Completed Hammock Sock

**Certain** · 12-19-2006, 23:51

Oh....that's pretty cool. So, let's say it's a cold windy night, how much warmer will it be w/a sock and tarp pitched for cold weather vs. just the tarp? Is a ccf pad still necessary if using a sock or will the wind blockage and quasi-vapor barrier (sock made from silnylon) allow you to warm up enough?

**Just Jeff** · 12-20-2006, 00:52

I've measured over 10F difference inside the sock and outside, but still under my tarp. But that's just the heat near the top of the sock and doesn't really account for the difference in convective heat with and without the extra protected space below the underquilt...so the actual difference is probably higher than what a standard thermometer could measure. I guess putting a probe between the hammock and underquilt, then testing with and without the sock, would be the best way to know for sure. I remember Risk did this with one of his projects...Risk, have you tested the TravelPod this way?

I wouldn't use silnylon...a VB will cause moisture to build up in the insulation if you put it around the outside. Maybe a small strip along the bottom, but certainly not wrapping all around.

Re: the pad...some kind of insulation will be necessary for most conditions, I'd imagine. If you're comfortable to 70F with no bottom insulation, a sock may get you to 60F or so...just guessing. But adding the sock protects the insulation and adds several degrees so I don't have to resort to a pad.

Re: the bug net...I think that would help with condensation. It would also vent some of the heat, though. It would be a tradeoff...lots of bug net would be good for some conditions (humid or warm), a little bit of bug net is better for drier or colder conditions. Personally, I'm happy so far with the zipper approach...I can zip it around my head for cold conditions and still not breathe into it, or I can unzip it to vent if I get too warm or get condensation buildup. But I haven't really field tested it yet.

All just my opinions, obviously...someone may know better science behind it all. But the big thing is that gear has to be suited to conditions, and this is only one option that will be suited to some conditions. Right now, it's an option I like, though.

**Frolicking Dino** · 12-20-2006, 06:29

A question - has anyone ever made a sock that has some light baffling inside the dead air space? My thinking is that it would disrupt the air currents (as down and other insulation do) and lead to a warmer sleeping experience.

**Just Jeff** · 12-20-2006, 10:30

Light baffling without any insulation? Or like an oversized PeaPod? Not sure what you're envisioning.

**Grinder** · 12-20-2006, 10:32

Check out Ray Garlington's insullation methods. He crinkles up newspaper inside a garbage bag and puts that in the dead space underneth. Others use a space blanket.
Still others use leaves.

You're on the right track.

Tom

**Grinder** · 12-20-2006, 12:47

To me, dead air space as insulation is a dead end.

Fellow campers used to complain about freezing on an air mattress. I scoffed.

Then two years ago, I camped at Suches Ga, near Springer Mountain. It went into the mid twenties and I nearly froze to death from the bottom. Finally, in the middle of the night, I remembered my down vest and put it under my bag, on top of the air mattress. Then I got some sleep.

Air seems to convect so well that it is of dubious insullation value.

Tom

**Frolicking Dino** · 12-20-2006, 13:18

Originally Posted by Just Jeff

Light baffling without any insulation? Or like an oversized PeaPod? Not sure what you're envisioning.

As I understand it, the normal convection of warm and cold air within a 'dead air' space is what prevents it from insulating well. If something inside disrupted the air currents, it should keep the heat from being lost as quickly... so a system of baffles (just like those inside down quilts to keep the down in place) or maybe a piece of very light weight material a wee-bit smaller that the sock should (in theory anyway) slow the lost of heat thru convection.

**Coffee** · 12-20-2006, 13:35

Originally Posted by Frolicking Dino

As I understand it, the normal convection of warm and cold air within a 'dead air' space is what prevents it from insulating well. If something inside disrupted the air currents, it should keep the heat from being lost as quickly... so a system of baffles (just like those inside down quilts to keep the down in place) or maybe a piece of very light weight material a wee-bit smaller that the sock should (in theory anyway) slow the lost of heat thru convection.

Interesting thought. Kind of like triple pain windows. I wonder if the the increase in insulation would be enough to off set the weight. Something like that would have to be close to 1.5 to 2 lbs.

**slowhike** · 12-20-2006, 13:44

Originally Posted by teblum

To me, dead air space as insulation is a dead end.

Fellow campers used to complain about freezing on an air mattress. I scoffed.

Then two years ago, I camped at Suches Ga, near Springer Mountain. It went into the mid twenties and I nearly froze to death from the bottom. Finally, in the middle of the night, I remembered my down vest and put it under my bag, on top of the air mattress. Then I got some sleep.

Air seems to convect so well that it is of dubious insullation value.

Tom

i believe the greatest function of the sock & the dead air space it creates is not to insulate, but to simply create a still air space that keeps air movement/wind from whisking away the warm air layer that surrounds the insulation of your top & bottom quilt.
the idea of baffles to stop air movement with-in that dead air space might help some, but i don`t know if it would be enough to compensate for the weight of the extra material. but, who knows?

**Coffee** · 12-20-2006, 13:48

I tested it out last night. Overall it preformed pretty well. I started off with mid weight bottoms and top, socks, and windproof hat. I was using JRB nest, DIY hammock, DIY hammock sock, McCat Deluxe tarp, and Mont bell 20 degree bag.

The temp when I went to sleep was around 30 degrees. At around 6am It was about 15 degrees out. Inside the hammock sock on the ridgeline I measured 46+ at the start of the night and about 37 in the morning.

I was pretty comfortable for a few hours. I got in the hammock at 6pm. I started to get a little cold on the butt area and put my jacket underneath me. This worked out pretty well for awhile. In the middle of the night I woke up even colder there and added a pad under my butt only. I figured in the middle of the night was the as good of time as any to cut a section of my pad off. I woke up around 6am or so pretty cold underneath. I added the rest of my pad underneath and way pretty warm after a few minutes.

I think Jeff was on to something concerning the temp. I think the only way to really measure the temp increase is to measure the temp at different places and compair to no sock. Maybe the best place to take it would be next to your skin both ontop and below. In the end that is the only place that really matters. It is nice to breath in warmer air though.

I still got some condensation. It wasn't nearly as bad as with my other version. It wasn't bad enough to worry about in the morning. Minus a few watering breaks I spend about 12 hours in there. I was thinking about netting about where my face would be, but as Jeff said that would vent some of the heat.