Feb 23, 2009 at 7:33 pm #1234290
So I ordered some nylon from Thru-hiker and had an idea; what if I just attached the nylon to the bottom of my Big Agnes Aircore on two sides, then had the third side loose to wrap around the sleeping bag as needed. Wouldn't this provide protection from wind drafts and rain splatter in conjunction with a tarp? As well as a little protection from dew and condensation?
And would Gorilla Glue work in this application?
Thoughts?Feb 23, 2009 at 7:37 pm #1480217
It would work just fine, I used a cheap blue 8×10 tarp folded in half for years. Just put the closed side to the wind and you will stay warm and dry all night nothing else needed. AliFeb 23, 2009 at 7:38 pm #1480219
i've actually been thinking similar thoughts recently – mostly i was wanting to be able to fit my inflatable pad inside the bivy with the sleeping bag; with one bivy i have no problem, but the lighter bivy is too tight to fit both pad & sleeping bag or quilt
i used gorilla glue to fix the plastic door shelf in our refrigerator recently & i'm impressed with how well it is holding (it had cracked along the bottom front edge almost the full length of the shelf) – my guess is that it would hold
it would be a cheap AND a very light solutionFeb 23, 2009 at 7:44 pm #1480222
I mean, with an inflatable pad you don't really need a bottom to the bivy. If you have rain that is up 2.5", you need to pick up and move to a better location….so why not just get rid of the bottom and use the pad. It is waterproof, after all.
Well, I'm gonna do it as soon as the nylon comes. I'll let you guys know how it goes.Feb 23, 2009 at 7:46 pm #1480225
Ali, did you do that with another tarp overhead? Or sailor-style, just wrapped up in it?Feb 23, 2009 at 7:48 pm #1480226
not for moisture protection, but to help keep grit off of the pad a bit more & hopefully extend its life
but i have put the aircore straight on the ground before – and if the virtual bivy is attached to the top of the pad, the issue of seepage is pretty much nil, whereas if the pad is inside the bivy, you could get seepage along the bottom seam, which could wick up into the bag/quilt, so it could be a more mechanically sound design/system as wellFeb 23, 2009 at 7:54 pm #1480230
I just wrapped up in it. You can put it anywhere and it take one second to upack and repack. It is far more weather proof than you think. Its just not as social as a big tarp with your buds. AlFeb 23, 2009 at 7:58 pm #1480232
anytime i've used a non breathable cover for me or sleeping bag, i've had LOTS of moisture from condensation
since switching to breathable covers, no problemFeb 25, 2009 at 9:18 pm #1480843
Try a piece of Tyvek ….. you'll love it.Feb 26, 2009 at 4:28 pm #1481049
So I did it today….
I decided against attaching the nylon to the pad and came up with a easier solution.
I took a polycro ground cloth from Gossamer Gear and a corresponding piece of 1.1oz ripstop nylon…..I attached the pieces together using Gorilla Tape (a bit heavier than glue, but foolproof).
The bivy is very similar to the Heatsheets Bivy in design, but it is breathable thanks to the nylon. I'm going to test it out sometime this month. Should do the trick for 25 dollars!Feb 26, 2009 at 6:19 pm #1481078
@daveheissLocale: Pacific Northwest
I was thinking of doing much the same thing – polycro floor and nylon or tyvek top. All I really want a bivy for is extra protection from cold wind (in my Contrail), and this thread has been very helpful.
Did you leave one side open to tuck in or did you make a tape seam on both sides?Feb 26, 2009 at 6:38 pm #1481082
I've slept in the heatsheets bivy several times (with much condensation, don't recommend it) and realized that I don't like the end above my head open as it is difficult to close off the bivy to protect from drafts coming from behind your head down into the bivy.
So, I taped the two short sides (head and foot) completely, and taped the entire length of one of the long sides. On the last long side, I taped about 3/5 of the length and started from the corners but left an opening towards the head area. So there is a footbox and a headbox, with the entrance in the center.
Also, I left about 2 spare inches down the partially open side so that I can tuck the bivy in around my head if it is cold or clip it up if not. In anycase, I prefer this because you have protection from behind your back, above your head and below you, and if you get drafts from the section open, it is easy to manage if you lay on your side and hold the bivy with your arms. Since I'm a side sleeper, this works best for me.
The polycro ground sheets are 40 inches wide and this is almost exactly the right size for someone using an inflatable 2.5" mattress….if you sleep on something smaller, then you could go with a smaller width.Feb 27, 2009 at 10:24 am #1481234
@walksoftlyLocale: Piney Woods
I found a woven nylon shower curtain liner at Target. Very breathable and waterproof. (And lovely designer pastel colors). Good source of WB fabric for projects.
Be sure to cut out the weights at the bottom!Feb 28, 2009 at 9:12 am #1481502
Great idea Nathan! I (inronically I guess) sewed up a version of your bivy using the polycro ground cloth and some cheap DWR nylon from Walmart.
It goes together extremely quickly and easily since you are only dealing with rectangular pieces of fabric and straight seams. Even better, the polycro is transparent so it's easy to match the edges with the fabric when sewing.
I'm wondering how the seams will hold in the polycro, and have added some duct tape patches on the stress points. Tried it out indoors last night and it seemed to hold together fine.
Next is the backyard test.Mar 10, 2009 at 12:45 pm #1484366
So I managed to use the polycro/nylon Bivy I made using Gorilla Tape to seal it up and have a few observations.
First, the Gorilla tape is really good at bonding nylon and polycro, but it is heavy. Sewing would obviously be a lot lighter, but wouldn't work with polycro, I suspect. Second, polycro is not very wind-proof. The bivy was drafty compared to my Oware Sil/Nylon bivy. This could be remedied by using a lot more nylon than polycro so that the polycro does not lift up on the sides. Third, I could not get the velcro to bond to the polycro! I used a special plastic glue that require priming and while it initially bonded, the pulling of the velcro slowing tore it off the polycro. If I were doing this again, I'd just skip the velcro and have a semi-open bivy.
Other than these problems, it worked great and is a cheap, easy solution for anyone who wants to see if they like the whole tarp/bivy thing before investing in an expensive bivy.
Pictures to come.Mar 10, 2009 at 1:00 pm #1484371
I made a ventilation window with nylon netting (less than a dollar's worth) and then attached a small grommet so I could put some string through the grommet and use a clip on the other side to adjust the height. Worked pretty well for an alternative to sewing a tie-out.Mar 10, 2009 at 2:59 pm #1484406
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
> the Gorilla tape is really good at bonding nylon and polycro, but it is heavy.
Any reason why you couldn't use ordinary brown 2" wide packaging tape? Very light, sticks like mad, quite strong.
CheersMar 10, 2009 at 3:38 pm #1484422
Well, I guess I just wasn't convinced it was up to the job….but your glowing review of it is making me reconsider. It is a hell of a lot lighter, that's for sure!Mar 10, 2009 at 3:41 pm #1484423
@vickrhinesLocale: Central Texas
I'll second packing tape for a cheapie bivy. It will get grody as dirt works under the edges, but don't you don't need to worry about strength.
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