View Full Version : Hammock Sock Condensation Issues/Questions
I just got done from testing my hammock sock and want to post a question and some obervations while they are fresh in my head.
This is my 3rd or 4th night using my hammock sock. The other times I did not see any noticeable condensation. The outside temps were only in the high teens and twenties. This time was a completly different story. When I got in my hammock the outside temp was 8 F with a wind chill of -2 F and a dew point of -3 F. When I got out it was 4 F with a wind chill of -7 F and a dew point of -6 F.
After about an hour I started to notice some condensation. Nothing too bad. However by hour 3 I noticed a lot of condensation. I used a fleece to wipe off some of the condensation. But it reformed pretty quickly. It got to the point that whenever the hammock moved I felt a little mist in my face. Not to fun or good for me keeping my bag dry.
I was really toasty other than this. The temp inside the sock on the ridgeline above my chest was in the low 40's. Around waist level it was in the high 20's. The sock was doing a good job of blocking the wind and traping in the heat.
The bottom 2/3 of the sock is DWR and the top 1/3 (from about shoulder to shoulder) is uncoated ripstop.
Is this just a cold weather condensation issue? Any thoughts on stopping this? I know this has a lot to do with dew points and nylon breathablity.
I am considering adding a noseeum 'window' above where my head is to vent some mosture. But that would vent some heat. This could give the effect of a double wall tent vs a single wall.
Just Jeff
02-06-2007, 06:22
Interesting observation. I wonder if it has more to do with the low temperature or with the dewpoint. At some point, you're just going to be damp...short of precipitation, humidity inside the sock will always be a bit higher than humidity outside, I think.
But dew should act like precip, no? It condenses and falls from the air, rather than being everywhere like humidity. Or maybe I misunderstand how that works. Interesting in hearing what smarter folks have to say about it.
That's one reason I wanted a zipper in mine...I can stick my head out and get rid of the biggest moisture producer (and hot air producer) - my mouth.
That was kind of my thought. I was hoping the smart people would chime in. Was it so cold that the mosture in my breath basically came out as more of a liquid than a gas?
I was able to pull it back so that my head was uncovered. I think it would have worked. But now I was breathing in air closer to the outside temp, then the warmer air inside. That really isn't fun. On a side note, Jeff I think you are right to use a zipper. I think it would be easier than just the one opening.
Temps this low while hiking are pretty rare. But something to consider.
Nice to see that I'm not the only one here who does not sleep.
slowhike
02-06-2007, 06:59
i'm getting the impression that having the zipper to be able to stick your head out is going to be just about the best answer... especially in that small of a space.
A week or so back, we had a mini cold front in florida, I tried out a new idea to cope.
I used a poncho liner I have. It has ties on it at each corner. Rigging it over the ridge line, I tied two corners together, around the foot of the hammock. The liner is 8 feet or so long, so it reached well past my head.
I could get in the hammock, I now use two pads, so they surrounded me on the bottom and sides.
With the liner pulled up past my head, hanging over the hammock,I was cosy as could be. I left an air hole a foot beyond my head.
In higher winds, this might not work without more fasteners, but with some elastic cord. I think it can be adapted.
Miles of smiles
Tom
A week or so back, we had a mini cold front in florida, I tried out a new idea to cope.
I used a poncho liner I have. It has ties on it at each corner. Rigging it over the ridge line, I tied two corners together, around the foot of the hammock. The liner is 8 feet or so long, so it reached well past my head.
I could get in the hammock, I now use two pads, so they surrounded me on the bottom and sides.
With the liner pulled up past my head, hanging over the hammock,I was cosy as could be. I left an air hole a foot beyond my head.
In higher winds, this might not work without more fasteners, but with some elastic cord. I think it can be adapted.
Miles of smiles
Tom
Interesting idea. You get the warm air space inside with less weight. The drawback would be to air cooling the bottom. Not as big of a deal with only using ccp underneath.
