Ohh, cordura and contact cement. Perfect example of using adhesives and fabric as a reasonable means of joining the 'angles vs traditional filament tape.
My grandfather also recommended contact cement, as it's waterproof. Using a brush applicator would also make application a little more accurate. Have you tested this combination in an outdoor (windy and/or wet) environment? On Thursday, March 28, 2013 1:52:26 PM UTC-7, Vladimir Khodel wrote: > > Yeap, turns out contact cement (not water based version, do work outside > and don't smoke anything while gluing :)) and cordura work great for > hinges. Although beefy brass zippers can be found on clearance when buying > in bulk, I think more cordura flaps and some velcro to keep things from > unfolding would be sufficient: > > http://www.appropedia.org/BFD_mod > > Good luck and let me know if I can help in any way :) > > Vladimir > > > On Thu, Mar 28, 2013 at 1:17 PM, Jacob Rodriguez > <[email protected]<javascript:> > > wrote: > >> So, I'm going to be building a quarter sized nearodesic polyhedron >> ("quad") dome (1 rmax sheet = 8 triangles) for BRC this year. >> >> My foamcore and masking tape prototypes (1:12 and 1:5 scale) have been >> going well. I'm learning how to do the tape hinges, and how to miter the >> edges with a razor and angled metal guide. I'm thinking that the full size >> version will be relatively easy to prepare and construct. My end result is >> a 6' high, 12' diameter dome that folds down into a 4' x 4' x 15" high box. >> Minimal tape is required as all but one edge of each quad is hinged with >> fabric and adhesive. Only the top square, and 4 "corners" need to be fully >> taped together. >> >> I'm seeing lots of people commenting on how the BFT (bi-filament tape) is >> not really UV resistant, so it flakes off eventually. Also, that it's >> barely a semi-permanent solution, even if you do tape hinges instead of >> one-time assembly. I've considered many different types of ways to join the >> triangles that would last more than one or two times: >> >> - zippers (needed like 400 of them, really really expensive) >> - button snaps and straps (would glue on the snaps to the boards, then >> use a strap to snap them together; this is not weather proof at all) >> - velcro (again, pretty expensive if you use the really good velcro, >> which is likely the only way to guarantee structural integrity and >> 'weatherproof-ness') >> - magnets (even using strong ones (N45), embedding them in the edges of >> the triangles, they could jsut fall out, and still not weather proof. also >> $$$) >> >> ..and a couple of other ideas. I've learned that putting metal >> hooks/rods/bolts (binder clips) through the boards will just rip through it >> with a strong enough tug. They could end up just getting loose and boring >> out big holes. Using plus-shaped ("+") hooks/rods to fasten some sort of >> fabric over the joints are slightly better because they resist being pulled >> like a wire cutter through the board, but you would have holes in the board >> and water could get in. Also, excessive force would also just make the >> holes looser and ruin the boards eventually. But the idea of using some >> sort of fabric seems to hold merit. >> >> My main goal is to build something that can easily be packed away, and >> assembled multiple time. Realizing that the main principles of a good BM >> structure are to seal out rain, dust and light, I think I've come up with a >> possible solution, but I'm curious why I can't find anyone who has tried it. >> * I'm hoping to get some cautionary tales or some encouragement on using >> sport nylon (as opposed to ripstop), and some Super 77 or 80 or 90 spray >> adhesive, instead of the traditional tape.* >> >> The cost might be a little more expensive up front (depending on some >> factors), but I'm thinking that the nylon will last much longer than just >> about any tape and is probably just as strong (if not stronger) than BFT. >> From what I've read, a lot of people end up using some 77 spray anyway >> because of the lubricating residue on the boards. I'm curious if it's more >> UV resistant (or at least the adhesive would be) and therefore survive the >> endless sun bathing better. Also, the concept of cutting fabric into strips >> and using spray adhesive as a backing gives the user many more options when >> it comes to materials (stronger fabric and/or stronger glue), rather than >> just limiting to such a rare find as 6" BFT. Though I'm sure that sport >> nylon "tape" is even more rare. You can also make the strips as wide as you >> want, so you are not limited there either. >> >> I've built a prototype of a hinged triangle using foamcore, sport nylon >> and Super 77, which seems very, very strong. Stronger than masking tape >> anyway. I'm thinking that while it's not waterproof out of the box, I could >> always spray with some scotchguard, or tape over everything with the foil >> tape. Foil tape would also help any concerns on fire-hazard as the adhesive >> is quite flammable. I put a hairdrier on it for about 10 mins on high, to >> see if excessive heat made the glue loosen, but it did quite well. I'm >> thinking the higher temp ratings of 80 or 90 adhesive will help in that >> area. Maybe instead of foil tape. I can spray with some sort of coating >> that will protect against fire and water at the same time. >> >> For cost comparison, my project would be using about 6 rolls of 60yd >> tape. That's about $20 a roll. Plus about 4 rolls of foil tape (for outside >> only) at another $20 a roll. I'm thinking that a can of adhesive will last >> quite a long time, so I may only need about 3 cans at about $20 a pop. The >> fabric is not that expensive (maybe 5 dollars a yard), so I think all in >> all, I might come out saving a little cash (if any at all), but ending up >> with a much more permanent/reusable solution. >> >> Anyway, what do you all think? I'm going to be purchasing a piece of >> polyIso to test. I'm going to make a single "quad" using this nylon and >> adhesive, then leaving it up on my roof for a week or two to see how it >> handles the weather. It's Santa Monica CA weather so not quite the same, >> but should give a good indication as to whether it will survive at all. >> >> Thanks for reading! >> >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "hexayurt" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected]<javascript:> >> . >> Visit this group at http://groups.google.com/group/hexayurt?hl=en. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> > > -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/hexayurt?hl=en. 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