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dejoha
12-23-2010, 18:44
I was asked by ChrisH (http://www.hammockforums.net/forum/member.php?u=10210) to make up a simple illustration about vapor barrier liners (VBL) in an effort to help explain how they work and when to use them. I've experimented with VBL's in the past with good results (and some real disasters!), but the real experts are those who've successfully used them in the field. I contacted sclittlefield (http://www.hammockforums.net/forum/member.php?u=2054), one resident expert on VBL's in the forums, who helped frame a lot of my thoughts. I also read and researched several articles, but the one article I found that did the best job is from the long-distance hiking guru, Andrew Skurka. Skurka's article "Vapor Barrier Liners: What they are, how they work, and when to use them (http://bit.ly/gM1jhF)" was perfect, and I think his real-world experience is a must-read if you are interested in VBL's.

My illustration and notes hopefully explain some of the basics, and perhaps add a visual reference to other, more thorough articles like Skurka's.

The main points I've gleaned from personal experience and from what I've read is this:


VBL's work best when it is cold (<= 40įF/5įC).
A VBL should be close to and completely surround your skin to effectively create the micro-climate your body needs to stop perspiring and maintain its temperature. For comfort (e.g., to eliminate a clammy feel), you can wear a base layer before the VBL.
VBL's are critical for long-term winter camping, but can be effective for overnight trips as well


From my reading, VBL's receive criticism because of excessive moisture build-up. Proponents argue that the presence of moisture build-up is an indication that the VBL was used incorrectly.

A VBL can effectively "trap" the insensible moisture around your body to create a micro-climate where body's hydration and temperature are then regulated and stabilized. Once the micro-climate is stabilized, the body stops transmitting insensible moisture.

That's Great, But How Does That Apply To Hammocks?

A VBL can be used in a hammock very easily, as either a bag or quilt liner, or as Skurka recommends, as part of a layered clothing system.

VBL's should not be used on the outside of insulation (either under quilts or top quilts) because moisture will eventually build up inside the quilts and will collapse the insulation. Underquilts are less of an issue since water vapor tends to rise upward.

Some pads (e.g., closed-cell foam) create VBL's since they don't breathe, however, they only provide a VBL on one side of your body, which can create irregularities with your body's thermoregulation.

You can use any non-breathable material to create a VBL: plastic bags, sil-nylon, coated nylon or polyester, etc. The real "trick" to a VBL is to make sure your body temperature is properly regulated. Skurka used VBL's while hiking, backpacking, and snowshoeing, proving that VBL's can be used during moderate exertions.

Anyway, I hope the illustration helps. Again, I would refer you to Skurka's article, which I think does a much better job in explaining VBL's.

http://www.hammockforums.net/forum/attachment.php?attachmentid=16848&stc=1&d=1293145190

whayneneal
12-23-2010, 21:50
I have recently purchased an under quilt protector from 2q2z and I'm in the process of trying to decide what to use as a vapor barrier. I must admit I'm somewhat skeptical having no experience with one. I don't like the thought of waking up soaking wet in the middle of winter.:( Thanks for the information. This was helpful.

I think I'm going to try an Adventure Medical Kits S.O.L. Thermal Bivvy with mid/heavy weight base layer.

ChrisH
12-23-2010, 22:24
Awesome illustration dejoha! Thanks so much, it makes it much easier for us noobs to understand. Really appreciate all the time and effort that you have put into this!

MedicineMan
12-23-2010, 22:38
Back in my ground dweller years, when backpacking in serious cold I'd carry a vapor barrier...it doubled as my pack liner and was long enough for a complete me to get into it. It was a pain sometimes loading the single cavity frameless pack (a Mithril by Moonbowgear) because of the excessssssssss material this pack liner had. That said, it was sil-nyl and as a true vapor barrier was/is designed to go directly against the skin, e.g. a naked body. With this method another potential 20F could be had and NO moisture would get on clothes or inside the sleeping bag because 1. it was eliminated from formation by stopping the process of insensitive sweating and 2. because this vapor barrier being sil-nylon was impervious to moisture.
The only B%^&@ about using it was in the morning....picture yourself waking up in a very very warm VBL that is also moist and having to climb out of it naked at anywhere from -8F to 10F !!!!
Of course you would transition from this VBL as FAST as humanly possible.
This pack liner therefore performed several functions-pack liner, entire body VBL (I would cinch it around the neck and have balaclava on the head, and emergency bivy...not bad for 4+ ounces.
I've not used it since 'evolving' but now that the subject has come up I might dig it out of the reserve kit pile.

Redoleary
12-24-2010, 07:34
Great illustration, and information. Thanks for that.

Bradley
12-24-2010, 08:20
I seems counterintuative to me . . . :confused:

Just Jeff
12-24-2010, 08:30
Science often seems counterintuitive, and as with any piece of gear, VBLs only work well within a defined set of conditions. Just as you wouldn't say a winter quilt doesn't work well b/c it doesn't give good results in summer, a VBL will only give good results when used correctly.

Great illustration, dejoha!

keys?
12-24-2010, 15:34
Wow! This makes so much more sense to me now than it ever has! Thanks for your illustration and link to that article. Now we just need someone to make/market a VBL union suit with pit/crotch zips...Dutch?

Danalex
12-24-2010, 15:46
Excellent information, thanks!

Turtle Feet
12-24-2010, 15:58
Is Insultex considered a vapor barrier?

OutandBack
12-25-2010, 02:22
Nice writeup, thank you

BillyBob58
12-25-2010, 08:50
Is Insultex considered a vapor barrier?

Seems to be some dif opinions on and experiences with that. I think the manufacturer claims it is breathable.

gargoyle
12-25-2010, 09:20
I've never played with a VBL. Sounds clammy and wet. But I see the point and purpose. In the right conditions it would make sense.
Dejoha, excellent work as usual.

How about a tyvek suit? Or is tyvek considered too breathable? (never breathed well when I wore one)

http://www.isesusa.com/images/photos%20for%20brochure/---students_with_tyvek_suits.jpg

OutandBack
12-25-2010, 11:23
tyvek

Exactly what I was thinking.

In my type of winter camping, usually 3 days 2 nights I have never experienced a down failure from excessive moisture build up. Maybe I don't sweat very much when sleeping.

If I was planning an extended winter stay I think I would try the tyvek suit.

wisenber
12-25-2010, 12:21
After reading this, I had to go out and try a ghetto VB solution. My GT ATHH that I use in Winter is PU coated, so the entire hammock is a VB between me and my lower insulation. I took a kitchen trash bag and punched a head hole and arms holes into it. Under the kitchen bag, I wore a thin synthetic t-shirt. Over it, I wore a fleece top. On my leg, I wore Smartwool long underwear and my rain pants.
For top insulation, I used one of the sportmans' reflective blankets and a thin CS BPL TQ. Headwear was just a neofleece balaclave and a BPL hood.

Long story short, it was in the upper 30's F when I turned in, and I was roasting. Fast forward to 4 am ( I must have slept through Santa's visit) and I was cool and clammy all over. Somehow, there was quite a bit of condensation under the space blanket I had on top even with all of the VB stuff. My guess is that since I had neglected to put bags on my feet and my arms were not enclosed in a VB, I probably did not do a very good VB job. On top of that, temps only fell into the upper 20's.

FWIW, that BPL TQ usually only gets me into the lower 50's before I get cold. So by all rights, the VB did buy me 20 degrees more than I would have normally had.

I've ordered one of the WarmLite VB shirts. I figure closing up the arms in addition to the torso will make for better results. I also think the colder and drier it is the more you'll get out of it. (Upper 20's is probably on the upper end of usefulness. Colder would be better.)

All in all, it's a pretty good solution to not only stay warm and remain better hydrated but also keep your insulation from wetting as the dew point moves closer to your body (read inside you insulation) in colder temps.

Danalex
12-25-2010, 12:23
Yeah, that suit is cheap and pretty convenient unless you made a bag liner out of it but you'd have to seal the edge with a zipper so getting in and out is a pain.

wisenber
12-25-2010, 12:27
tyvek

Exactly what I was thinking.

In my type of winter camping, usually 3 days 2 nights I have never experienced a down failure from excessive moisture build up. Maybe I don't sweat very much when sleeping.

If I was planning an extended winter stay I think I would try the tyvek suit.

Tyvek, Gore-Tex and eVent do breath too much for a good VB. I've gone to bed in a wet merino top and a breathable jacket over top to awaken to a dry merino top. I've also dried socks this way. The down side (no pun intended) is that the moisture from the socks and top escaped not only the jacket but also into my down. If the dew point is high enough, that moisture will pass through the down and escape. If the dew point is lower, that moisture becomes trapped in the down.

I think VB is best probably in the teens or below. Above that, the dew point tends to be on the outside of your insulation. Teens and below will put the dew point closer to your body which can be inside your insulation.

BillyBob58
12-25-2010, 14:56
.................
For top insulation, I used one of the sportmans' reflective blankets and a thin CS BPL TQ. Headwear was just a neofleece balaclave and a BPL hood.

Long story short, it was in the upper 30's F when I turned in, and I was roasting. Fast forward to 4 am ( I must have slept through Santa's visit) and I was cool and clammy all over. Somehow, there was quite a bit of condensation under the space blanket I had on top even with all of the VB stuff. My guess is that since I had neglected to put bags on my feet and my arms were not enclosed in a VB, I probably did not do a very good VB job. On top of that, temps only fell into the upper 20's.

FWIW, that BPL TQ usually only gets me into the lower 50's before I get cold. So by all rights, the VB did buy me 20 degrees more than I would have normally had.

I've ordered one of the WarmLite VB shirts. I figure closing up the arms in addition to the torso will make for better results. I also think the colder and drier it is the more you'll get out of it. (Upper 20's is probably on the upper end of usefulness. Colder would be better.)

All in all, it's a pretty good solution to not only stay warm and remain better hydrated but also keep your insulation from wetting as the dew point moves closer to your body (read inside you insulation) in colder temps.

Looks like spectacular success to me, way warmer than you would have been normally, eh? And all of that moisture that condensed on the refl. blanket: curious as to why it condensed there rather than all inside the garbage bags? Maybe your theory why is correct. And what kind of rain gear, maybe it did not stop the vapor?

But that always leaves the question: had it not condensed on the ref. blanket, would it have condensed some where else? Maybe in the outer layers of the insulation? Also, had it not condensed on the ref. blanket, would it have then provided some evaporative cooling to your skin and/or insulation?

I always expect to be clammy, though hopefully not cool, when using VBs(exception: space blanket in a HHSS or PeaPod). This tells me it is working as planned. And it only gets damp, and nothing more unless I over heat and actually sweat. This clamminess freaked me out the 1st few times I felt it, I thought I was wet. And I was, but only my skin and innermost synthetic layer. But this dampness was blocked from causing evaporation and cooling. This is not the best feeling in the world, but is for sure warmer. So, wet(clammy, damp) but warmer. I always try to wear the absolutely thinnest layer I have between skin and VB.

For an impressive demonstration of the effectiveness of the bodies evaporative cooling ability, try a test. Put a vapor barrior on in some cold temps. Leave on a while, and avoid sweating. Then, snatch that little thin layer of WP nylon off of your torso or feet. Get ready to feel a rapid and very noticeable drop in skin temp! It will get your attention for however long it takes that dampness to evaporate. It will take a significant amount of body heat with it as it evaporates.

I ahd a buddy whose feet were freezing while fishing in winter, one Nov in the snowy AZ mountains. He borrowed my VB socks, put them under his thick socks. Within a short time, his feet were warm.

