Sail Materials and Sail Aspects for Hang Gliders
This topic invites the study and discussion of materials for dressing hang glider frames in order to effect gliding and soaring in the atmosphere of Earth.
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There are commercially available materials (fibers, films, fabrics, textiles) and materials found in trash or in natural surrounding
that are finished HG sails ready for dressing a known HG frame (e.g. buying a replacement sail for production HG).
that may be directly used without modification to make HG sails in one's own loft or at the loft of a sailmaker of one's choosing.
that may be modified by commercial agents for customers.
that may be modified post purchasing or post gathering. One might buy fibers and build up one's own sail from the fibers. One might "purchase" via the purchasing tactic of salvaging from trash some materials and build up a HG sail. Trash Technology. Harvesting.
Finished HG sails potentially are of myriad qualities.
The sail might be made of a net-based tree-leaf aggregate; mount dried leaves to a large-mesh net; dress a HG frame with such and glide.
The sail might be a laminate of several materials.
The sail might be composed of multiple patches where not all the patches are of the same material.
The sail might be adequate for one flight session, not two. Or the sail might be good for daily flying for 10 years. Durability, UV resistance, wearing qualities, etc. will make a difference on how much use time may be had from a given sail. Facing many parameters sails that are satisfactory to pilots may vary wildly as to material specifications. Perhaps a pilot wants a one-flight sail to be used in a movie stunt where the sail will fail knowingly at certain speed-angle-of-attack resulting in the need to use a rescue chute or need to bail out into water from low altitude sail failure designed to occur. Or perhaps a pilot intends the sail to be wet by salt water daily for a flight season because of special operations.
There might be described a most popular set of requirements desired by a pilot group. Sailmakers and owners would aim for material specifications that would serve that faction of pilots. What are some distinct factions of HG pilots and what kind of sails does each faction want? The faction of HG pilots that want to fly once with a homemade hang glider built without spending over $100 may seek sails that fit such budget. The faction of HG pilots that want to compete in speed gliding likely to face firm turbulence will seek sails of sturdy specifications.
There is a host of materials that have historically been used in HGs. Such materials may be described in this topic thread by anyone. There are futuristic materials likely to arrive in some future year; those may be studied and discussed in this topic thread.
There are sail materials used by contemporary hang glider manufacturers. Those materials may be carefully described and discussed. Availabilities? Replacements? Types? Costs? Repair methods? Care? User comments? Longevity? Accidents? Damage causes? How to clean? What to avoid? How to inspect?
Aspects of sail materials are plenty. Each aspect may be studied and discussed. What are many aspects of HG sails. No one will ever produce a list of all the aspects of sails; there may always be an aspect that any given list has missed noting. We do not have infinite time on Earth to discuss such unending aspects; we might seek to discuss what seems important to someone in the HG community. That is, most aspects of sail materials will never be discussed on Earth; we will see what aspects will actually arrive in the discussion thread. E.g., an aspect of commercial sails: "disclaimer" aspect. Patterns? How to make? How to cut?
How to sew, fuse, glue, weld? When to discard and how to recycle, reuse? How to handle HG sails? How to store HG sails? What surface treatments to avoid or use on HG sails? Moisture and sails? Fog and sails? Transporting HGs to protect HG sails? What questions rise up about HG sails in various HG communities? What has been discussed about HG sails? What is the literature regarding HG sails? What are the various ways to put a HG sail onto a HG frame?
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Some teasing starters:
Leaves: http://www.grumpyoldgi?ts.org/johnleaf.htm
High end: https://www.northsails.com/sailing/en/sails/materials
Manual comments about sails, e.g.: https://www.yumpu.com/en/document/read/ ... s-wing-inc
We have in our forum scattered about many comments about HG sails; those might be sifted for gems to be developed in this present topic run.
Some questions:
Will there be a successful hang glider sailed using spider silk as a sail. We know some spiders have put some webs on some HG sails. A HG sail made with spider silk could be very very expensive to make. Story and video:
https://www.vam.ac.uk/articles/golden-spider-silk Caution: There are products called "spider silk" that are not real silk or fiber from real spiders. https://en.wikipedia.org/wiki/Spider_silk Note that some spiders have done hang gliding using their own spider silk as their wings: kiting spiders glide and soar https://en.wikipedia.org/wiki/Ballooning_(spider)