Got any pics to share.
headchange4u
02-06-2007, 08:46
The first thing that comes to mind is some sort of venting system. You are basically putting a tent around the hammock. Tents will have some serious condensation problems if they are not properly cross-ventilated. Maybe a couple of small vent holes that can be opened up.
It just may have been the really low temps that caused your problem.
blackbishop351
02-06-2007, 08:52
HE - Did you try opening up the drawstring some? I made sure to leave a bit of a hole on the foot end, and then at Rogers Jeff suggested pulling the head end closer to me and letting it stay open a bit, too. Combined with the airflow you've still got through the nylon, that should give you plenty of ventilation.
I tend to follow the philosophy that says that the simplest solutions are often the best ones - that's why I made a sock rather than a pod in the first place. I haven't tried it yet, but I think dropping the sock off the ridge - so that it wraps my body closer but leaves my head exposed - may be the best idea in really REALLY cold weather.
I had the head end open some. I think that my breath kept going in the and up, and then condensing on the sock.
When I leave my head out it works, but then I'm breathing in cold air.
If I make another one with a drawstring, or if anyone else does, I am going to make the sleve the draw cord goes through bigger. I had problems fully closing the end. I noticed that before I had been leaving the head end pretty open.
blackbishop351
02-06-2007, 09:11
Maybe the pores in the nylon are just going to close up past a certain temp, like Jeff said.
I think I made the drawstring channel on mine so that the string would have about a 1" opening to run through. I haven't had any issues. What size cord are you using? That can make a difference too - a larger diameter cord will help just as much as a larger channel.
Maybe the pores in the nylon are just going to close up past a certain temp, like Jeff said.
I think I made the drawstring channel on mine so that the string would have about a 1" opening to run through. I haven't had any issues. What size cord are you using? That can make a difference too - a larger diameter cord will help just as much as a larger channel.
Now that you word it like that it makes sense. If when it is really cold the water vaper in your breath gets bigger, and that size is greater than the pore size in the nylon then it won't go through the material.
I used the grossmergear spectra that is super thin. The problem is that I wasn't thinking and made the seam too small for that. I think it is more the bunching up of the seam than the size of the cord with mine that is causing problems.
Last Friday night I camped at Savage Gulf. The temp at 10:00pm was 8°. My tent is a Hubba which is basically mesh except for the floor. I did have the rain fly on but I still get great ventilation. I woke up Saturday morning with more frozen condensation on the inside of my tent than frost on the outside. My tent poles were frozen together. I had to warm them up to get them apart. The condensation was worst where my head was.
When you warm breath hits the cold material it freezes. If you are a heavy breather or snorer then you will have more condensation than someone who doesn't.
Now in my tarptent I sleep with my head at the front of the tent which is mesh. That allows my breath to escape and not form on the top of the tent.
This is from a tenter so you may want to disregard anything I say :p
blackbishop351
02-06-2007, 13:07
Now that you word it like that it makes sense. If when it is really cold the water vaper in your breath gets bigger, and that size is greater than the pore size in the nylon then it won't go through the material.
I used the grossmergear spectra that is super thin. The problem is that I wasn't thinking and made the seam too small for that. I think it is more the bunching up of the seam than the size of the cord with mine that is causing problems.
I think it might be more the material itself shrinking and causing condensation. Just like when you heat something, cooling it shrinks it symmetrically, so the holes in the weave of the fabric might actually be getting smaller. Think about a net made out of shock cord - when you let go of it, the spaces between the cords get smaller, not just the perimeter.
I don't know what size you made your channel, but try using a slightly larger cord. You might be surprised.
Last Friday night I camped at Savage Gulf. The temp at 10:00pm was 8°. My tent is a Hubba which is basically mesh except for the floor. I did have the rain fly on but I still get great ventilation. I woke up Saturday morning with more frozen condensation on the inside of my tent than frost on the outside. My tent poles were frozen together. I had to warm them up to get them apart. The condensation was worst where my head was.
When you warm breath hits the cold material it freezes. If you are a heavy breather or snorer then you will have more condensation than someone who doesn't.
