Thanks for the extra info, Kyle. That's some pretty cool info that I've never heard. I assume the tighter weave of the tafetta is what makes membrane slightly less breathable than similar deniers in a ripstop weave?
Thanks for the extra info, Kyle. That's some pretty cool info that I've never heard. I assume the tighter weave of the tafetta is what makes membrane slightly less breathable than similar deniers in a ripstop weave?
Does RSBTR make any fabric besides the HypderD 1.0 that is not calendared? This would be used as the top half of the sock.
Hey all piggy backing on this post cause I'm planning on making a TQ. Originally thinking silpoly but someone said that want a great choice. What would y'all recommend?
I would definitely not recommend anything waterproof for a quilt, at all. I would use Membrane10, Membrane 15 or HD 1.0 Calendered.
I'm not sure I follow the debate... perhaps because I'm not a fan of top covers overall.
Membrane 10 would be plenty IMO. HyperD 1.0 for a budget option.
Calendared for wind resistance as that seems to be the primary function, in addition to making a bit of a microclimate.
Breathable is a moot point/paper only spec IMO in this application....
You're adding the top cover in temps below freezing, even if you create enough of a microclimate in your hammock (with an unvented top cover) to maintain temps above freezing... the vapor has no place to go.
In real life- despite the internal air temperature the fabric will be at or very near the external temperature. So any vapor that reaches the fabric to evaporate will condense and form frost on the fabric's surface. In theory you may develop frost inside and out... in practice I can't recall this happening... frost always forms on the inside.
Shug's frost bib is a great example of how best to deal with moisture from breathing... and a good demonstration of how unlikely any vapor is to reach your top cover and pass through. That stuff is snow before it travels a few inches.
I've built winter bivy sacks out of true WPB materials... the only way to keep frost off your face is a vent or double wall design at the head and feet. You will still from frost on the shell of your sleeping bag/inside of the fabric unless temps are close to freezing. Once you hit 20* or so all bets are off and the best you get is the vapor clears the shell of your sleeping bag and forms there. Packing up a bivy in the winter means turn it inside out and dump the snow you made overnight if all things worked out right. If you're talking true winter you use a VBL for your body and vent your breath to keep it away from your insulation.
Personally I think the 'weight' is better spent on a winter tarp and insulation. Let's any vapor you crank out to dissipate or hit the tarp. Size the tarp big enough to cut the wind. If you get a super bad night- you can seal the tarp up like a sock/top cover and get a better microclimate out of it too.
I could be missing something... not trying to pick on anyone.
I've never made a top cover but a decade or two of using bivies is informing my thoughts on the subject. And part of what I like about hammocks is the openness so the desire for the top cover never really appealed.
When you're talking true winter (20* and under) where there is no shot of dealing with liquid water... calendared and DWR bivy sacks have been the best fabrics in my experience.
If you're leaving the tarp at home and using a top cover instead... I guess I could see that appeal. But again I'd rather have a small vent at the RL since I'm not worried about rain pouring in. You want your moisture to get out... not snow on your insulation. If you're near freezing there is a good chance you will keep it warm enough that it can get into your insulation again. Frost is easy to deal with... it just dusts off.
I know it's off topic, I just don't follow the conventional hammock wisdom regarding socks and top covers as it contradicts other styles of winter camping wisdom.
Thanks for the info!
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