I've been thinking about one of those Warmlite shirts and pants for a long time. Please let me know how you like it(or why you don't!

wisenber
12-25-2010, 21:39
BillyBob58, I actually was pretty impressed that a 13 oz synthetic TQ and a sportman's blanket could keep me fairly comfortable into the upper 20's. (The pants I used were Mountain Hardware Conduit..breathable but not all that breathable.) The kitchen bag with a head hole and arm holes probably did not make that great of a seal around my torso. That and forgetting to do anything VB on my feet probably caused the condensation. (If I had to guess, there were maybe 3-4 ounces on the inside of the top space blanket.)

While some just go with minimal clothing and a VB bag liner, I prefer VB clothing. With VB clothing, I should get a better seal and I can still put other items of clothing packed on over top of the VB layer if needed. I know I can pile my clothing around the outside of a VB bag, but wearing a fleece jacket is probably going to insulate more than just piling it on my TQ.

Oh, I did "place an order" with Warmlite, but for them that just means they will call or email you to discuss what it is that you actually wanted. I think the socks and shirt would be the best option from them. I figure I can get surgical gloves for hand VB, and those rain pants are probably VB enough to reduce the amount of insensible perspiration from my legs.

I really do like the advantages of VB in Winter conditions. Not having to worry about keeping you insulation dry from the inside might allow the use of a non-breathable weathershield on top of a TQ for even better moisture control. Of course a "bonus" 20 degrees of insulation is not too shabby either!

BillyBob58
12-26-2010, 00:11
I agree, high 20s from a 13 oz syn TQ and extra 20 plus degrees over normal is not too shabby, not to forget dry insulation and all for a small amount of weight. And if rain gear provides the VB, the extra weight is zero.

Ever tried a VB inside the bottom of a Pea Pod? Or what about that Warmlight VB clothing serving as a VB for top and bottom in a PeaPod?`

MedicineMan
12-26-2010, 00:33
look for wrestling workout weightloss suits...some are el cheapo plastic and affordable---attach a Warmlite name and cha ching cha ching....for the feet/hands use bread bags.
Most people these days want breathable rain gear that negates use as true VBL-hmmm unless you wear it inside out

BillyBob58
12-26-2010, 11:41
look for wrestling workout weightloss suits...some are el cheapo plastic and affordable---attach a Warmlite name and cha ching cha ching....for the feet/hands use bread bags.
Most people these days want breathable rain gear that negates use as true VBL-hmmm unless you wear it inside out
That is true, no need to spend many $ to gain VB benefits. The Warmlite gear has some sort of lining (Fuzztstuff?) that might be nice rather than wearing a layer of thin long johns, and the fit might be an advantage. I don't know what the cost might be though, maybe too much.

I think they also have some rain gear intended to see dbl duty as a VB.

When my only need is to block vapor to an under hanging layer such as a HHSS or PeaPod, a $3 space blanket has, on and off for several years now, always got the job done. And maybe even reflects some heat back to me. I often have wondered if the instant warmth I always feel when adding the sp.bl. is the blocking of radiant heat, or simply the VB effect.

Trooper
12-26-2010, 11:42
Would a Gore-tex jacket inside of a sleeping bag or TQ create a vapor barrier?

From what I'm reading Gore-tex works best with a warm body inside and cold temps outside. But if a person wore the jacket inside of an insulating layer, would cause the Gore-tex to not breath.

BillyBob58
12-26-2010, 12:06
[quote=Trooper;376069]

error some how posted same post twice

BillyBob58
12-26-2010, 12:13
Would a Gore-tex jacket inside of a sleeping bag or TQ create a vapor barrier?

From what I'm reading Gore-tex works best with a warm body inside and cold temps outside. But if a person wore the jacket inside of an insulating layer, would cause the Gore-tex to not breath.

Supposedly it will work as a VB. Ironically, even the VB manufacturers warmlite says it will, because they say the stuff does not really breath well enough to keep it from functioning as a VB.

But IMHO, that is not fully correct to say the least. Because many many times over the years, I have had wet clothing completely dry out with various forms of WPB shells covering the wet or very damp layers. With Goretex and whatever the UL Gtx NF clone is, and Pertex Endurance. I have poured a cup of water or more into a Climashield jacket with an Endurance shell and let it sit a while, wrung it out and gone hiking. I have never been able to get water from a pouring faucette to go past this Endurance shell, so it is at least slightly water "proof". Yet after a light pace 1.6 mile hike ( in drizzling rain/sleet) it was bone dry.

Also, unless I exercise and actually work up a sweat, as opposed to just sitting around or very light exercise, I have never had things get damp in most of these jackets.

So I just don't see how such a shell could function as a good VB, though people say they do. I guess they might slow vapor down a bit, and maybe that is better than nothing.

Conversely, if I am in a true VB, or say old fashioned coated nylon rain gear, I never have any trouble feeling clammy, quickly. Even if just sitting around or laying in a sleeping bag. As folks report, you may even soon be actually slightly wet, even if you don't over heat. As long as I don't allow myself to over heat and sweat, I will only get so "wet", then moisture stops increasing. But it still often feels beyond clammy, and actually wet. For me, this is what I experience with true VBs. Thus evaporative cooling is stopped dead, and insulation on the other side of the VB is kept dry.

I never feel this sort of thing with my "breathable" rain gear. But people say it helps, so maybe it does.

But it won't hurt anything to experiment. If it doesn't work very well as a VB, then you are just back where you were with no VB in the 1st place.

Trooper
12-26-2010, 12:36
...whatever the UL Gtx NF clone is

That would be HyVent, which I have been extremely disappointed with. It is lighter than Gore-tex, but I've seen the fabric soak up water after a couple of hours.

I'll give the Gore-Tex jacket a try as a VB next time, as I already carry it. Might as well put that 360 grams to use.

wisenber
12-26-2010, 13:40
WPB layers are designed NOT to be a VB. They are designed to block water while letting vapor pass. They get wet on the inside when the rate of vapor generation exceeds the ability of the fabric to pass it. When you're in your hammock, you hopefully will not be generating a lot of sensible perspiration. The rate of insensible perspiration a body generates should be able to pass through a WPB fabric.
As BillyBob and I mentioned, hikers have been using WPB layers to dry clothing with the outward transport of vapor. This would seem to confirm that WPB is not VB. It's more like "vapor slower".

wisenber
12-26-2010, 14:49
After Medicineman's comment, I did a little digging. The wrestling suits appear to be heavy and made of vinyl. I found another one here (http://www.walmart.com/ip/Gold-s-Gym-Slimming-Suit-M-L/12546157?findingMethod=rr) that appears to be lighter weight and pretty cheap. I might go get one today. I figure I can wear that as a base layer (or wear something really thin next to skin) and put on some fleece pants and a fleece top over it. That still leaves my feet and hands. While bread bags will work for your feet, I think the Warmlite ones will be more practical and could be used in a layered system while hiking as well.

MedicineMan
12-26-2010, 16:29
Saw a guy today in the steam room post swim with the wrestling VBL suit. He said $11 for top and bottom. Was def vinyl ..didn't know the weight.

Tumbleweed
12-26-2010, 21:37
So, as I understand this thread, I could use:
First layer: lightweight silk underwear top & bottom,
second layer:driducks raingear top & bottom,
third layer: fleece pajamas,
then on feet: silk socks, bread bags, wool socks or down booties,
hands get thinnest possible gloves, surgical gloves, mittens.

Yeti under WBBB & TQ over all. Then just "ignore" the clammy feeling???

Would the driducks work differently if put on "inside-out" ?

Real curious about this thread.:):):)

MedicineMan
12-26-2010, 21:50
From my scant true knowledge of VBL use, the impermeable layer goes against the skin directly so bread bags against skin and then silk socks, wool socks, booties in that order.
In your first,second,third layer I didn't see a true VBL listed.
I'm wondering if in the James Bond movie 'Goldfinger' was the paint a VBL?

zukiguy
12-26-2010, 21:57
I've never seen the inside of the DriDucks raingear but my friend's poncho is kind of "fuzzy" on the inside. Are the raingear pants/jacket the same? If so, this wouldn't seem to be too uncomfortable against the skin. This sounds similar to the warmlite "fuzzy stuff".

I've been going around and around with my raingear. If these DriDucks would work as a passable VB as well as raingear/windbreaker that may entice me to pick up a set.

wisenber
12-26-2010, 22:44
So, as I understand this thread, I could use:
First layer: lightweight silk underwear top & bottom,
second layer:driducks raingear top & bottom,
third layer: fleece pajamas,
then on feet: silk socks, bread bags, wool socks or down booties,
hands get thinnest possible gloves, surgical gloves, mittens.

Yeti under WBBB & TQ over all. Then just "ignore" the clammy feeling???

Would the driducks work differently if put on "inside-out" ?

Real curious about this thread.:):):)

Driducks breathes too much. It will slow vapor transfer, but it is not a VB. You can probably skip the liner gloves as I don't believe there would be any thin enough to fit beneath a pair of VB gloves.

The clammy feeling is not pervasive with a good VB set up. You'll notice it from time to time, but it is not the same sort of "cold clammy" that most of us are accustomed to.
Some folks just use a VB bag liner that can be found at campmor.com in a reflective (http://www.campmor.com/outdoor /gear/Product___89033) or non-reflective (http://www.campmor.com/outdoor/gear/Product___41360) type. I've found that the vapor tend to pool more in these than with VB clothing.
If you have a silnylon Packa, you've already got a VB top. Just close all of the vents.

Personally, I'm looking for a lightweight sauna suit. Some might argue that it is single use; however, in SEVERELY cold weather, you could still keep the VB layers on through your hike and it will boost the insulation of your garments significantly. (Your head and your hands can still regulate heat at those temps.) Even if just used for sleeping, it "could" offset the weight in a couple of ways. The most obvious is that it can reduce your need for more insulation to the tune of about 20į F. The not so obvious weight savings would be that your TQ and UQ will not have gained the weight from the vapor being trapped inside. (This can add up to POUNDS saved.)
Finally, a VB layer is the best way to prevent frostbite. If your feet are in a VB sock surrounded by sealed in warm perspiration, they can't freeze.

Again, if you're out in temps above 20 F, the benefits are there but not as large. The colder it gets, the more benefit there is.

MedicineMan
12-26-2010, 23:23
I'd consider the weight of the sauna an incredible insurance policy since you can get 20F additional from it. I cannot see hiking it a VBL suit unless its in the negatives.
I think VBL bags have there place but the tighter it fits to the skin the better it will work. But speaking of VBL bags, this one from WM only weighs 4.5 ounces...that is a lot of warmth for that little extra weight:
http://www.westernmountaineering.com/index.cfm?section=Products&page=Accessories&viewpost=2&ContentId=44

MedicineMan
12-26-2010, 23:28
Walter, did you see this site yet?
http://www.rbhdesigns.com/category/172&cfid=12920913&cftoken=29817577/apparel.htm

wisenber
12-27-2010, 01:07
I'd consider the weight of the sauna an incredible insurance policy since you can get 20F additional from it. I cannot see hiking it a VBL suit unless its in the negatives.
I think VBL bags have there place but the tighter it fits to the skin the better it will work. But speaking of VBL bags, this one from WM only weighs 4.5 ounces...that is a lot of warmth for that little extra weight:
http://www.westernmountaineering.com/index.cfm?section=Products&page=Accessories&viewpost=2&ContentId=44

A VBL bag will definitely work. I do have a couple of problems with it. First, it's a bag. I dislike VBL bags for the same reason I choose a TQ over a sleeping bag.
second, I HATE getting out of those things in the morning (or middle of the night) in the cold while I'm wet. VB clothing at least lets me move around under my TQ, and I can swap for dry clothing "one section" at a time come morning.

wisenber
12-27-2010, 01:11
Walter, did you see this site yet?
http://www.rbhdesigns.com/category/172&cfid=12920913&cftoken=29817577/apparel.htm

Oh yeah I have. Those looks like they would work perfectly. That being said, the Stevens Warmlite stuff (http://warmlite.com/vapor-barrier-clothing) looks much cheaper for a fairly equivalent function. I'll probably get the Warmlite shirt and socks and see about some sauna pants. If I like the whole concept, I may look at the RBH pants as well.