Now in my tarptent I sleep with my head at the front of the tent which is mesh. That allows my breath to escape and not form on the top of the tent.
This is from a tenter so you may want to disregard anything I say :p
This is actual pretty relavent to what I am seeing. I was basically sleeping in a single wall tent. It wasn't frozen on the sock though. I think the temp was above freezing on the sock. There was no frost on it. All the mosture was liquid. Frozen would have been better.
I am liking the idea of a cold weather model with some sort of mesh to vent my breath. Steeling yet another idea from you tenters.:p
I think it might be more the material itself shrinking and causing condensation. Just like when you heat something, cooling it shrinks it symmetrically, so the holes in the weave of the fabric might actually be getting smaller. Think about a net made out of shock cord - when you let go of it, the spaces between the cords get smaller, not just the perimeter.
I don't know what size you made your channel, but try using a slightly larger cord. You might be surprised.
Gotcha. I am used to thinking about electrical stuff that you cannot see. That leads me to overlook some of the obvious. It actually happens a lot when I make stuff.
The channel is pretty small. The more I think about it. It was working well with the head end open at higher temps, maybe a cold weather version is inorder. If anything else it gives me a reason to make something else. I can almost hear the sewing machine come out now.:rolleyes:
Nice reports, I had a very minor condensation issue at the Pa. Ruck. The temps. were around 14 degrees. I was in my hennessy, with hhss,nest on bottom. 20 degree wm bag as a quilt. i was using a 8x10 sil tarp about 2.5 feet above the bug netting. the area of condensation was on the bug netting about the size of my hand near where my head was. So i can see where you would get some with other set ups as the bug netting is very breathable. It was strange to see it attach it self to the bugnetting and than little by little it built on its self crystlizing. really was not a big issue as it was a small area. hammock engineer, its nice to read your detailed reports hope to see you on the trail. I leave on the 26th of march doing the approach trail.
HE,
Your wish is my command. I uploaded a few pictures of the set up.
It's hard to get good pictures with all this sunshine today. (Eat your heart out!!<G>)
http://www.hammockforums.net/gallery/showimage.php?i=482&c=14
This pic and the next three.
I noticed I didn't really tie the corners together. I got the center to one corner.
When I was in it, I just arranged it to drape over both sides.
Miles of Smiles
Tom
The Breeze
02-06-2007, 16:46
when I made my hammonk cover I put a hole right over the head and have sleep in it 6 time cents then and no condensation at all. even on mount rogers, and I stayed warm every night. this said your body produces as much as two quarts of water in 8 hours it has to go somewhere if it is warm and dry out side evaporation will take care of it, but when its cold and dry the heat to make it exchange is not there so it forms into water droplets and freezes if it cold enoff same thing with you ac at home took a class one time heheheh hope this helps
Just Jeff
02-06-2007, 21:10
FTR, I didn't say the material shrinks or anything about pore size. It probably shrinks some, but I doubt the condensation has anything to do with pore size...I've seen breath freeze on bug net mesh before. It's probably more a function of the cold temps making the material so cold that the moisture condenses/freezes on contact rather than venting through.
Great idea on the poncho liner.
blackbishop351
02-06-2007, 21:23
FTR, I didn't say the material shrinks or anything about pore size. It probably shrinks some, but I doubt the condensation has anything to do with pore size...I've seen breath freeze on bug net mesh before. It's probably more a function of the cold temps making the material so cold that the moisture condenses/freezes on contact rather than venting through.
Great idea on the poncho liner.
Sorry about the misquote...it was late :p
slowhike
02-06-2007, 21:46
i could go back to the zipper thread w/ this but because you're talking about socks & travel pods & that's what i plan to use it on, here's my question.
on the quest sight i saw in the zippers a couple options that caught my attention.
both are 2-way, separating zippers...
#5 coil... 96" (8')... $5.95
#8 coil..110" (9' & 2") ...$7.99
i'm wondering about coil vs teeth... weight & trouble-free operation?
i'm thinking it would be good if the zipper separated (on one end anyway).
reason being, i would have a shorter zipper going from the center/top of the sock, at the separating end of the zipper (head end) that would go down the side.
that would allow you to open one side up for enter/exit, to grab something, or to heat water, w/o pulling the sock down.
i might would have a short zipper on each side to be able to make a door/window on either side.
