colors the alginate “leather” straps: 1 part alginate, 2 parts glycerin, 30 parts brown water, apparently by volume. The leather is crosslinked with a spray of 1 part CaCl₂ in 10 parts water. A box cutter tracing a masking-tape strap model tested over a sock cuts out the straps, which fit between the bottom sole and a lighter “midsole” made with 3 parts agar to 2 parts glycerin filled with coarser cork. Then the upper sole (insole) is softer, 1 part agar to 1 part glycerin filled with fine cork pigmented with mortar-ground tea leaves. Baked 1 hour at 100° with the fan on. #materials
on 02025-10-18#Giestas #video on #manufacturing an egg-shell-filled bioplastic bowl: 100mℓ water, 10mℓ glycerin, 15g agar, 2 drops clove oil, 100g eggshell (membrane removed, soapy-water-cleaned, oven sterilized, ground with mortar and pestle). So I guess the product is about 80% eggshell. He uses two glass bowls as the mold for #casting the thicker bowl. #materials
on 02025-10-18#video by #Giestas on #manufacturing a cup from used coffee grounds by binding them with agar and honey, melted in a double boiler before stirring in the grounds, then pressing the soft mass into a three-part mold made with #3D-printing, about 1cm thick. It suffers cracking damage from wetting/drying cycles. Oil of wintergreen to prevent mold, and he makes a planting pot. Relative quantities of honey, agar, oil of wintergreen, and coffee grounds are not disclosed. #materials
on 02025-10-18#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