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Originally Posted by ghrocketman
Blackshire ALWAYS provides a plethora of good information in his posts.
Always appreciated !
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Thank you, GH--you've also lifted my spirits at a time when it helps! As well (if memory serves):
You had mentioned rockoons as scale model subjects recently (Luis Eduardo Pacheco's "StratoCat" website covers rockoons and other Skyhook-type stratospheric balloons and missions:
http://stratocat.com.ar/indexe.html ), and I found a couple of eclectic books about balloons--including the plastic film Skyhook-type ones--that show how to properly shape the gores to get the right scale "teardrop bubble" (at launch) and "giant onion" (at maximum altitude) envelope shape, including for "natural shape" balloons (which some of the biggest Skyhooks were and are).
Natural shape balloons have flat, or mostly-flat, tops. They're often--if not always--used for lifting heavy payloads, and they only have envelope stresses in the vertical direction (or nearly only in that direction, to minimize stresses on the plastic film); the vertical gore seam seals, which double as load tapes, take up the load, and:
Model Skyhook balloons are easy to make out of the thin polyethylene plastic film dry-cleaning clothes bags, which are available by the box, including on Ebay (they're also called "Garment Bags" or "Garment Covers" [see:
https://www.ebay.com/sch/i.html?_fr...g+bags&_sacat=0 ^and^
https://www.ebay.com/sch/i.html?_fr...+bags&_osacat=0 ]; it's the same plastic that full-scale Skyhooks are made of, except that they're often of even thinner-gauge plastic! The gores can be joined using narrow cellophane or Scotch/3M tape (craft stores sell narrow-width rolls of it). I'll post all of this material separately, on the Scale and Sport Scale sub-forum.