It sounds like some interesting options here. Everyone has a different take on the same basic principle. In terms out how to inclose their hammock.
I think that at a certain temp, I am going to have to vent my breath out and not into my sock. I don't think I am going to see many nights like that on my thru.
i could go back to the zipper thread w/ this but because you're talking about socks & travel pods & that's what i plan to use it on, here's my question.
on the quest sight i saw in the zippers a couple options that caught my attention.
both are 2-way, separating zippers...
#5 coil... 96" (8')... $5.95
#8 coil..110" (9' & 2") ...$7.99
i'm wondering about coil vs teeth... weight & trouble-free operation?
i'm thinking it would be good if the zipper separated (on one end anyway).
reason being, i would have a shorter zipper going from the center/top of the sock, at the separating end of the zipper (head end) that would go down the side.
that would allow you to open one side up for enter/exit, to grab something, or to heat water, w/o pulling the sock down.
i might would have a short zipper on each side to be able to make a door/window on either side.
I'm not sure which, I think it would be coil, but I would go with which ever would snag less on gear or nylon. In the middle of the night I could see a zipper that long aciddentally putting a tear in a quilt.
slowhike
02-06-2007, 23:04
It sounds like some interesting options here. Everyone has a different take on the same basic principle. In terms out how to inclose their hammock.
I think that at a certain temp, I am going to have to vent my breath out and not into my sock. I don't think I am going to see many nights like that on my thru.
yep, i would also have the option of opening the zipper enough to put my head out like jeff talked about.
Does anyone know of a good baclava, but instead of a full head cover just a face cover, that warms the air you breath in?
I have heard the some full bacl. do. I just do not like the full head ones. I also do not like things tight around my neck. The one I have now velcros in the back to stay on, but does not warm the air.
This would fix my problem of why I do not want to stick my head out in cold weather.
slowhike
02-06-2007, 23:12
i belive that would be a pretty easy DIY project for you to design & make.
i belive that would be a pretty easy DIY project for you to design & make.
Maybe, or at least mod a new one.
On a side note, you know you have DIY issues if you mom calls you and tells you about a good deal online she finds on an industrial grade sewing machine.
HSN has a singer industrial if anyone is interested for $200. I think the big difference is a 60% stronger motor. If it had that and a larger bobbin, I would consider it. Altough I think my second old used sewing machine is about to die. I must be doing something wrong.
blackbishop351
02-06-2007, 23:40
This is what I got right before the Rogers trip:
http://www.rei.com/online/store/ProductDisplay?storeId=8000&catalogId=40000008000&productId=47925761&parent_category_rn=40003705&vcat=REI_SEARCH
Is that the kind of thing you're talking about? I didn't end up using it, but I think I probably would've if there hadn't been so much conversation going on...
On a side note, you know you have DIY issues if you mom calls you and tells you about a good deal online she finds on an industrial grade sewing machine.
at least she didn't call and say you will make someone a good wife :eek: ;) :p :p
This is what I got right before the Rogers trip:
http://www.rei.com/online/store/ProductDisplay?storeId=8000&catalogId=40000008000&productId=47925761&parent_category_rn=40003705&vcat=REI_SEARCH
Is that the kind of thing you're talking about? I didn't end up using it, but I think I probably would've if there hadn't been so much conversation going on...
I have one like that that I like. I heard somewhere that there are ones that will warm the air you breath in. That is closer to what I want.
at least she didn't call and say you will make someone a good wife :eek: ;) :p :p
I usually hear that when I sew and then decide to make cookies just to top it all off.
blackbishop351
02-07-2007, 00:21
On a side note, you know you have DIY issues if you mom calls you and tells you about a good deal online she finds on an industrial grade sewing machine.