Shug
12-27-2010, 10:19
I have done the VB thing and it for sure works. I have VB socks I used to use but I prefer to rise in the morning and not have to deal with changing out clothes.
For me the clamminess was not enjoyable .... the warmth was.
May re-visit it again but for backpacking I always seem to be able to bring enough to keep me pretty warm. At least I know that I wont perish....

slowhike
12-27-2010, 10:44
I have done the VB thing and it for sure works. I have VB socks I used to use but I prefer to rise in the morning and not have to deal with changing out clothes.
For me the clamminess was not enjoyable .... the warmth was.
May re-visit it again but for backpacking I always seem to be able to bring enough to keep me pretty warm. At least I know that I wont perish....

I'm pretty much in the same ball park as Shug on VBLs. But they do have their advantages.

wisenber
12-27-2010, 11:01
I have done the VB thing and it for sure works. I have VB socks I used to use but I prefer to rise in the morning and not have to deal with changing out clothes.
For me the clamminess was not enjoyable .... the warmth was.
May re-visit it again but for backpacking I always seem to be able to bring enough to keep me pretty warm. At least I know that I wont perish....

I hear ya on changing out clothes in the morning. I've been doing a bit of "backyard research" the past few days. Last night, I went out and bought one of those "sauna suits" and wore it over a layer of smartwool long johns and long sleeves top. On my feet, I put on a pair of nylon dress socks for liners, a plastic grocery bag and some thick wool socks.

I must say the results continue to impress me. The temps got down to about 21 F here at the global testing facility between two of my tulip poplars. I used a 3/4 UQ by Leigh and a JRB NS beneath my JRB tarp set up in "tent mode". I know, I know, you're saying to yourself ," Self, isn't that enough to get to 21 F anyway?" The answer is "yes". However, 21 F is at the lower boundary of the NS. I'm sure you've all have used gear toward the lower boundary before. While you're not freezing, you can definitely feel the lack of warmth. With the VB stuff on, I felt no chill whatsoever and felt that I could have gone at least 10 more degrees lower if not more.

Now here's the interesting part. On top of the added warmth, I checked my NS when I got up this morning. You know the way a TQ can feel like it is either damp or cold, but you can't really distinguish which? This morning, the NS felt neither damp nor cool to the touch. It was a dry feeling as when I had it in the house before I took it out. And no frost on the outside of the shell either.

To top it off, I attempted to "simulate" getting up and changing out in the filed by having my hiking clothes with me under the tarp. When I took off the sauna top, I did feel initially damp, but felt dry in a few seconds. i put a thick fleece over top of my smartwool and felt the same as I would without having used a VB. The same held true for my pant. I just slid the sauna pants off, felt damp and the cool air dried it almost immediately. I put my supplex pants on over top and felt just as dry as I normally would.

I can't help but see the advantage of not needing to field dry your gear or avoid packing it while it still retains the vapor from the previous night. Either way, you'll either save the time and effort of drying or the weight and loss of insulation of packing a quilt with vapor still trapped in it.

BillyBob58
12-27-2010, 13:30
A VBL bag will definitely work. I do have a couple of problems with it. First, it's a bag. I dislike VBL bags for the same reason I choose a TQ over a sleeping bag.
second, I HATE getting out of those things in the morning (or middle of the night) in the cold while I'm wet. VB clothing at least lets me move around under my TQ, and I can swap for dry clothing "one section" at a time come morning.

It is a real kick in the butt, coming out out a VB on a cold morning. That hits a lot harder than coming out of a warm jacket. All of which just demos how well it is working.

BillyBob58
12-27-2010, 13:37
......While you're not freezing, you can definitely feel the lack of warmth. With the VB stuff on, I felt no chill whatsoever and felt that I could have gone at least 10 more degrees lower if not more.

Now here's the interesting part. On top of the added warmth, I checked my NS when I got up this morning. You know the way a TQ can feel like it is either damp or cold, but you can't really distinguish which? This morning, the NS felt neither damp nor cool to the touch. It was a dry feeling as when I had it in the house before I took it out. And no frost on the outside of the shell either.....

BINGO! All theories and previous experience confirmed once again! Now for the final test if you feel like it: weight the NS before and after. Then use it in similar temps sans VB and weigh again.

wisenber
12-27-2010, 13:52
BINGO! All theories and previous experience confirmed once again! Now for the final test if you feel like it: weight the NS before and after. Then use it in similar temps sans VB and weigh again.

That might take a little bit of doing. First, I'll need to find a few nights in a row with the same temps. Next, the temps should be well below freezing else the NS might absorb moisture from the air. I'll probably need to wear some heavier layers without the VB as the VB seemed to keep me comfy at 21 in the NS.

I'll see what I can manage here in the next few days, but I think we are in for a warmer spell.

sclittlefield
12-27-2010, 16:47
Thanks for putting this together. You have such a great knack for simplifying tons of information and putting it together in one easy to understand package. Really nice work!

BillyBob58
12-27-2010, 23:12
Yeah, you're right. It would be hard to make a test that was comparing apples to apples. First you have to find two nights with the same temperatures. Plus, you have to have about the same humidity. In addition, just having to add clothes to make up for the lack of a vapor barrier would add another variable right there. Who could say how much moisture the clothing you wore would absorb. But, if you could account for all the variables, it would really be a useful test. If nothing else, if you had zero added weight using the vapor barrier, and then had some added moisture without using the vapor barrier, that would tell you pretty much all you needed to know. Even if the conditions were somewhat different on the two nights of testing.

MedicineMan
12-27-2010, 23:13
what you need is a walk in freezer :)

wisenber
12-28-2010, 11:20
what you need is a walk in freezer :)

...with trees :lol:

Dice
01-06-2011, 13:19
Any thoughts on these (http://www.supersaunasuits.com/HoodieSaunaSuit.asp)?

They look pretty functional, may not need so many layers, and they seem pretty comfortable! SuperSauna suit... interesting.

gnome
01-06-2011, 14:29
CUBEN, make a bag of lite cuben, weighs very little is vapor proof. gnome

Mat
02-09-2011, 18:25
When i used to Box i had a sil nyl two peice suit for training (Sauna Suit) and it realy does work, in the winter i would put that on under a fleece and some pants to go running and my sweat didnt soak my clothes, of course i was dripping under the suit but if you only wore it to sleep in i can realy see how it works to increase your bodys micro climate base temperature thus stopping any further sweating.... may have to try and find it now as im intrested to see how it works in the hammock!!!

d-p
02-24-2012, 11:38
Hangers,

Spent the last hour reading Vapor Barrier (VB) threads as dp hammocks and quilts use VB technology. ( small, light, not expensive, and easy to dry if necessary using synthetic insulation)


FYI: I've read often, the Mt. Everest climbers' down sleeping bags easily double in weight with moisture and ice, even tho they attempt to sun dry them out, if possible. It seems to me, at some point, synthetic insulation would be better than down?


Below is what works of me with Vapor Barrier technology ...

Synthetic long underwear and socks (don't like the VB feel against my skin)

Sleeping in pertinent clothes for temperature (NO cotton)

dp hammock that is nearly water proof (vapor barrier and can be used as rain gear)

dp top and under synthetic quilts with VB technology that is "next" to one's body, the outer fabric is DWR. (Allows for smaller, lighter gear in low temperatures)



I do not "hang" if temperatures are single digits F predicted.


I hope this reply may be of help to some ...

dp Dave

www.dphammockgear.com

www.dplightweightbackpackinggear.com

robbie g
07-01-2012, 04:38
Science often seems counterintuitive, and as with any piece of gear, VBLs only work well within a defined set of conditions. Just as you wouldn't say a winter quilt doesn't work well b/c it doesn't give good results in summer, a VBL will only give good results when used correctly.

Great illustration, dejoha!

Well said used at altitude or in severe winter conditions it works well , i use them over here in winter in the French Pyrenees , and get good results , it is a very good light weight piece of kit to carry on multi day sleep outs to test and find for your self and when your body reacts to the changes everyone is different, :)

Skygzr
07-01-2012, 08:25
I have a set of the RBH VBL cloths and they work great, but not sure whether this has come up in the post but most "waterproof", "breathable" fabrics like your rain gear are neither and can be used as VBL without having to buy anything new.

Skygzr
07-01-2012, 08:37
So, as I understand this thread, I could use:
First layer: lightweight silk underwear top & bottom,
second layer:driducks raingear top & bottom,
third layer: fleece pajamas,
then on feet: silk socks, bread bags, wool socks or down booties,
hands get thinnest possible gloves, surgical gloves, mittens.

Yeti under WBBB & TQ over all. Then just "ignore" the clammy feeling???

Would the driducks work differently if put on "inside-out" ?

Real curious about this thread.:):):)

It is important to remember with VBL technology that you need to vent...
You can't just put it on, zip it up and leave it. The idea is the you create a microclimate close to your skin that lets you stay warm in cold temperatures ( traps body heat) but you have to pay attention to your temperature and not overheat which will cause you sweat and feel "clamy" the idea is then to reabsorb that moisture and not let it escape. Most people don't like the feel of the VBL right nex to their skin so they use a thin base layer, this if perfectly fine, but more attention needs to be paid to your "inner climate"
I hiked once in North Dakota in January at -23 degrees and was only wearing a base layer and a VPL jacket and still needed to have it unzipped half way about every 30 minutes.

dejoha
07-01-2012, 09:28
This past weekend I was backpacking the San Francisco Peaks in northern Arizona. We set up our hammocks on the steepest incline I've ever hung on, not far from the trail, at 11,300 ft. It wasn't suppose to get very cold, maybe in the low 40s.

However, that night my body was pretty beat up with the days mileage and altitude and I was close to shivering in my 40įF-rated down top quilt. I was wearing every bit of clothing I had.

There was no chance of rain that night so I took my rain tarp (a GoLite Poncho Tarp) and wrapped it around my legs and lower torso before going to bed.

While not the ideal temperature conditions, the effect was immediate and welcome. I slept in this makeshift VBL all night and slept warm and comfortable. Since the VBL wasn't completely sealed, I had some moderate ventilation, but this "burrito" style really helped my body regulate its temperature until my metabolism kicked in.

In the morning, I pulled off my top quilt and my legs were still warm and cozy inside my tarp wrap. Pulling the tarp away, my legs immediately felt cool. It was amazing.

Typically, VBLs are recommended only in very cold and dry conditions. I wanted to share this experience because it gave me a sort of "last resort" method for staying warm in unusual circumstances.

While I was wrapped up enough to stay warm, there were enough "leaks" for venting that I didn't have any condensation issues. It was also very windy all night, which likely helped pull away a lot of moisture.

medrums
10-17-2012, 16:26
Thank you for the incredibly helpful illustration!

BillyBob58
10-17-2012, 21:21
............While not the ideal temperature conditions, the effect was immediate and welcome. I slept in this makeshift VBL all night and slept warm and comfortable. Since the VBL wasn't completely sealed, I had some moderate ventilation, but this "burrito" style really helped my body regulate its temperature until my metabolism kicked in.

