#HTME #video on making glass #materials #toread
on 02024-05-01#HTME #video on #bootstrapping rubber #materials from wildflowers, specifically native Minnesota goldenrod. Dried, pulverized in a blender, Soxhlet (?) reflux extraction of unwanted compounds with acetone, then solvent extraction of polyisoprene in toluene. For scaling up, improvised a reflux apparatus out of paint cans, glass tubes, and silicone caulk. Got about 3% of the mass of the dried leaves as rubber goo. Then they vulcanized the raw rubber with sulfur in a toaster oven.
on 02024-05-01#HTME #video on the lead chamber #materials process
on 02024-05-01#HTME #bootstrapping Roman concrete #materials #video; he’s using pumice from the Black Rock Desert volcanic field and pumicite (?) from a mine in California for his pozzolan. He clearly doesn’t know how to make concrete; he’s using smooth river rocks and no sand for his aggregate. Although he does use sand in his lime mortar, his cob, and presumably his modern concrete mix! Also somehow his fired clay bricks were only barely stronger in compression than his cob bricks.
on 02024-04-03#HTME #bootstrapping H₂SO₄. There’s a natural source in Yellowstone which he didn’t use; instead he used sulfur collected from an old sulfur mine in Death Valley which exploded in 01953. He planted red cabbage in raised beds earlier to make anthocyanin as an indicator (but also used commercially made four-dye pH test strips). He tried dry distillation of blue vitriol and green vitriol to get H₂SO₃ (pH 5–6) and then waits (the dry distillation took weeks). For the dry distillation he cheated by making a still out of steel pipe, because this was shortly after the workshop fire. Then he boiled it down to get a pH of 2. But even at a pH of 0.5, industrially produced H₂SO₄ doesn’t dissolve chicken wings, though it does at pH -1.27. Heating pyrite in water to oxidize it reached a pH of 3 after several years. #materials #video
on 02024-04-03#HTME on #bootstrapping batteries and generators, with reference to Dr. Stone. He doesn’t know about current or that the homopolar generator he built can supply a massive current. #video
on 02024-04-03#HTME on #bootstrapping #hardware. #video
on 02024-04-03