Spinnaker as bivy bottom

Like silnylon, it's tough enough if you are pitching it on leaves, dirt or other soft substrates. Pitch it on rocks and you'll find points of wear popping up pretty quickly, but the same is true of silnylon. It's waterproof enough as long as you aren't pitching it on puddles. Though it's not more waterproof than silnylon, it's not so much less waterproof that you'll be able to really be able to tell the difference in its performance as a bivy bottom. However, unlike silnyln, it's so insanely noisy you'll most likely regret using it on something that will be 1-2" away from your ear (I know I did). It's like a plastic grocery bag that won't shut up. Silnylon is a superior choice for an ultralight bivy bottom due to the fact that it is so much quieter. Much easier to get a good night's rest when the ears can rest.

run your sheet of Spinnaker through the washer several times before sewing it on the bottom ….. that'll take care of the noise issue. At least it did on mine.

Washing several times in the washing machine will likely
degrade the coating and calandering on the spinnaker.

This may make no difference to you for that use if you have
a waterproof pad tho.

LK,

I am a former Gossamer Gear designer and the fellow who originally brought Spinn to the outdoor industry (the stuff Gossamer, Thru hiker, MLD, etc. use), so I have a ton of experience with it.I made a bivy sack using spinn as the base and quantum as the top many years ago, and have yet to have any trouble with it. As has been posted above one needs to be careful what you sleep on top of, but as ultralighters (and hikers with basic common sense) my assumption is that we all are. After three seasons I decided to fill my bivy with a bunch of water and hold it up like a water balloon to check out the degradation. Even then there were no leaks, not even pin holes.

You can decide for yourself about noise but it's never kept me from a good nights sleep. Maybe some of those wax type earplugs could be something you could carry on your first couple of outings in case you find the fabric noisy.

I still have a bit of white spinn cloth here if you want to buy some. I can also get you the gray stuff if you want to – I just don't have any here at the moment. $13/yd plus shipping.

Anyway, hope that helps.

Mike Maurer

maurer@earthlink.net