In the morning, I pulled off my top quilt and my legs were still warm and cozy inside my tarp wrap. Pulling the tarp away, my legs immediately felt cool. It was amazing.

Typically, VBLs are recommended only in very cold and dry conditions. I wanted to share this experience because it gave me a sort of "last resort" method for staying warm in unusual circumstances.


Raisins bump of this thread helped me realize I missed your excellent report from last July, Dejoha. It is great to see this example of a VB saving you at least from an uncomfortable night in conditions that most would consider miserable for a VB, only in the 40s! That is NOT traditional VB weather, yet it saved your bacon, so to speak!

And you illustrated another point: only in the 40s, and due to being debilitated from a rough day, with a no doubt high quality 40F TQ plus all your clothing, you were close to shivering! Which probably would have only got worse during the night. That makes a point none of us should miss! May I ask, what was your UQ?

I bet you had some major evaporative cooling(EC) going on, even if temps were not very cold. VB to the rescue! Stops EC instantly! I'm betting that even if you had some minor condensation or clamminess, you still would have been warm. Better clammy than cold. Even if you outright sweat, better your thin base layers are damp than freezing from EC, plus that vapor is condensing or sweat soaking into your down night after night. The sudden evaporation of that moisture is what you felt when you finally took the tarp off, EC!

I see that 21% have used VBs successfully, much more than I would have predicted. I see that 73% have either never looked into them or are skeptical that they work at all. And 5% have used them and their clothes/insulation got really wet, which I assume was a negative experience. One which I have never experienced. I have been an advocate of VBs sense the 80s, when I got my 1st pair of Patagonia VB socks. For me, VBs have only served to keep my insulation dry as a bone, if you don't count the thinnest possible layer closest to my skin.

Over the years I have used VBs in various forms- mainly socks, but also glove inserts and most frequently space blankets in HH Super Shelters and in the bottom of a PeaPod. I plan to keep on using them, plus a VB shirt I have from Stephenson's Warmlite, and I hope to get some VB pants from them. I know you are supposed to be able to use your WPB rain gear as a VB, but I have a hard time seeing how it could work to full effect. Sense if I sit around in a true VB I tend to feel clammy as the humidity level at my skin reaches 100%. I never feel that in any of my WPB rain gear, so at least some vapor must be getting through.

Thanks for that informative real life report!

Winterwind
10-18-2012, 18:25
Excellent information, thanks!
I second this!

Wolfman
10-21-2012, 12:55
GREAT Thread! Massive information about VB. Not really something I had thought about before.

So for the simple and inexpensive option, assuming that someone did not have wads of cash to spend on VB clothing! You could use a VB bag, like the SOL or other brands, survival bag, just put in inside your sleeping setup not outside.

I used one of these survival bevies on the West Coast Trail last spring to stop the wind on a windy night, it worker great and I was warm all night, BUT it was on the outside of my sleeping bag (Ground camping) and when I woke the next morning the survival blanket had water on the inside and the outer shell of my bag was damp. Luck would have it that the morning was warm and sunny so I just hung them up and they dried quickly.

So if I was to do this again, of needed extra warmth for a cold night, the survival bevies should go inside the sleeping bag or top quilt, correct?

The one from Western Mountains looks like it was/is made for that, anyone have any experience with those? Are they noise makers like the SOL ones?

Wolf

BillyBob58
10-21-2012, 15:11
GREAT Thread! Massive information about VB. Not really something I had thought about before.

So for the simple and inexpensive option, assuming that someone did not have wads of cash to spend on VB clothing! You could use a VB bag, like the SOL or other brands, survival bag, just put in inside your sleeping setup not outside.

I used one of these survival bevies on the West Coast Trail last spring to stop the wind on a windy night, it worker great and I was warm all night, BUT it was on the outside of my sleeping bag (Ground camping) and when I woke the next morning the survival blanket had water on the inside and the outer shell of my bag was damp. Luck would have it that the morning was warm and sunny so I just hung them up and they dried quickly.

So if I was to do this again, of needed extra warmth for a cold night, the survival bevies should go inside the sleeping bag or top quilt, correct?

The one from Western Mountains looks like it was/is made for that, anyone have any experience with those? Are they noise makers like the SOL ones?

Wolf

In general, the idea is to have a VB between you and all layers of insulation. Because, as you experienced, whatever is between you and a VB will tend to get wet. Most will sacrifice a very thin layer of fast drying long johns between skin and VB, even though it will get damp, just because a VB feels pretty unpleasant against bare skin. That first layer will get damp, but all layers of thick insulation will remain bone dry, even if you have another sil-nylon water proof layer around all of the insulation.

Or the Stephenson's Warmlite VB clothing has a fuzzy layer on it meant to go against skin. The VB socks cost $8 and shirt $25. You won't be wearing these out to dinner and a date, they look pretty crappy. But they sure work, and you don't need to bother with a thin layer.

G...Hawk
10-25-2012, 18:38
Thank you all for the lessons.

This answers some questions.
Most importantly : creates a mind set of observation and practice.



G

toddhunter
10-26-2012, 12:47
I'm still trying to get it. I understand how it works. The VBL traps warmth, humidity and sweat near the body, keeping the insulation outside the VBL dry. But the part that is not explained well is the venting process, which apparently is required when you feel the (inevitable) perspiration. It sounds like as long as you manually vent at the moment you feel the sweat, this will keep you comfortable. I'm trying to picture this as convenient or comfortable.

BillyBob58
10-26-2012, 22:43
I'm still trying to get it. I understand how it works. The VBL traps warmth, humidity and sweat near the body, keeping the insulation outside the VBL dry. But the part that is not explained well is the venting process, which apparently is required when you feel the (inevitable) perspiration. It sounds like as long as you manually vent at the moment you feel the sweat, this will keep you comfortable. I'm trying to picture this as convenient or comfortable.

That is pretty much it, I think you have got it. But you won't necessarily have " (inevitable) perspiration", if by that you mean "sweat". The body produces that insensible perspiration to keep the skin moist, or so I have read. If that moisture disappears into the air and off of your skin, it can not only produce evaporative cooling ( same principle as an air conditioner or swamp cooler), but once it is gone your body just produces more. Then more cooling and even dehydration is contributed to.

However, inside a vapor barrier the humidity level will quickly be near 100%, and the vapor can not escape. So at that point, since the skins humidity level is at a maximum, your body stops producing this insensible perspiration. So if you maintain a just warm enough- but not necessarily cool/cold temp, you will not produce any more moisture. So you will not sweat, unless you actually overheat. It will feel a little ( or a lot) humid, but not necessarily wet.

Unless you actually go a little further and over heat a bit. Then your body tries to cool things down by producing sensible perspiration, or liquid, aka sweat. If this happens, you have used your VB at less than expert level. Then again, if you were having a hard time staying warm, and now a little sweat is your problem, it may not really be that much of a problem. And however much sweat you produce- due to overheating- it does not enter your insulation, but stays inside your VB. Not the most comfortable situation, but maybe more comfortable than shivering and better than wet insulation. I actually suspect that people using breathable insulation sweat a lot more than they realize when they are toasty warm, And their insulation is happy to soak it up so they don't even know that they have sweated. The sweat will be uncomfortable and very obvious, but contained and kept from the insulation, inside a VB. Any hint of actual sweat ( as opposed to just very high humidity or a muggy/clammy feeling) is a sign to vent. Maybe not to vent the VB, but to vent the insulation that is on top of the VB.

Just for the sake of experimentation, I put on a VB shirt about a half hour ago, at room temp. For about 15 minutes I have felt definitely too warm for comfort, and feel like I am on the verge of sweating. But I know from experience that if I sat outside at 60 or 65F, with a VB and no insulation, I would not sweat but would probably be warm enough. You should try such an experiment yourself, maybe with a bread sack used as a sock over a very thin layer of socks. But just remember the VB will make you warmer, so if you are already warm enough without the VB, you might sweat with it.

After a little over 1/2 hour, mostly sitting in my recliner, I took the VB off. I instantly felt a dramatic cooling ( but felt no such thing when I took my cotton T short off to put the VB on), but I found no signs of sweat. Not even on my back which was pressing into my recliner. But if the room had been even 2 or 3 degrees warmer, I'm sure I would have been sweating. But I might still take a little sweating over shivering cold and/or having any body moisture, maybe even outright sweat, getting into my insulation night after night. All depends on how cold it is and how long I'm going to be out.

I don't think it will ever be as comfortable as a breathable system, assuming you are warm enough in that system. But it can have dramatic warmth benefits for the weight and thickness, as well as keep your bags loft from getting a little lower every day under the right conditions. My rough guess of the temp difference between my cotton t shirt at room temp vs no t shirt and my VB shirt is 10 to 20F. From uncomfortably warm with the VB, to almost a little too cool with the VB gone and cotton T shirt back on.

DemostiX
10-30-2012, 02:32
I'm likely not the only one whose feet perspire differently from the rest of his/her body, so the treatment may need to be different.

I know they sweat,from the unsuitability of the popular and vapor-impermeable rubber "Crocs" for mine, the ones with thin fleece within the rubber shoe shell. Not surprised from distant similar experience, but I had to give Crocs a try because I got them as a gift from someone eager for me to appreciate them.

Just sitting around indoors, the fact that my feet had sweat-loaded the fleece was apparent from the evaporative cooling from the thin socks I was also wearing any time I slipped out of the Crocs, as well, of course, as from the damp of the shoe liner.

So, do any regular users of VBs have to make an exception for their feet? BillyBob?

RED531
01-22-2013, 11:47
thanks for all the info

ukarcher
02-28-2013, 16:22
Great thread guys.
for some years i've used the same cold weather format. Lycra (spandex) shirt and pants next to my skin, with cheap rubberised waterproofs as my VBL. (Jacket is tucked in my pants, and the wrists and ankles are elasticated to form a seal.) I don't use a VBL on my hands or feet, (just wool socks) as they seem to stay cool enough to regulate themselves. A wool hat completes the ensemble. I use a 3 season down bag with a full-length zip as my TQ, and a thermarest underneath. if its particularly cold, I use a folded sheet of closed cell insulation which is used for under laminate floors here, and can be cut to fit even the widest hammock. This and the thermarest go between the layers of my WBBB. With this set-up, I've happily camped in temps to -8c. In the morning, (or for midnight excursions) I stay warm, and my body feels comfortable. As anyone who wears spandex will know, when I take off my waterproofs to dress for the day, the spandex quickly dries out in the time it takes to shake out my fleece and walking pants. And unless there is a chilly wind blowing, this doesn't feel like i've been suddenly drenched in icy water.
I hope this helps anyone thinking of giving VBLs a try.

BillyBob58
02-28-2013, 18:26
I'm likely not the only one whose feet perspire differently from the rest of his/her body, so the treatment may need to be different.

I know they sweat,from the unsuitability of the popular and vapor-impermeable rubber "Crocs" for mine, the ones with thin fleece within the rubber shoe shell. Not surprised from distant similar experience, but I had to give Crocs a try because I got them as a gift from someone eager for me to appreciate them.

Just sitting around indoors, the fact that my feet had sweat-loaded the fleece was apparent from the evaporative cooling from the thin socks I was also wearing any time I slipped out of the Crocs, as well, of course, as from the damp of the shoe liner.

So, do any regular users of VBs have to make an exception for their feet? BillyBob?

Demostix, these bumps brought me back to this older thread, which made me realize I had eiher just missed your post or just forgot to answer it. Sorry bout that!

