Any brave souls going to experiment with Vapor Barriers this winter?

[BillyBob58]

Yay! A VB discussion! My comments in red.

Not a newlywed yet. 28 more days to go, but I have been busy with this wedding and TRUST ME, I would much rather be talking gear than doing that. lol

I get back from the honeymoon on January 23rd and hopefully I can start cranking out more videos then, vapor barriers are at the top of that list.


Fronkey

Looking forward to that!

Please comment on this (I plan to keep my head/breathing outside the VB/insulation in a HUG style window sheer enclosure:
During previous experiments with a GG pad in the low 20F range, I found that a flannel (cotton) pillowcase over my GG pad absorbed and stored the condensation moisture nicely while my poly/synthetic insulation stayed dry to the touch (I didn't weigh it). So my moisture passed thru synthetic insulation, condensed at the pad, and was absorbed by the cotton.

What I had in mind to try next (at home) is a layered approach - an thin insulating layer next to the skin (thin lambs wool sweater and poly long johns/socks), flannel/cotton sheet outside that to absorb condensation, the VB outside that and then the TQ/UQ insulation.

That will probably work, it's all an experiment. But what I am thinking is: why a 2nd flannel cotton layer to absorb condensation/sweat? To my way of thinking- though I am still learning- whatever is inside the VB is sacrificed as far as insulation goes. It's only- or main anyway- function is decreasing the unpleasant(to me) feeling of plastics or coatings against my skin. I figure it won't provide much if any insulation since it will very likely end up wet. One thin layer against my skin will accomplish that. Of course, I can't say that cotton layer won't increase comfort even more. It might! Especially if weight is not a concern. But if backpacking in for several days or more, that cotton layer is going to get wet and won't be drying out. I don't think it will make you cold if it is under the VB and evaporative cooling is blocked, but it will get heavy. Might be comfy though!

VB thoughts/questions:
Does it really have to be a 100% barrier? Would a dry ducks rain suit work (limited breathablity)?
It apparently does not have to be 100%. Even Stephenson's Warmlite(makers of VB clothing) says that Goretex etc will function as a VB due to their decreased breathability. I have always had a hard time believing this. But I have read of folks using breathable rain gear as a VB with OK results. And when I set my PB at 6F last January using VBs, I had a thin layer long johns on my legs covered by my WPB rain pants covered by all my other insulation. (100% VBs for shirt and socks though) I guess it worked OK, seemed to. I suppose that even if you only decrease(as opposed to stop) the evaporative cooling and flow of vapor and sweat into the insulation, that is better than nothing.

Can the VB be a large commercial trashbag or is a suit (jacket/pants/socks) better? I guess the micro-climate is smaller with a suit but how much difference does that make?
I prefer the clothing for what you said about small micro-climate (possibly, I don't really know how much dif it makes) but mainly for when it comes time to get out of a VB bag/liner. That is when you will quickly learn how much impact evaporative cooling can have, when you leave a warm quilt and step into the cold with damp long johns! Of course, you probably have to come out of the VB clothing sooner or later unless it is bitter cold and you are going to hike in them. But I'd rather wait for the sun to come up before stepping out of the VBs into the cold! But a sealed off trash bag or bag liner will def work. They have been used for decades. There may even be some advantage to that I am unaware of.

If bag, what about a mylar bag or SOL bivy?
If it does not breath it will work as a VB. Mylar is what I have used for years with my SOL space blanket in my HHSS or inside a PeaPod, makes a fine VB. Of course, if it is just a space blanket under you, it will keep moisture from heading down into your quilts, but won't be as efficient as a bag or clothing for keeping moisture from evaporating of your back when you move off of your back or from side to side.


Stephenson's VBs looks interesting at $30 for the shirt and $8 socks - what material is on the inside? How do you clean it/ how much cleaning is require?
It is Fuzzystuff. I love it! It makes them very comfy VBs for me, more comfort than I used to get with a thin layer of LJs. I wear that right against my skin. I hate to admit it, but I have never cleaned mine. I was just thinking the other day that I really should wash them. But they don't seem to need it, no odor at all. NONE. They always seem to dry very quickly. That is, if they do get damp. Most of the time I can not even tell they are damp, unless I work up a sweat.

P.S. It rarely gets below 20F here so this is just fun/interesting experimentation for me (the wife questions the sanity in it), and Shug's -40F record is also safe from me ever challenging it:>)

Same here, it's all just for fun! A day below 20F is pretty rare for me. But I have found I can use less insulation for hiking or especially sleeping when it is in the 20s-40s, and keep my insulation drier, way drier.