Lucky SOB! I had to endure my 70-year-old half-crazy machine repair guy to find a nice, solid vintage machine. It's an off brand - I need to look up the serial number and see who made it - but it's a 60's or 70's model. All steel, no plastic, hemming foot, WORKING buttonhole setting, plus about 7 different decorative stitch settings, some of which I think will actually work well for stitch-ends.
Drawback is, it's PINK :o
Just Jeff
02-07-2007, 06:55
HE, you're talking about an exchanger. It keeps the moisture and retains some of the heat in your breath, but adds a bit of resistance to breathing from what I hear. Never used one myself, though. Pretty sure BGT has some reviews.
HE, is this something like you're looking for?
Psolar baclava
http://www.psolar.com/id5.html
I don't have one but I've been eyeing them
I'm thinking of making something similar, one version I found was here: http://www.crazyguyonabike.com/doc/page/?o=lt&page_id=31521&v=7l#pic_85062
he uses a Hennesy, & his 'Sock" is a sheet of plastic.
Note the breathing hole above his face.
Doctari.
slowhike
02-07-2007, 10:49
Maybe, or at least mod a new one.
On a side note, you know you have DIY issues if you mom calls you and tells you about a good deal online she finds on an industrial grade sewing machine.
HSN has a singer industrial if anyone is interested for $200. I think the big difference is a 60% stronger motor. If it had that and a larger bobbin, I would consider it. Altough I think my second old used sewing machine is about to die. I must be doing something wrong.
a note on the industrial sewing machine... from what i've been told, not only are they much stronger, but they sew extremely fast.
i would suppose you could control the speed like you do on the others, but if you press to hard it may go into warp speed!
also i was told that they usually don't have many extra features like the home machines. they are just made for fast, production sewing.
i don't really know about all that, but might be some thing to ask about before you go & lay the money down.
headchange4u
02-07-2007, 11:16
I am looking for an upgrade to my machine. I can live without the bells and whistles as long as it's a good solid machine. The I am using now is starting to sound "clunky" and it has developed a problem sewing through thicker materials.
has anyone ever looked at http://www.freecycle.org/ You can go to the main website and see if there is one in your area. You will be surprised what you can find or give away. I missed a working (good condition)sewing machine in a cabinet with a chair and all the extras by 1-2 emails.
HE, is this something like you're looking for?
Psolar baclava
http://www.psolar.com/id5.html
I don't have one but I've been eyeing them
Thanks, that was exactly what I am looking for.
I am looking for an upgrade to my machine. I can live without the bells and whistles as long as it's a good solid machine. The I am using now is starting to sound "clunky" and it has developed a problem sewing through thicker materials.
I burnt out one. Now the my second used one is making that clunking noise too.
I am putting some research time into this. The ones I was finding yesterday online do sew really fast as slowhike said. They also only go forward and reverse, with only varying stick length.
That's really all I need. Zig-zag would be nice to do bar tacking. This is usually how I attach straps and pullouts. My box with X's never turn out right.
blackbishop351
02-07-2007, 19:11
I burnt out one. Now the my second used one is making that clunking noise too.
I am putting some research time into this. The ones I was finding yesterday online do sew really fast as slowhike said. They also only go forward and reverse, with only varying stick length.
That's really all I need. Zig-zag would be nice to do bar tacking. This is usually how I attach straps and pullouts. My box with X's never turn out right.
My original one is starting to clunk too. Good thing I just got that heavier-duty one.
As far as the box stitch, just practice on some scrap. I had trouble with those for quite a while too - hence the use of bartacks on my homemade slapstraps - but I used all boxes on my gearskin and I'm happy I did. They're no problem at all now.
headchange4u
02-10-2007, 12:56
I am getting ready to build myself a hammock sock. I have a question for those who use one.
How big is the sock at it's widest point? What's the circumference?
Mine's pretty oversized. I do not like things close to my face. I measured down from my ridgeline to the lowest point in my hammock with me in it. I added 4" for the underquilt. I then measured the widest point with me in it. I used that as the size of my circle. I think I came up with 90" wide. I tapered the foot end to saze a little weight.