But I don't know how useful of an answer I can give. It is just going to require personal experiment which you may have already done by now.

But, no, I don't have to make an exception for my feet, at least not when sleeping or sitting around camp. I have never hiked with them yet, but I bet Fronkey has. But my feet have often become damp, more so than my torso when just sitting around in a VB shirt or pants.

I was in my HHSS the other day at a ridiculously cold feeling ( considering it was only 43F not minus 10 but felt cold! ) temp. I started out in a VB shirt with a light insulated jacket and that is all I needed on top while I was out, very toasty. But I noticed my feet felt sweaty in my UQ and nylon socks before i decided to add the VB socks. They still felt sweaty with the VB socks of course, but it was no worse.

Back later, got to go eat!

BillyBob58
02-28-2013, 22:50
OK, I'm back. So, about Demostix's question:

So, do any regular users of VBs have to make an exception for their feet? BillyBob?

Like you, I sweat in Crocs every time, which I mostly wear without socks. But this has not caused me problems in using VB socks, which is the main form of VBs which I have used, on and off since the early 80s. I learned about VBs from Patagonia catalogs from that era. Back in those days they did not make any breathable rain gear at all.

And it is not that my feet never get wet using these VB socks, because they do, even if more sometimes than others. But it is still warm, and keeps the footbox of my TQ dry. There have been times when I was very aware of the wetness. The first time or two it really freaked me out, because when I felt the wet my subconscious probably screamed " look out, cold feet and wet insulation is right at the door!". But the cold never appeared, in fact I was probably always noticeably warmer than without, although sometimes with an unpleasant wet sensation. I learned to ignore it if I was in need of the VB effect.

About the wet socks and Croc lining: in the case of VB liner sock or clothing ( or maybe bare skin ) it is sacrificed to the wet. That is why it is thin a layer as I can find. It's primary purpose is to reduce the unpleasant sensation of wet coated waterproof fabric on my skin. But some times, especially feet, this layer gets wet and I just ignore it. ( but no layer used with my current VB socks which are lined with "fuzzy stuff".

I have not noticed being wet or even damp wearing my VB shirt lined with fuzzy stuff except one day doing yard work and going up and down stairs into the attic. Sitting around at room temp or wearing the shirt under a Packa rain gear while walking as fast as possible in a cold rain, no sweat noticed.

About this last time in my HHSS and my feet were feeling clammy inside the footbox even without a VB, just nylon socks then not much worse when I put the VB socks on: makes me think about the time the Backpackinglight folks had a lot of trouble with the footbox ( and only FB ) of their down bags collapsing. With no exposure to external moisture. It also makes me think of the time the foot of my bag and foot of the HH pad ( and no where else ) were soaked with condensation the time I did not use the space blanket. Do the feet put out more moisture ( either sweat or vapor ) , even when it is cold, than the rest of our bodies? Does this account for a lot of the cold feet people get with thick wool socks and several inches of down around their feet? Due to all of this evaporative cooling in the feet plus that moisture getting into the down? If so, would a VB sock stop all of this, even if it gave you wet feet under the VB?

Sailor
02-28-2013, 23:12
I guess I'm just not as smart as I wish I was. I've read this a couple times, but still don't have a technical understanding of when/when not/where understanding in specific terms of use/not use, a VB.

What I've done in the past and understand is: below, insulate, and if a VB is used, have insulation between body and VB. On the whole, you can't insulate too much below. Above, insulate, and keep VB well above body, if used at all. Most important, stop the air from moving around.

Its general, but I don't have a better grasp.

Certain
03-01-2013, 03:13
I'm really glad to see this being discussed as I've always figured VB's are the probably one of the few options for me to really get down into cold temps since I'm such a cold sleeper. Back in 2007 when I was going through GSMNP, a huge snow storm came through and we had 15 miles to go to get out of the park, and my feet were freezing from the trail being flooded with cold wet rain/snow/slush, so I had two thin newspaper sacks and decided to use them as a VB to keep my feet warm (never tried it before, just remember having read about it). I put the sacks on over my bare feet, then my socks over that and then my shoes. I was hiking in slushy freezing cold snow and my feet were totally warm UNTIL the thin plastic bags finally got small holes in them and then my feet were instantly flooded with freezing icy water. Talk about a shock to the system. Ever since I used those VB's I've been curious a/b them for sleeping in cold temps.

ka8yiu
03-01-2013, 07:34
Sailor, as I read it, I think the VB needs to be between you and the insulation, not outside the insulation. This would cause the moisture to build in the insulation and collapse the insulation.

Not sure as I'm still a novice on it.

BillyBob58
03-01-2013, 12:45
I'm really glad to see this being discussed as I've always figured VB's are the probably one of the few options for me to really get down into cold temps since I'm such a cold sleeper. Back in 2007 when I was going through GSMNP, a huge snow storm came through and we had 15 miles to go to get out of the park, and my feet were freezing from the trail being flooded with cold wet rain/snow/slush, so I had two thin newspaper sacks and decided to use them as a VB to keep my feet warm (never tried it before, just remember having read about it). I put the sacks on over my bare feet, then my socks over that and then my shoes. I was hiking in slushy freezing cold snow and my feet were totally warm UNTIL the thin plastic bags finally got small holes in them and then my feet were instantly flooded with freezing icy water. Talk about a shock to the system. Ever since I used those VB's I've been curious a/b them for sleeping in cold temps.

Well, Michelle, if you can't keep your feet warm without them, then it looks like your next step is to find a VB sock ( or clothing or bag liner whatever ) material that is tough enough to withstand the use you put it too. Over many years I got some small holes in my 1983 era Patagonia VB socks, which I patched like one would patch a tarp. Not many though, as the material was pretty tough. I still have those but am much more likely to use my Stephensons Warmlight fuzzy stuff VB socks as they have a liner built in and feel better to me than my Patagonias with a thin separate liner sock. But I have never hiked much in either of them, so I'm not all that rough on them. I have mainly used them for sleep or as camp wear(SP?). But I can sure see they might have a place in very cold, snowy hiking. A loan of my Patagonias instantly solved a severe cold feet problem for a buddy of mine while we were fishing. That, to me, was a sign.


Sailor, as I read it, I think the VB needs to be between you and the insulation, not outside the insulation. This would cause the moisture to build in the insulation and collapse the insulation.

Not sure as I'm still a novice on it.

Yes, absolutely! You may be a novice, but you are right on the money! The VB -IMO and per general VB theory as fa as I know - is meant to be as close to the skin as possible. The only reason to wear anything under the VB is to decrease the unpleasant feeling of coated fabric and moisture on your skin, but nothing whatsoever is needed for the warmth function. A VB used any other way is pretty well going to leave a person hating VBs, and ending up wet and cold. Unless the VB is far enough away from your insulation so as to not cause trouble, like with a tarp for ex.

Guys/Gals, I think VBs are hard for some folks to comprehend only because it is exactly opposite of every thing we have ever been taught about how to keep warm, and why we must keep dry to do that. It is very hard to over come that bias, to the point that to purposely limit breathability seems almost stupid. It seems to be going in the opposite direction of where we should be going.

But in reality, like so many things here, once you get the theory it is all about as dirt simple as anything could be. Just think: opposite of breathable, but keep all the moisture close to the skin, keep it from evaporating ( evaporative cooling = swamp cooler/air conditioner), and keep that moisture- a little bit or a gallon- out of your precious insulation.

If you leave out the increased warmth factor, and probably even more important leave out the huge benefits of dry insulation after a week or three in the wild, then I don't think a VB will ever be as comfortable as nice breathable system. (Even though my Stephensons WL shirt has been coming close most of the time). It is just not as comfortable to have a sensation of damp or outright wet against your skin, no way. But for me, when throwing in the other benefits has sometimes made it a no brainer trade off. Plus growing skill with use has been minimizing the sensation of dampness/uber high humidity.

So, if you are a person who:
1: has decided they are always going to sweat no matter what, then there might be an advantage to figure out how to keep that sweat from evaporating/cooling and finding a way to keep it out of your insulation.
2: if you are in a group of folks who consistently find ( like a buddy of mine ) that after a cold week your quilts have a little less loft each day and weigh more at the end of a trip, even though no external moisture touches your quilts, you might want to figure out a way to keep your body moisture ( either vapor or liquid/sweat) out of your insulation in the first place. Rather than keeping on in the hope that all of that moisture making it to the outside of your insulation before it condenses into liquid. Maybe, but to each his own, and HYOH, etc.

There are several different types of VB. Like a tarp or pad or an HHSS UC, not meant to function as a VB, because the VB space blanket is meant to (hopefully) serve as the VB which keeps your body's moisture from reaching it in the first place. Also VB bag liners, and VB clothing.

But applicable to all of them, these general rules:
1: keep the VBs warm by keeping them close to your skin. Vapor condenses on cold surfaces, not warm ones.
2: Manage ( maybe reducing ) your insulation so that you don't over heat and sweat. Maybe even start out a little cold, add insulation as needed. You might need a lot less insulation than you do without a VB. Which might be a good thing, right?
3: if you do over heat and sweat any way, it might be safer to keep the sweat next to your skin than allowing it to get into your insulation. Which you find out about when you stop to rest and suddenly freeze, because your insulation is wet from sweat/condensation, even though your rain gear has kept all external moisture on the out side.

But, it is a learning curve! I'm still on this curve!

Jayson
03-01-2013, 13:31
After our recent trip on which temps. dropped into the -30*C range, I will not be out without my VB! I feel confident in saying they added at least 10*C to my insulation.

I wore them while sleeping over-top of my polypro baselayer longjohns, and covered with any layers that I needed. My quilts and sleeping bag did not gain any weight after three nights and the only frost on the bag was from my breath.
I never felt any clamminess or excessive wetness while sleeping and I did remove the VB in the morning. My wool clothing were plenty breatheable enough to deal with the moisture in my baselayer and it was dry in a very short time.

For me any nights that will be at or below the freezing point I will be utilizing a set of VB clothes.
The walmart sauna suit did not hold up to use in the really cold temps, I have decided to get a nylon wind shirt and pant set and give them the DIY silnylon treatment...should be much more durable!

ukarcher
03-01-2013, 14:03
Great information BillyBob,
You seem to be the go-to guy for info on VBLs. Having found an adequate solution for me personally, it never occurred to me that others might have such difficulty in finding a balance. Do you think people are having trouble because they are overheating, causing excessive sweating?
As an experiment, I've been wearing a pair of merino baselayer pants, with my cheap rubberised waterproofs over them, all today while doing my normal chores. i just checked my legs etc. for moisture by the simple expedient of dabbing with a dry tissue. Result, it was completely dry.

zscott
03-01-2013, 14:07
Great Illustration, so much talk about these VBL's but sometimes I don't think we always understand them.

ukarcher
03-02-2013, 04:37
I just thought of a good analogy to the VBL principle.
When scuba diving in cold water, I wear a 'dry' suit, over fleece coveralls. After an hour of moderate sub-aqua exercise, when I strip off, i'm still completely warm and dry.
So, I guess the secret of a good VBL is to try not to get 'too warm'.

BillyBob58
03-02-2013, 11:58
After our recent trip on which temps. dropped into the -30*C range, I will not be out without my VB! I feel confident in saying they added at least 10*C to my insulation.

I wore them while sleeping over-top of my polypro baselayer longjohns, and covered with any layers that I needed. My quilts and sleeping bag did not gain any weight after three nights and the only frost on the bag was from my breath.
I never felt any clamminess or excessive wetness while sleeping and I did remove the VB in the morning. My wool clothing were plenty breatheable enough to deal with the moisture in my baselayer and it was dry in a very short time.

