Originally Posted by OneClick
Your dang right he is! Good thinking on your part! A wet foot box, eh? Interesting! Looking forward to the write up!
Your dang right he is! Good thinking on your part! A wet foot box, eh? Interesting! Looking forward to the write up!
After spending a couple nights in cooler weather, I noticed the dampness all around the edge of my TQ footbox after a 19° night. Everything else was dry, but this always seems to be where to vapor exits. So I took this vapor barrier bag liner up to northern Michigan where I knew it would get some good use in the cold, snowy weather.
When the temp was forecast to hit 18° I put this into my TQ. Getting in was a lot easier than I imagined. I went to bed really early after being tired from snowshoeing and basically just bored after a fire. I slept from 8pm to about 4am. It was about 25° when I went to bed. My thermometer said 20° when I got up.
I was amazed! From start to finish, I never got too hot or even clammy. I expected as least a little, but no! I used my 20°+1 Hammockgear Burrow and light base layer clothing. I had a frost bib over my mouth to block moisture from my breath. Unfortunately it fell off at some point and got the neck area a little wet but not too bad.
It’s hard to describe, but I found this very comfortable. After 5 minutes of warming up it almost felt like I had an external heat source. It sort of felt like when you overexert yourself on a hot summer day, and your skin radiates heat even after you cool down. I don’t know how to describe it. But not too hot, certainly not cold, and not even clammy after 8 hours in this thing!
After getting out, I checked the vb liner first. This thing was bone dry inside and out!
My clothes were also totally dry!! Thin long john bottoms, thin ¼ zip shirt, Icebreaker midweight wool socks.
Then the top quilt, which had some wetness on the outside about half way down. That could have been from my breath or the 8 hours of spindrift blowing around ALL night. Icy sugary type of snow. I could even feel it hitting my face at certain points even though my tarp had good coverage.
When checking my hammock, I was disappointed to see the usual “oldschool freezer frost” on the foot end. The heat coming out of my UQ always produces this. But it had to be moist air from my body, right? So the vapor was coming from somewhere.
The only thing I can think to try differently is to put my body totally inside this liner. This time, I had it up to my armpits, so my neck, arms, and hands were inside the TQ. I didn’t think that would be enough to matter. Maybe this is an all-or-nothing game. I'm going back out in 2 weeks so I will try again if it's cold enough.
I had the liner pulled up to my arm pits so I could have free arms outside. I cheated, so that could have been the cause any apparent wetness.
Layered inside the TQ
Dampness on TQ in morning (hard to see)
Inside of vapor barrier liner - TOTALLY DRY!
The usual frost on my hammock. Always on each side of the foot end near the point. This is where the heat leaks out (impossible to stop even with a good setup and draft collars)
Well, how about that! Foot box dry? Apparently the theory is confirmed once again, and it worked at least as well as predicted.
Condensation on th outer shells and tarp does not have to come all from body vapor. More than once I have had this happen: the other day I had a cheap but large tarp all the way to the ground and with doors closed. I wentout the next morning to add my JRB GL 4 UQ, and literally got my cotton shirt soaked from the condensation on the inside of the tarp. Other times I have got things set up in winter, then gone back in the house until bed time, and come out to a frost covered UQ, TQ and tarp. So it happens. But how blocked was your exhaled breath? Unless well blocked, I would expect that to provide the largest amount of vapor for condensation. It can even get down to the foot end or up to the tarp.
But, all n all, this is a very interesting test you did! And obviously gave you some very positive results. Just wait until it is minus 15F! I'm sure your arms and upper body provided some available vapor. If you want your arms out, next time just add your rain gear up top.
Yeah I think putting any gear outside will get damp, even covered by a tarp. Or at least that clammy feel. Down or really any kind of fabric is like a sponge. So I'm feeling good about this. Plus, it was a steady 35-37F during the day with about 10" of snow on the ground so it was just moist in general.
The frost on my hammock isn't a huge deal since it can be knocked off. But the TQ...I gotta keep it DRY after last winters experience.
I really think this is a huge deal! I typically feel fine taking my 20 TQ for a forecast of 18F. But this time the thought never crossed my mind once getting in. I could tell this was adding some major temp rating.
It's just a simple tube of non-breathable nylon with drawstring at the top. Hint hint cottage manufacturers.
I sure am tickled that a few of you well respected folks- people respected here and known to be well experienced in cold and damp and card carrying and long term members of the breathable club- have been doing some experimenting with a VB approach for a year or two. And Y'all have been succeeding! Why does this tickle me? Because you guys are also providing evidence to the many that I might not be as much of stark raving lunatic as many may have assumed.After all, every one(except for lunatics of course) knows that if your stuff is not as breathable as possible, you are going to get wet and cold. And ESPECIALLY if it is above zero. But for years, I have been the odd man out going on about possible benefits of non breathable HHSSs and VB clothing, WEIRD!