A couple thoughts after making a couple. If you put a zipper closure and taper both ends, it will come out a little lighter. It may make it easier to stick your head out. If you use a drawstring, make the chamber where the string goes through extra wide to account for the bunching of the fabric.
I only really close me all the way when it was really cold. I like the uncoated at the top to increase breathability. Try to make it so that when in use the sock doesn't touch you or the hammock. This will cause heat loss. I put in a couple inches of fudge factor for this.
blackbishop351
02-10-2007, 13:20
I am getting ready to build myself a hammock sock. I have a question for those who use one.
How big is the sock at it's widest point? What's the circumference?
Lol!! Have fun with that! The problem is that every person/hammock hangs differently, so it really has to be a custom job. You want the thing fitted pretty well so you have plenty of room for you plus underquilt etc., but you don't want TOO much room because that's more air you'll have to heat.
Here's what I did:
I hung my hammock, then made 1-foot measurements along my ridgeline starting at the foot end - the point where I wanted the sock to stop. I marked the measurements with little pieces of duct tape so I could locate them easily.
I got three 2-liter bottles (I drink a LOT of soda) to use as spacers. I put rolled-over duct tape loops on the bottles (sticky side out all the way around the tape).
I got in my hammock and got settled the way I'd be sleeping. Starting under the first length measurement (duct tape mark), I stuck the bottles to the bottom of the hammock, one to each side and one near center. I wrapped a cloth measuring tape around the whole thing - ridge, hammock, and bottles. I wrote down the girth measurement and the position along the ridge.
Move the bottles under the next mark (toward the head end), measure, and record. Repeat until the girth measurements start getting smaller - you can stop there.
After I had all those measurements, I saw that several were pretty linear so I just adjusted to make a straight line there - you don't have to do that though. I think I ended up with a couple of straight diagonals, then full-width past the widest point.
Then just get your material, put a drawstring in one end, fold it in half lengthwise, and mark out your measurements. I just used a basic inside seam ( I don't know the 'proper' term there) on the bottom.
Lol!! Have fun with that! The problem is that every person/hammock hangs differently, so it really has to be a custom job. You want the thing fitted pretty well so you have plenty of room for you plus underquilt etc., but you don't want TOO much room because that's more air you'll have to heat.
Here's what I did:
I hung my hammock, then made 1-foot measurements along my ridgeline starting at the foot end - the point where I wanted the sock to stop. I marked the measurements with little pieces of duct tape so I could locate them easily.
I got three 2-liter bottles (I drink a LOT of soda) to use as spacers. I put rolled-over duct tape loops on the bottles (sticky side out all the way around the tape).
I got in my hammock and got settled the way I'd be sleeping. Starting under the first length measurement (duct tape mark), I stuck the bottles to the bottom of the hammock, one to each side and one near center. I wrapped a cloth measuring tape around the whole thing - ridge, hammock, and bottles. I wrote down the girth measurement and the position along the ridge.
Move the bottles under the next mark (toward the head end), measure, and record. Repeat until the girth measurements start getting smaller - you can stop there.
After I had all those measurements, I saw that several were pretty linear so I just adjusted to make a straight line there - you don't have to do that though. I think I ended up with a couple of straight diagonals, then full-width past the widest point.
Then just get your material, put a drawstring in one end, fold it in half lengthwise, and mark out your measurements. I just used a basic inside seam ( I don't know the 'proper' term there) on the bottom.
And I thought I was over engineering the thing.:confused:
A really easy way would be to hang some cheap fabric from the ridgeline, get in, have someone mark or pin the bottom, and get out and measure it. Easy custom job. You could always guess and pin it yourself, then test and adjust it.
Another side note. If you use more than one piece for the circumference, it helps to hold it open. Risk and Jeff have some info on this on the sites.
Just Jeff
02-10-2007, 13:57
I think mine was ~85" around...it's probably on my site. One thing I'm going to do differently on my next one, though...I measured the circumference around the feet just like normal. But when I really get diagonal, that didn't leave enough room and my feet push against the sock (depending on which hammock I'm using...the wider/flatter ones have this problem). So for my next one, the insert in the bottom will be asym to give my head and feet more room.