For me any nights that will be at or below the freezing point I will be utilizing a set of VB clothes.
The walmart sauna suit did not hold up to use in the really cold temps, I have decided to get a nylon wind shirt and pant set and give them the DIY silnylon treatment...should be much more durable!

Wow, could the results be any better? Warmer AND drier (i.e. drier outer layers of insulation), does it get any better than that? All just from using VBs correctly, and according to standard VB theory.


Great information BillyBob,
You seem to be the go-to guy for info on VBLs.

Well thank you very much, but I'm not really the HF go to guy for VB info. Just look at the thread this is posted in by Dejoha, and Youngblood's older thread on the same subject ( is it a sticky? ). And the post by Jason I just responded to. And Fronkey should have a lot of info from recent and lengthy testing in severe conditions. I really look forward to that info. All I can claim is that I think I understand the basic theory plus have used them in various forms, on and off ( mostly off ) always successfully so far, for about 30 years. Plus, Stephenson's Warmlight has been a steady proponent of VB use for over 30 years. Still, thanks for thinking that! Maybe it just seems that way because I have been touting the approach more than others here for the last 6 years, in part for HHSS use? But that seems to be changing, several others seem to be greatly advancing our experience with VBs.


Having found an adequate solution for me personally, it never occurred to me that others might have such difficulty in finding a balance. Do you think people are having trouble because they are overheating, causing excessive sweating?Yes, absolutely. If you are already plenty warm with a given amount of insulation, and you add a VB, you are probably going to sweat. A VB usually means less insulation for a given temp. That and many have not quite understood the theory. Do it wrong, and you end up wet and cold. Having the first VB on the outside of even some of your insulation (not counting a very thin liner ) will probably be a miserable experience. If it is not next to your skin, then all layers better be breathable.


As an experiment, I've been wearing a pair of merino baselayer pants, with my cheap rubberised waterproofs over them, all today while doing my normal chores. i just checked my legs etc. for moisture by the simple expedient of dabbing with a dry tissue. Result, it was completely dry.Well, that is down right impressive. I stayed dry using a VB shirt and very little insulation walking very fast in cold, but above freezing and rainy temps. I even had a completely non-breathable rain wear sometimes(Packa). Bone dry. But when I did some harder work one cold day, I had to cut way back on my insulation because I started sweating. But I think my legs put out less moisture, I might have been OK with VB pants instead of shirt.


Great Illustration, so much talk about these VBL's but sometimes I don't think we always understand them.

I think the theory is pretty straight forward. Basically, just stop the vapor at the skin and maybe use less insulation than otherwise needed if you don't want to over heat and sweat. But if you do sweat, it's no disaster because the sweat can't get to your insulation.


I just thought of a good analogy to the VBL principle.
When scuba diving in cold water, I wear a 'dry' suit, over fleece coveralls. After an hour of moderate sub-aqua exercise, when I strip off, i'm still completely warm and dry.
So, I guess the secret of a good VBL is to try not to get 'too warm'.

That is certainly a major component of successful VB use. If you read about VBs on the Stephenson's Warmlight web site or catalog, ( heads up: they are nudists so the photos can get a bit different), they very much emphasize paying attention to if you are getting too warm and venting a bit as needed. Their VB info remains unchanged for about 30+ years. It is similar to info I used to get from the mountaineers at Patagonia also back about 30 years ago.

Still, unlike your dry suit experience, virtually all of your insulation is outside the VB. So if you do mess up and over heat and sweat, no big deal as far as getting sweat into your insulation. Maybe food for thought for folks that say they sweat no matter what.

PS: and what is that system you guys use over in the UK/Scotland, the total opposite of VB? Paramo? Not even water proof outer wear, but gear that is so breathable and wicks so efficiently and performs so well even when wet that it is great in wet weather? Even if you sweat it is quickly wicked away and the sweat has no effect on the very breathable insulation? I'm thinking Turnerminator(sp?) who just did the minus 40C trip used this gear? Sounds very interesting, though maybe heavy?

ukarcher
03-05-2013, 14:30
Class result Jayson. Did you have to vent at any point during the night? I haven't had the chance to try temps that low, but I am pretty confident I'd get similar results. (Isn't it great when things turn out how you want).

Billybob, i think 30+ years using VBL qualifies you as a go-to guy.
I think in my scuba analogy, I was trying to say that even though i was sealed completely inside my drysuit, providing I didn't get too warm, I didn't sweat enough to notice.
I have friends who swear by Paramo, and I would love to try out a Paramo baselayer, but every time i look into buying some, I convince myself that my lycra/spandex functions fine for me. (the £50 price tag for a shirt has nothing to do with it, honest)

On sweat points.. I took notice yesterday when i got back from my run, where my body sweats from mostly. My head sweat a lot. On my shirt, it was heaviest on my mid to low back, under-arms, and the middle of my chest. Only my nether regionsand a little behind the knees suffered on my legs, which again surprised me, considering the legs have the bodys biggest muscles, and were doing all the work. My socks were damp at the toes. I don't know what use that information is, except perhaps to pinpoint where a localised venting system would do me most good during heavy exercise. (though its interesting to note that regardless of which muscles were causing me to overheat, it was my trunk that did most of the sweating.)

sorry, I don't know how to insert quotes.

Jayson
03-05-2013, 15:14
No I didn't need to vent at all thru the nights. I went to bed each night wearing less clothes then I thought I would need with the plan to add as needed. Never needed to.

I forgot my foot bags and found I needed far more layers on my feet then anywhere else...but I get cold feet easily.

BillyBob58
03-05-2013, 16:17
Billybob, i think 30+ years using VBL qualifies you as a go-to guy.
I think in my scuba analogy, I was trying to say that even though i was sealed completely inside my drysuit, providing I didn't get too warm, I didn't sweat enough to notice. .

Right, and point well made. I.E., if you don't get too warm, even if your insulation is on the skin side of a VB, you will still not sweat and your insulation stays dry.

But condensation is a different issue. Still, even there you are making a good point, and without realizing it my testing has made the same point, which is: even condensation is probably only going to be so much, and not all that much. Your body - or so I read - puts out vapor to keep the skin moist, to keep it at a minimum humidity. Normally, as soon as this vapor appears, it travels out through your insulation, hopefully not hitting a cold enough temp to condense in your insulation. ( or if you sweat, that evaporates and then travels out, or is wicked out into the insulation). As it travels away, it is continually replaced by more vapor ( or sweat if too warm) production.

But, also as I have read, once you get near to 100% humidity at the skin, your body stops producing this vapor and/or moisture. There is no feed back signal of dry skin saying "send me some moisture". And unless you overheat, no more will be produced. And with certain insulations, any condensation that occurs before the shut off switch is thrown is apparently not enough to be a problem.

Hence, your "warm/dry" experience in a dry suit. Is that the normal experience of most folks in a dry suit? If so, why is your fleece not soaked after a long time in a dry suit/VB? It can only be - I think - because your body pretty quickly throws the "moisture shut off switch" as soon as adequate humidity is reached.

So, for the same reason, I can sit around in even room temp or close, in my VB lined with Fuzzystuff, with no problems. Sometimes it feels noticeably humid, but when I take the shirt off hours later it feels dry and has no weight gain. So there has apparently been very little vapor produced, and most of that probably right after I put the shirt on. The shirt is either bone dry when I take it off, or it has had so little moisture pumped into it in order to reach 100% humidity that, when I take it off it very quickly evaporates so it feels bone dry by the time I can get my hands on it to feel any dampness.

None of the above would apply to a VB that was further from the skin, like a sil-nylon sock several inches from the skin with a few inches of down insulation between it and your skin. It would take this space a while to reach 100% humidity, and you would just keep on producing this vapor. All night! Vapor which will readily condense when it hits an ice cold surface several inches from your body, so: wet insulation.

As I think about it more, I think your dry suit analogy gives us even more valuable info than I first thought. We need to ask why your fleece is not soaked using a dry suit, unless you over heat. Is it because your body quickly shuts down vapor production, unless you over heat and start sweating?

ukarcher
03-06-2013, 07:09
BillyBob, thats a lot of cerebral candy to consume.
It throws up a lot of questions.
Forgive me if i wobble on.You probably considered all this years ago.

below, though its probably the wrong terminology, i will use the expression 'dew-point'to indicate the point when vapor condenses.

Many of the people I've dived with, came out wet. Sometimes it was through leakage, but other peoples t.shirts looked exactly like they had just been for a run. I totally agree about the 'moisture shut off switch' I think it works better/worse in different parts of the body.
e.g. I think hands are much better at regulating themselves than feet.

considering the drysuit.... we have body, fleece, VBL(drysuit), then cold water. Even though the water is cold, there is not a big enough temperature change to induce the vapor to condense.

thought...the VBL micro-climate only works if you seperate it from the dew-point by using warm insulation. So, if we had no top quilt, then the warm vbl would be in direct contact with the cold air, causing an immediate dew-point, condensing the vapor to water, and collapsing the micro-climate.

With a cold drink on a warm day, we get condensation of moisture from the warm air on the outside of the can/bottle.

tin foil wrapped around an ice-cube in a warm room will collect moisture on the outside. I believe this is not from the melting ice-cube, but from the moisture in the warm air condensing at the dew-point on the foil. If we put insulation between the ice and the tin foil, there will be no condensation on the tin foil.

I would venture to say that wearing a VBL at room temperature should not cause wetness, unless you overheat, as there is no dew-point to condense the vapor inside into water.

d-p
03-06-2013, 08:15
Hangers,

Just bumped into this vapor barrier thread.

Give www.dplightweightbackpackinggear.com "bedroom" page a look because our sleeping bag and under-quilt engineering uses the VB principle, if you keep the coated material closest to one's body?

Coated material "outside", away from your body's heat? The VB priciple won't work as well.

But, On the other hand, the coated material on the outside, farthest away from one's body, can be used as a rain coat ...

dp wanting to keep one's gear as lightweight as possible, believes the vapor barrier is a good deal ...

Happy Trailzzzzzzzzzzzzzzzzzzzzzzzz
dp Dave

BillyBob58
03-06-2013, 14:05
BillyBob, thats a lot of cerebral candy to consume.
It throws up a lot of questions.
Forgive me if i wobble on.You probably considered all this years ago.

below, though its probably the wrong terminology, i will use the expression 'dew-point'to indicate the point when vapor condenses.

Many of the people I've dived with, came out wet. Sometimes it was through leakage, but other peoples t.shirts looked exactly like they had just been for a run. I totally agree about the 'moisture shut off switch' I think it works better/worse in different parts of the body.
e.g. I think hands are much better at regulating themselves than feet.


Curious, were they still warm, even though at least somewhat wet?

Also wondering: do you guys, while diving in drysuits, ever get hot enough to sweat?