I haven't used VBs before, but I'm definitely planning to do some experimenting this winter. I have a bunch of boy scouts we are taking into the mountains this winter and so I'll teach them a little about the concept before we go....a group experiment of sorts. I'm a little nervous that the scouts will be...scouts, so the first time or two I'll have some back up options for the 2am wimpering from the tents around me.
@BillyBob58 - Does the Stephenson's Warmlite clothing help with the moist feeling mentioned by others when using a VB?

Yes, by all means have some backup! Until you know that you and those scouts really do understand this VB theory, be prepared to go the conventional route with lots of insulation. And even backup insulation in case you do the VB thing bassackwards! People do that, definite learning curve. Caution! If you do the VBs wrong, you will end up with wet insulation and freeze!

Just remember: except for the thin synthetic or wool comfort layer underware next to your skin(or, just Fuzzystuff VB against your skin) ALL INSULATION OUTSIDE of the VB. Any insulation inside a VB will likely get wet and COLD! Insulation outside a VB will keep you very toasty and stay dry for long trips if you keep the rain off!

Unless I actually mess up and work up a sweat while working in the yard, hiking real hard, or theoretically sleeping in way to much insulation and failing to vent- thus sweating- I never know I have the SWL fuzzystuff VB clothing on, . Many a time I have sat around in the house in winter watching TV. Thermostat at maybe 68-70F. Nothing else as a shirt, just the SWL VB shirt. When I am doing that I never notice any moist feeling. I have with other unlined VB stuff, even with thin long johns. And I will notice with this if I actually sweat, but mostly not at all.

One time I was day hiking hard, in a hurry to get home, experimenting with my VB shirt in the 40s or 50s maybe warmer. Just playing around. I can't remember what my outer layer was, maybe just a thick cotton shirt or a very light fleece layer. I knew I need to open up the outer shirt and even unzip the VB shirt to vent, I was heating up and I could tell I was sweating. But I said to heck with it and just kept making good time up steep hills. I put out a lot of sweat inside that VB. When I got back to my truck, I tool the bone dry outer layer off and unzipped the VB shirt and cooled and dried off pretty quick. Now, that is a stupid way to do things and I would never actually do that on a real backcountry trip. If I hiked with a VB, I would aggressively vent it. Still, bottom line, my shirt- my actual insulation- was bone dry. Then I thought of all of the hikes I have been on in my life up a steep hill with a heavy pack, with no VB but despite my best effort I ended up sweating. A lot sometimes, especially on my back against the pack. And I thought about where that sweat normally goes- obviously into my insulation. Or even if not obviously sweating: all day long the vapor is leaving my skin, and HOPEFULLY passing therough my insulation to the outside. But does it ball pass through without condensing inside my insulation? In the case of that heavy sweating that day hiking- I remember thinking: would I rather have all of this sweat - which was the result of me being careless- against my wet skin and uncomfortable for a few minutes? Or soaking my shirt? Unless it is warm weather, that is an easy decision for me.

I wish Y'all good luck on your experimentation! Keep us posted about success or failure!

[BillyBob58]

I have a summer UQ made out of Insultex that I use as a VB on the inside of my winter quilt. I've had good succcess with it. I don't sweat very much so moisture has not been a problem. I also use plastic bags on my feet in my boots and find they make a difference in warmth. It seem counter-intuitive at first but as per VB discussions I've seen, it seems to make sense.

It is counter intuitive, isn't it?

[Floridahanger]

I don't believe you would want any layers inside the VB. The mircoclimate created by the VB needs to be simple. Your body will regulate how much sweat is made by how much leaves the skin. If you have fabric to wick it away, your body will create more. This is why FireFighter suites are made the way they are, even for Summer in hot fire season. Their suites are made to make you sweat. The sweating is to cool you.

If you have no fabric to wick away sweat, your body will slow the production of sweat. Just don't have too much insulation outside the VB to overheat yourself inside the microclimate.

If you want a limited body VB(I don't know how porous it is), you may want to look into painters suits made of Tyvek. They are inexpensive at Lowes or Home Depot and have the option of hooded or not.

I hope this may help in the testing and experimenting of VB's for hiking and cold weather sleeping.

[Jayson]

I will again be using VBL's this winter. Have always used bags on my feet and last winter i used a "Gold's Gym" sweat suit as an almost full body layer. It wasnt robust enough to use again but from memory i needed much less clothes during the day and used a standard fill HG 0* UQ with 2 layers of jogging suit fleece down to -39*C top was a 2 20*bags layered. Only my face was cold. This year will be silnylon rain suit, hopefully it is tougher.

[twandawg85]

I'll be testing my PEF (basically insultex) UQ in my yard when I'm done making it. I'm relatively new to hanging in cold weather. And I'm starting out with vapor barrier insulation.

From everything I have read. It takes less to stay warm, but needs more knowledge to use properly. I'm a thinker, so I would much rather carry less and know how to use it properly.