Might work better if you have a partner. Lay in the hammock you're going to use, exactly how you lay in it when you sleep in the various positions, and have the partner measure. That's a more accurate measurement for the widest circumference you'll need.
blackbishop351
02-10-2007, 13:59
I think mine was ~85" around...it's probably on my site. One thing I'm going to do differently on my next one, though...I measured the circumference around the feet just like normal. But when I really get diagonal, that didn't leave enough room and my feet push against the sock (depending on which hammock I'm using...the wider/flatter ones have this problem). So for my next one, the insert in the bottom will be asym to give my head and feet more room.
Might work better if you have a partner. Lay in the hammock you're going to use, exactly how you lay in it when you sleep in the various positions, and have the partner measure. That's a more accurate measurement for the widest circumference you'll need.
Yeah - having a helper would definitely make things easier. It took me quite a while to get the measuring done by myself.
headchange4u
02-10-2007, 17:59
I am making this sock for my zHammock. I am using some scrap material that I have lying around to put one together. I am using a forest green 1.1oz DWR on the bottom for splash protection and a tan 1.9oz untreated on the top for breathability and gray 1.1 oz silnylon on each end for water protection. I only have a 50"x80" piece of 1.1oz DWR ripstop to work with but I have plenty of the untreated. I'm getting low on silnylon so I want to use it sparingly.
blackbishop351
02-10-2007, 18:24
I am making this sock for my zHammock. I am using some scrap material that I have lying around to put one together. I am using a forest green 1.1oz DWR on the bottom for splash protection and a tan 1.9oz untreated on the top for breathability and gray 1.1 oz silnylon on each end for water protection. I only have a 50"x80" piece of 1.1oz DWR ripstop to work with but I have plenty of the untreated. I'm getting low on silnylon so I want to use it sparingly.
My take on using untreated for these is that they might breathe TOO much. Not enough air blockage, which is what you're going for. JMO.
I think the way I'd do it is this: seam your piece of DWR and a 50"x80" piece of untreated together to make a tube. Put it around your hammock so it's about centered. Pin underneath (or have a helper do it) for girth. Make sure you leave enough room for quilt, etc. Gauge the end sizes for the sil 'caps' so you don't have to use any extra. Cut rectangular pieces of sil for those, then seam them onto the tube at each end. Repeat the pinning process. Mark lines on the whole thing where you pinned, then cut and seam. Should work pretty well and not use up too much extra material.
headchange4u
02-10-2007, 18:40
It's the same 1.9oz I used for my HH top cover and it does well in blocking air. I think that's due to the material is a little heavier than the 1.1oz I normally use.
I did a test with sil, uncoated, and DWR. I put the material on a fan set on high, then my face on the other side. I could not tell a noticable difference.
My tarp is usually set pretty low and blocking all of the wind. I think the socks man purpose is to trap in your heat, vs blocking the wind.
But to each physics guy his own.
slowhike
02-11-2007, 07:34
if a person used a light weight non-treated nylon for a sock & decided later that it wasn't as wind resistant as they wanted, they could simply spray it w/ dwr from a can.
Just Jeff
02-11-2007, 07:53
The sock makes a big difference by blocking the wind underneath the hammock...providing a big layer of dead air between the air currents and your insulation to slow convective loss. It also traps heat from rising.
But I agree that aside from breathability issues with sil there's probably not much difference between the fabrics for this purpose. But I can tell a difference between the untreated fabrics in my homemade hammocks and the HH...I can feel the air coming through my homemade hammocks. But a sock isn't stretching under force like a hammock is.
I think the size of tarp comes into play on the amount of wind. On mine, you cannot see any of the hammock of hammock sock from the side. I think it blocks the air currents that circulate underneath.
Maybe a scientific test with wind and temp sensors is in order.
Edit: I think it provides good coverage from the wind that always seems to come in the head or foot end on my tarp.