Is there a "wetsuit"? if so, what is the difference?


considering the drysuit.... we have body, fleece, VBL(drysuit), then cold water. Even though the water is cold, there is not a big enough temperature change to induce the vapor to condense. But, if it was condensing- or even if not - I'm thinking once a certain humidity ( as always if NOT overheating and sweating) is reached, the body will stop producing vapor at the skin, vapor which might then condense? And probably at this point there won't be enough moisture to interfere with the insulation of the fleece? So you stay warm enough? I have absolutely no knowlege, other than what has been discussed here - of how dry suites work. In fact, I have always been curious about that.



thought...the VBL micro-climate only works if you seperate it from the dew-point by using warm insulation. So, if we had no top quilt, then the warm vbl would be in direct contact with the cold air, causing an immediate dew-point, condensing the vapor to water, and collapsing the micro-climate.Agreed! But, back from the oceans to the hammock, any insulation I have on the skin side of the VB will be very thin and minimal, to be sacrificed as far as insulation goes, more or less. It is only to make the VB feel better by not being in contact with my skin. But once again, even if the dew point is reached, the humidity is ( hopefully ) high enough that the body stops production of more vapor, so you only get so wet, and the wet can't evaporate ( so no evil evaporative cooling) and can't get into your real insulation. But going back to the dry suit example, it might be that with wool and synthetic insulations, if it only gets a little wet before the "vapor production switch" is turned off, maybe there will actually be even a hint of insulation still available from that next to skin layer. I just don't know!


With a cold drink on a warm day, we get condensation of moisture from the warm air on the outside of the can/bottle.

tin foil wrapped around an ice-cube in a warm room will collect moisture on the outside. I believe this is not from the melting ice-cube, but from the moisture in the warm air condensing at the dew-point on the foil. If we put insulation between the ice and the tin foil, there will be no condensation on the tin foil.

I would venture to say that wearing a VBL at room temperature should not cause wetness, unless you overheat, as there is no dew-point to condense the vapor inside into water. Sounds good to me UK, as good a bunch of theories as any other! I'm not enough of a scientist to be holding forth on this stuff. ( And yet I am any way, right? :rolleyes: )

But we are about to get what should be the final word, from extensive in the field testing of VB clothing by one of our own, Fronkey! The theories make for interesting conversation. But I can't wait to see the real world results, whether good or bad, the pros and cons!

ukarcher
03-07-2013, 22:13
Billybob, The drysuit comes in two types, Neoprene suits with built in silicone seals at the wrists and neck (the boots are built in), and membrane suits, which are waterproof nylon, also with silicone seals at wrists and neck. Underneath, you would usually wear a coverall suit of fleece or other insulating material. Usually, the diver stays nice and warm, (even if he gets a little damp). I dive in the North Sea, where the temperature ranges between 6c and 17c. As scuba is not a particularly energetic sport, (unless you're shore diving, and have a long walk to the water) its usually quite easy to maintain your temperature. I have simplified this a little as there are "dump valves" for getting rid of excess air from inside your suit, and an inflater valve to put some air in if you are getting "squeeze" from the water pressure. Once you have arranged this to your satisfaction, there is very little adjustment to be done. Anyway, thats how the suit works, so for the majority of the dive, all your body vapor stays sealed in there with you. So it tends to be beginners who are working hard that come out wet. I usually come out warm and dry, except for my cold fat lips, that were in direct contact with the water.
Sorry for wobbling on again.
I look forward to seeing what Fronkeys findings are :D

p.s. the wetsuit is neoprene but not sealed, and a thin layer of water lines the inside, to be warmed by your bodyheat. It isn't really an option for diving.

jjschaf
03-16-2013, 12:44
This is a quick simple and very helpful illustration. Thanks!

Scout620
03-25-2013, 10:32
Good article. Thanks

Pete
06-01-2013, 03:26
Good article. Check out DuPont - Tychem QC. Tyvek coated suits.

OneFoot
02-05-2014, 06:23
Thanks a bunch for the great info.

Clockw3rk
03-24-2014, 13:39
Your illustration style is a favorite of mine. Easy on the eyes and seems to lowers the blood pressure as you read. The information is concise and invaluable.
At least it was for me. Thanks for the thumbnail/gif too!

Poppins
12-27-2014, 14:07
Awesome thread!

Acoupland
01-10-2017, 12:09
This past weekend I was backpacking the San Francisco Peaks in northern Arizona. We set up our hammocks on the steepest incline I've ever hung on, not far from the trail, at 11,300 ft. It wasn't suppose to get very cold, maybe in the low 40s.

However, that night my body was pretty beat up with the days mileage and altitude and I was close to shivering in my 40įF-rated down top quilt. I was wearing every bit of clothing I had.

There was no chance of rain that night so I took my rain tarp (a GoLite Poncho Tarp) and wrapped it around my legs and lower torso before going to bed.

While not the ideal temperature conditions, the effect was immediate and welcome. I slept in this makeshift VBL all night and slept warm and comfortable. Since the VBL wasn't completely sealed, I had some moderate ventilation, but this "burrito" style really helped my body regulate its temperature until my metabolism kicked in.

In the morning, I pulled off my top quilt and my legs were still warm and cozy inside my tarp wrap. Pulling the tarp away, my legs immediately felt cool. It was amazing.

Typically, VBLs are recommended only in very cold and dry conditions. I wanted to share this experience because it gave me a sort of "last resort" method for staying warm in unusual circumstances.

While I was wrapped up enough to stay warm, there were enough "leaks" for venting that I didn't have any condensation issues. It was also very windy all night, which likely helped pull away a lot of moisture.





Sent from my iPhone using Tapatalk

OneClick
01-10-2017, 13:13
Good bump! Great old thread I somehow missed. I only use a VB on my feet. The Rab VB Socks I have are well worth the $40. Turkey roasting bags, bread, produce, newspaper bags don't cut it for me. A tear and you're done. But even if you are OK with their durability, the fit is all wrong. Having something in the actual shape of a sock is key for comfort, slipping down, etc.

I don't do it for warmth while wearing, not at all. I'll wear them even in warmer 25į because that's when I sweat a lot more in winter boots. So keeping that sweat out is so important since the low will likely be around 10į or lower...a BAD time to have even slightly damp boot insulation. Even worse, when it freezes overnight, you may never get them warmed up.

MonkeyWrench
01-12-2017, 18:44
I use a silnylon sock that wraps my hammock top to bottom with a foot and head vent with an overhang on each edge, if I'm getting to much moisture build up I just open up my vents a bit. When the vents are opened fully there's no moisture build up and at 18F I had an average inside hammock temperature of 52F with no wind chill. My underquilt also has two layers of insultex on the bottom side in addition to apex that completely blocks any wind that might rob my bottom insulation of heat.

P-Dub
01-14-2017, 12:49
Here's the correct link for Skurka's article listed in the OP
http://andrewskurka.com/2011/vapor-barrier-liners-theory-application/

Rouskof
01-18-2017, 19:00
This past weekend I was backpacking the San Francisco Peaks in northern Arizona. We set up our hammocks on the steepest incline I've ever hung on, not far from the trail, at 11,300 ft. It wasn't suppose to get very cold, maybe in the low 40s.

However, that night my body was pretty beat up with the days mileage and altitude and I was close to shivering in my 40įF-rated down top quilt. I was wearing every bit of clothing I had.

There was no chance of rain that night so I took my rain tarp (a GoLite Poncho Tarp) and wrapped it around my legs and lower torso before going to bed.

While not the ideal temperature conditions, the effect was immediate and welcome. I slept in this makeshift VBL all night and slept warm and comfortable. Since the VBL wasn't completely sealed, I had some moderate ventilation, but this "burrito" style really helped my body regulate its temperature until my metabolism kicked in.

In the morning, I pulled off my top quilt and my legs were still warm and cozy inside my tarp wrap. Pulling the tarp away, my legs immediately felt cool. It was amazing.

Typically, VBLs are recommended only in very cold and dry conditions. I wanted to share this experience because it gave me a sort of "last resort" method for staying warm in unusual circumstances.

While I was wrapped up enough to stay warm, there were enough "leaks" for venting that I didn't have any condensation issues. It was also very windy all night, which likely helped pull away a lot of moisture.

Used my tarp this way a couple times. It is hard to refrain when you freeze in the middle of the night and your tarp lies there unused because you expect no rain and no dew. "Tomorrow is another day", thought I ! Actually it was the last day, so I didn't care about having my sleeping bag wet (didn't respect the protocole of having the VB inside). But oh my, what a good cozy night I had inside this tarp ! I woke up in great shape !

I also put some plastic bags under my butt in desperation of warming it sometime, with great results and no sweating, actually the plastic bag was too thin, I think, so IMO it is all about dosing the remedy.

La Picker
01-19-2017, 20:50
Anyone have experience with one of these?

https://www.campmor.com/c/vapor-barrier-liner-regular-41360

I just got one but haven't had a chance to give it a test run yet. I'll post an update when I do.

oms121
01-23-2018, 10:13
Not that particular brand and model but I’ve tried VB liners in sleeping bags when I was a ground sleeper. Even on the ground, I found the separate liners to be cumbersome. They did keep my down dry and added warmth but were a single purpose item so I moved to VB clothing which can be worn in the sleeping bag/quilt as well as while moving around. I bought Stephenson’s Fuzzy Stuff shirt, gloves and socks. The shirt is comfortable for me without a base layer due to the fuzzy lining against the skin. Because it is waterproof and wind proof and I generate a lot of heat and moisture when exerting, I can wear it alone down below freezing while backpacking and often open it up completely to vent excess heat and moisture. Even if I get wet from sweat, the shirt does not hold any water so as soon as I cool down, I can zip up and put on insulating layers and I don’t get sweat in my insulation layers. It completely blocks wind also so it does double duty as a wind shirt when not generating heat and sweat. It is not fashionable but very versatile and great when you will be out for multiple days in sub freezing weather and you use down insulation.

The socks are great for many of the same reasons and, as another poster pointed out, keep moisture out of your footwear so you don’t risk frozen shoes/boots in the morning if you leave your footwear outside overnight. I usually hike in trail runners and find VB socks particularly helpful if I have to ford creeks in really cold weather. If the water is shallow and no danger of coming up over the tops of the VB socks, I just walk on through. If the water is deeper, I take off the VB socks, wade through (burr!) and then dry my feet, put the VB socks back on and keep on trucking. My feet warm up quickly and stay warm even though my shoes are soaked. I’ve had frozen fabric and shoelaces while walking but my feet were warm.

If you hike in sub freezing temps, particularly for multiple days at a tine and you use down insulation I would recommend you give VB clothing a try. It is a little tricky to balance the venting and insulation with your exertion level but even if you misjudge and start to sweat, you won’t sweat out your insulation layers which is critical in really cold temps. I suggest reading the VB info at the Warmlite site. They have been proselytizing about VB for 40 years.

Mark

OneClick
01-23-2018, 11:02
Anyone have experience with one of these?

https://www.campmor.com/c/vapor-barrier-liner-regular-41360

I just got one but haven't had a chance to give it a test run yet. I'll post an update when I do.

I was thinking about buying one of these. My experience with VB socks were SO amazing (warm feet after 20+ years of trouble) that I'm now looking to my sleep system. It hasn't been a problem yet, but I do get a lot of frost on my gear so I'm interested.

OlTrailDog
01-23-2018, 12:21
Excellent information and link.

Although it is valuable to experiment with VB hammocking for "emergency" situations you might put your self in, I think the cons outweigh the pros for most situations. Normal trip length for camping trips most likely doesn't result in excessive moisture accumulation in your insulation layer, unless you are doing something wrong or ill advised, e.g. too much insulation that you sweat like a pig (I know it isn't really accurate). Extended trips in COLD temperatures, as stated, VBs can be very valuable.

However, I have used VB socks, both silnylon and DIY plastic bags with inner liner socks. They work wonderfully for keeping telemark ski boot liners dry during extended back country travels. Most likely my feet would have been very uncomfortable or frost bitten without them. The other aspect of VBs is the abundance of bacteria that you create a tropical environment for. That is to say, your feet or body will be stinking. Also, using VB for extended periods can result in "trench foot" or "trench body" from the prolonged moisture and bacteria oasis you created.