[BillyBob58]

I will again be using VBL's this winter. Have always used bags on my feet and last winter i used a "Gold's Gym" sweat suit as an almost full body layer. It wasnt robust enough to use again but from memory i needed much less clothes during the day and used a standard fill HG 0* UQ with 2 layers of jogging suit fleece down to -39*C top was a 2 20*bags layered. Only my face was cold. This year will be silnylon rain suit, hopefully it is tougher.

Well, those are pretty spectacular results if you ask me. I imagine most people who would be using a 0F rated HG would be wearing about the equivalent of 2 layers of fleece when pushing it to it's limits. But you are saying you were warm enough about 40 degrees lower than the ratings, correct? I'm trying to figure out what could account for that other than the VBs? The fleece would buy you a few degrees, even compressed under your weight, but how much? Seems like I have often seem claims for VBs adding anywhere from 15 to 20+*F of warmth, plus the benefits of keeping the insulation drier. But looks like you may have got more than that out of it. Do you think you would be warm with that UQ at minus 20F just adding 2 layers of fleece? Maybe. After all, you are Canadian! But if not, then you got more than the nornally anticipated boost from your VB.

I'll be testing my PEF (basically insultex) UQ in my yard when I'm done making it. I'm relatively new to hanging in cold weather. And I'm starting out with vapor barrier insulation.

From everything I have read. It takes less to stay warm, but needs more knowledge to use properly. I'm a thinker, so I would much rather carry less and know how to use it properly.

Apparently Insultex is not very breathable and so functions as a VB, from what folks say. As far as the proper knowledge to use VBs properly, it really comes down to just a couple of simple rules. But apparently over the years there have been lots of folks trying VBs who did not appreciate these rules and end up getting some really crappy- maybe even dangerous- results.

#1. A VB is to be used next to the skin or extremely close to the skin. ( a very thin layer of something like synthetic long johns serves to decrease the discomfort of very high humidity and water proof fabric against your skin, but not so much for insulation) If a VB is kept warm(next to your body) there should be no condensation, only very high humidity. Vapor condenses into liquid on cold surfaces, not warm. (I'm talking about condensation, not sweat, different subject)
2: A different way of stating #1: there should be no insulation between the skin and VB unless you want that insulation to get wet for some strange reason. Because it almost certainly will be exposed to very high humidity snd at least become slightly damp, and may well become soaked.
3: If you want to avoid sweat, a different subject than condensation, you are probably going to need less insulation at a given temp and probably will need to pay attention and vent quicker than you used to. You must avoid over heating. With out VBs, it is easy to be very toasty and sweat but not really know it. The sweat is wicked away from your skin and into your insulation. Hopefully it will some how become vapor again and float right out of your insulation by way of evaporation, although that leads to the main function of sweat: evaporative cooling. If it doesn't do that, then you have wet insulation. But if you over heat and sweat using a VB, that sweat is not going anywhere: it stays right next to your skin. Which is not all that comfy. But, no matter how much sweat, it is not cold. It does not get into your insulation. Many of us know the results of- despite our best efforts- working up a sweat a few times on a long hike, and then stopping to rest. We often then find that our insulation isn't keeping us near as warm as it did before we worked up a sweat while wearing it.

So, as always, avoid sweating with or without VBs. It's just way more comfy that way. But if you do mess up and sweat while using a VB under insulation, it won't be near as big of a problem. It won't be fun, but it won't cause you to become hypothermic. Unless, of course, you mess up and sweat or even don't sweat but just put out normal amounts of vapor- while having a significant amount of your precious insulation underneath a VB. If that is the case, you are screwed and you are going to get very cold. Much needed insulation underneath a VB might kill you if you can't call it a night and go in the house. So, don't do that!

[BillyBob58]

BTW, just before writing that last post, I had put a VB shirt on with a cotton flannel shirt on over it, as I was about to go outside and do some light work. But I got distracted and sat down to write the post, inside temp 70F. With the flannel shirt on, in the time it took me to respond, I think I was a little to warm. I feel vey warm and a bit humid. Probably on the verge of sweating, but not quite. Now I am going outside to cool off. If I was staying in, and wanted to test the VB shirt, I would def remove the flannel shirt.

[Lamboy]

Do any of you guys have any pictures of your VB Shirts or Pants?

I figure a simple bag is good enough for your feet.

[oldpappy]

Do any of you guys have any pictures of your VB Shirts or Pants?

I figure a simple bag is good enough for your feet.

Here you go: http://warmlite.com/vapor-barrier-clothing

[Floridahanger]

Many folks do use plastic bags on their feet inside of their TQ or SB. It's better than tight wool socks because of the microclimate on each foot takes less energy to warm them and tight socks restrict blood flow, cooling the feet.

A good VB with correct knowledge of use is just as good as top shelf gear at a lower price, seems to me.