But here you are, in a totally non breathable sack, at about 20F, warm and DRY. And after 8 hours, not even swimming in a pool of your own sweat and/or condensation. And though you have had issues- due to condensation inside your breathable gear- keeping insulation dry in the past, now it is bone dry. Even inside the VB was dry! Who would have ever thunk it! I mean, other than lunatics?Now, no doubt due to yours and others experiments, I have already noticed a reduction in welfare checks by authorities responding to calls from folks concerned about me.
OK, I am trying to be funny, but I really am pleased to see some folks other than me investigating this approach! So, keep it up and I hope it continues to be a benefit for you!
Oh yeah how could I forget to mention the VB socks!? Even though I was wearing very warm boots and it was rather warm in the 30s, I wore them. Because I knew either way I would be sweating in the boots, and sitting in camp with damp boots is downright painful. So I dealt with hot feet hiking but rewarded with DRY socks and boots when in camp. And more importantly, dry boots in the morning which only took a few seconds to warm up and feel great.
And like the bag liner, the VB socks were almost dry. On my feet that felt like they were sweating for hours. Amazing! My feet were damp feeling but dried off in seconds before putting on warm, dry socks.
Wet quilt again!!
I wish I had my vapor barrier liner to test this past weekend. I thought it would be too warm, but the weather guys screwed up as usual.
When I woke up I reached down to feel my TQ...again covered in wetness. I'm not sure if it's my breath or moisture from my body all night. I had a shirt over my face all night which was soaked, so I would assume that caught most/all of the breath. I wasn't overly warm or sweating at all; I used my 20° quilt set for consistent 25° temps both nights.
The wet area seems to be only on the TQ, from about my lower chest to knees. When I woke up to do some business at 5am I just wiped everything down with a towel. I'm not sure what else to do and why did this just start last winter after 7 years of hanging? I'll be sure to take the vapor barrier liner on every trip going forward this winter.
Ok even after starting this thread and following conversation, thinking and contemplating VBs still seem out of my wheel house. If I am going to purchase a fail proof vb sleeping bag liner what model should I go for?? Also, what if you happen to be a sweaty sleeper?? Last night I was sweaty in my normal comforter in my own bed. Does that mean vbs will make me miserable? Or does that mean they will save my life?? Haha so confusing! Just ordered a custom -20 TQ from ugq and I want to do some brutal winter stuff this year and laugh in the face of mother nature. Does anyone get me? If you had to make a pie chart how much of warmth goes to each piece of your setup? Also can you please submit a 1000 word essay on your favorite piece of winter camping gear? Of course I’m being a jack a$$ but winter camping got me like �������������� I hate it and I gd love it
Campmor has a VB bag liner for $27. Give it a try. If you're sweating anyway, you have nothing to lose. But you stand to gain up to 22 degrees of free warmth. Also, the theory is that once you reach 100% humidity insensible sweating will stop. if your sweating is related to a super high metabolism, then who knows. Try it, you might like it.
PS. the Emageddon..... it lives!
Hey, Bro, VBs are freaky, but I have grown increasingly fond of them since I started with VB socks in 1983, so well over 30 years of experimenting with them.
No one can answer how that will work out for you as far as sweat goes, especially if you over heat. If you over heat, you are going to sweat, period. But sounds like you are like me: you sweat any way. So now the question is: where would you rather that sweat end up? Inside the VB next to your skin, or in your down insulation decreasing loft and warmth night after night?
I prefer VB clothing from Stephenson's Warmlite. Other folks like VB liners just for their bags/quilts. Some folks hate VBs period. I have no clue where you might fall on that scale, but the wonderful thing is it makes for a fun, cheap and safe experiment to find out. In your back yard or some drive in camp ground where you have a safe bail out. Just get a big old waterproof garbage or leaf bag, and wearing some polyester or wool long johns(and probably nothing else, because these clothes might get damp), and put it in your bag, then put yourself in the liner bag. Or, wear some poorly breathable or NON breathable rain gear close to your skin and under most of your insulation. (but warning: be prepared to use less insulation than normal for a given temp, or risk over heating!) Then, see how it goes. Maybe you will like it, or maybe you will hate it. But you can safely and cheaply find out for yourself.
Just to make sure you don't end up cold and wet rather than warm and dry- or at least end up pretty dry, with your outside the VB insulation WAY dry- it is probably best to only wear something thin and quick drying inside the VB, next to your skin. But anything on your skin's side of the VB is at risk of getting wet. But done correctly, anything on the other side of the VB should be drier(and loftier) than you could ever hope for. As you get more skilled, you might fin you can wear something slightly warmer under the VB and still not get wet, which might be more convenient.
Good luck, and have fun!
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