OneClick
01-23-2018, 12:58
The other aspect of VBs is the abundance of bacteria that you create a tropical environment for. That is to say, your feet or body will be stinking. Also, using VB for extended periods can result in "trench foot" or "trench body" from the prolonged moisture and bacteria oasis you created.

I'm glad I haven't experienced that. It's nice to air them out even if it's just for a few seconds. Once a day was plenty for me. No odor or excess sweat, which seems weird, but that's just how it works. At night my feet get plenty of airing out...8 hours at minimum, a lot more if I'm just relaxing in the morning before putting VB socks back on. And at night, a quick wipe-down with rubbing alcohol keeps things clean. I always bring a small .5oz bottle anyway for washing my face and maybe body; gives you a nice quick fresh feeling when a bath/shower isn't possible.

I'm always pleasantly surprised when removing the VB socks. Every time I pause and think to myself "this is going to be gross"...but when I remove them it's basically just a slightly clammy foot. Probably not any worse than wearing a thicker sock by itself.

OlTrailDog
01-23-2018, 20:06
I'm glad I haven't experienced that. It's nice to air them out even if it's just for a few seconds. Once a day was plenty for me. No odor or excess sweat, which seems weird, but that's just how it works. At night my feet get plenty of airing out...8 hours at minimum, a lot more if I'm just relaxing in the morning before putting VB socks back on. And at night, a quick wipe-down with rubbing alcohol keeps things clean. I always bring a small .5oz bottle anyway for washing my face and maybe body; gives you a nice quick fresh feeling when a bath/shower isn't possible.

I'm always pleasantly surprised when removing the VB socks. Every time I pause and think to myself "this is going to be gross"...but when I remove them it's basically just a slightly clammy foot. Probably not any worse than wearing a thicker sock by itself.

I sure there is a range of experience depending on individual physiology. I'm not a person who sweats excessively, but when I remove my feet from the VBs I can wring my light weight synthetic liner socks out. I then tuck them under the sleeping pad so that the are pliable in the morning. Fortunately I'm also not renown for stinking feet, but after a five day ski touring trip or more my feet are rather unpleasant bed fellows. I never really experienced a lot of "relaxing in the morning" time. Usually it is more the case of how quickly can I stuff this all back together and start skiing to get the BTUs rolling. It is actually kind of amazing how quickly those clammy damp liner socks warm back up one the VB, liners, and boots are back on. Plus, how nice and dry the liners are. The clean up with the alcohol or wipes is a great idea.

Fortunately, I have never experienced "trench foot" either and have only read about it as a precaution.

OneClick
01-24-2018, 08:30
Yea that relaxing in the morning was just a bonus. If you're sleeping even 6 hours per night, you're feet should be happy.

SteveE
01-24-2018, 11:04
I struggle with the this. I truly see the value of keeping your bag/quilts dry (my winter trips often hit temps as low as -25C and I go for 5-6 nights), but I cannot stand the feeling of being clammy like that. I've used VBL socks (bread bags) and they did work good but man I hated the feeling of being clammy. I cant imagine feeling like that all over my body. On the flip-side I can see the value (and almost necessity) to keeping your bag/quilts moisture free on extended trips...

Who here airs their bag or quilt out during the day, or hangs it out in the sun to attempt to dry?

OneClick
01-24-2018, 11:24
Who here airs their bag or quilt out during the day, or hangs it out in the sun to attempt to dry?

If it's sunny and I'm not in a hurry to pack up, I'll do it. It doesn't hurt, even if you think it's completely dry. They're never really "wet" so just 10 minutes in the sun can burn off any dampness from frost or dew.

BillyBob58
02-08-2018, 14:13
Not that particular brand and model but Iíve tried VB liners in sleeping bags when I was a ground sleeper. Even on the ground, I found the separate liners to be cumbersome. They did keep my down dry and added warmth but were a single purpose item so I moved to VB clothing which can be worn in the sleeping bag/quilt as well as while moving around. I bought Stephensonís Fuzzy Stuff shirt, gloves and socks. The shirt is comfortable for me without a base layer due to the fuzzy lining against the skin. Because it is waterproof and wind proof and I generate a lot of heat and moisture when exerting, I can wear it alone down below freezing while backpacking and often open it up completely to vent excess heat and moisture. Even if I get wet from sweat, the shirt does not hold any water so as soon as I cool down, I can zip up and put on insulating layers and I donít get sweat in my insulation layers. It completely blocks wind also so it does double duty as a wind shirt when not generating heat and sweat. It is not fashionable but very versatile and great when you will be out for multiple days in sub freezing weather and you use down insulation.

The socks are great for many of the same reasons and, as another poster pointed out, keep moisture out of your footwear so you donít risk frozen shoes/boots in the morning if you leave your footwear outside overnight. I usually hike in trail runners and find VB socks particularly helpful if I have to ford creeks in really cold weather. If the water is shallow and no danger of coming up over the tops of the VB socks, I just walk on through. If the water is deeper, I take off the VB socks, wade through (burr!) and then dry my feet, put the VB socks back on and keep on trucking. My feet warm up quickly and stay warm even though my shoes are soaked. Iíve had frozen fabric and shoelaces while walking but my feet were warm.

If you hike in sub freezing temps, particularly for multiple days at a tine and you use down insulation I would recommend you give VB clothing a try. It is a little tricky to balance the venting and insulation with your exertion level but even if you misjudge and start to sweat, you wonít sweat out your insulation layers which is critical in really cold temps. I suggest reading the VB info at the Warmlite site. They have been proselytizing about VB for 40 years.

Mark
What he said!

Hey, OMS, I just saw this: not just another- rare - SWL VB fuzzy stuff user, but another southern SWL VB user! I'm thinking that has to be a rare combo(i.e. southern and VB user).

BillyBob58
02-08-2018, 15:14
I struggle with the this. I truly see the value of keeping your bag/quilts dry (my winter trips often hit temps as low as -25C and I go for 5-6 nights), but I cannot stand the feeling of being clammy like that. I've used VBL socks (bread bags) and they did work good but man I hated the feeling of being clammy. I cant imagine feeling like that all over my body. On the flip-side I can see the value (and almost necessity) to keeping your bag/quilts moisture free on extended trips...

Who here airs their bag or quilt out during the day, or hangs it out in the sun to attempt to dry?

I have a suggestion: Though I think they have increased in price since I got one, still fairly cheap compared to what folks often spend on gear: gamble $60 on a Warmlite VB shirt. Then first - if it is well above freezing but not summer time hot, just sit outside for a while wearing ONLY this ugly shirt on top(feel free to wear pants though! ). Don't add another layer unless you get a little cold. See how that feels. I think you might be surprised.

If not really bad, move it indoors. Preferably in an AC cooled summertime home, but even a winter heated home if you are not sitting in front of a fireplace and don't have the furnace cranked up over 72. But the idea is: test in a place that is not already hot, preferably just a bit on the cool side.

If you are like me, you will be surprised. Back in the early 80s when I 1st started experimenting with VB socks, I used unlined Patagonia and wore a thin layer of most likely polypro liner socks. The first time I almost panicked when early in the night my feet went from clammy to feeling outright wet, because wet = cold, right? Plus it was a downright unpleasant sensation. But after I realized that despite being wet, my feet were actually unusually warm, I just put up with it and had toasty- probably actually over heated- feet all night. Later when ice fishing with a visiting friend, he had a case of freezing feet. He took my offer to use my VB socks, and in less than 1/2 hour his feet were just fine.

That last was the 2nd experience, and I knew I was on to something, but I rarely took advantage of it over the years(actually, even forgot about it) because of how much I hated that clammy- ans finally out right sweaty- feeling. But I have actually managed to sit around inside my house wearing that VB shirt for a couple of hours at a time, with no problems, no sweat and did not even feel clammy. Same thing outside on cool days.

Sleeping in an HHSS at 6F? Was not even aware I had on anything different, other than being surprisingly warm considering my other gear, and being DRY inside those condensation traps known socks. Only the frost bib had any moisture on it. Other times I have been hiking or working outside in either kind of cold temps, like going up and down a ladder, and failed to vent properly and started to sweat profusely. One day on the home stretch of a day hike, I could tell I was starting to sweat a lot, but I was in a hurry and did not bother to remove layers(just unzipped) until I got to the car. I was really wet(needlessly so, I could have stopped and removed layers at the 1st sign of over heating), but it just did not feel a bad as my previous clammy experiences. But my outer layer(a cotton flannel shirt, worst possible for cold or wet)? Bone dry! And that is what is important: keep your insulation dry, from external and internal moisture. I'm certain that I sweat all the time when hiking, I just don't notice it much because it is wicked away from my skin and into my insulation. But more than once, I have definitely noticed it as soon as I stop hiking!

But if you are wanting to experiment with VBs, but can not stand the clammy feeling, I can personally recommend this brand. Not really wearable except in the woods, not a good looking garment for sure. But works and is way less clammy than other VB types I have tried, i.e. a simple coated VB over a thin synthetic layer. This feels better to me. OTOH, a garbage bag or some left over sil-nylon worn over a thin layer you already have is free. If you bought this and couldn't stand it, there probably is not much of a market for resale.
https://www.warmlite.com/product/no-sweat-shirt/

oms121
02-09-2018, 10:54
What he said!

Hey, OMS, I just saw this: not just another- rare - SWL VB fuzzy stuff user, but another southern SWL VB user! I'm thinking that has to be a rare combo(i.e. southern and VB user).

Yep. Iíve never run into another VB user, much less a Stephensonís Fuzzy Stuff user around here. I know one GA backpacker that has/had one of their tents but thatís it. I visited their office/home once when I was in NH hiking the Whites. Definitely idiosyncratic bunch. But very early VB adopters.

Plus, you gotta love their early catalogs!

OneClick
02-09-2018, 10:55
Weren't they the ones with naked people in the ads/catalogs back in the day?

OlTrailDog
02-09-2018, 11:42
Yep. I’ve never run into another VB user, much less a Stephenson’s Fuzzy Stuff user around here. I know one GA backpacker that has/had one of their tents but that’s it. I visited their office/home once when I was in NH hiking the Whites. Definitely idiosyncratic bunch. But very early VB adopters.

Plus, you gotta love their early catalogs!

I had a couple of Stephenson tents. Really nice light weight tents. I use to suffer majorly from a tent fetish and have the pleasure of using many different ones professionally and personally. But in the end I prefer modular pyramid tents like the Golite Hex3 (Shangra-La).

Speaking of VBs. I came across two full length VBs while looking for the bug net for the DH SL Raven I just sold. For using in a sleeping system. Any VB folks interested enough that I should post in the FS forum? One is made by Brooks Mountaineering and I don't remember what make the blue one is off hand.

oms121
02-09-2018, 13:19
Weren't they the ones with naked people in the ads/catalogs back in the day?

Yep. Thatís them! Glad they produced the catalogs when they were young!

TxAggie
02-09-2018, 13:45
Yep. Thatís them! Glad they produced the catalogs when they were young!

I stumbled across one online last week when I first started looking for VBLs. I was a little taken aback, now I canít find it again!

BillyBob58
02-09-2018, 13:49
Yep. That’s them! Glad they produced the catalogs when they were young!

I think that was from the nudist Mom and Dad founders. I think the son runs the company now and I do't think they do that any more, at least not from what I see in their online catalogue. I believe they have also moved from NH to CO But, I don't see any changes in the products for many years.

BillyBob58
02-09-2018, 13:50
I stumbled across one online last week when I first started looking for VBLs. I was a little taken aback, now I can’t find it again!

You mean the nudist stuff? You saw that last week? I don't recall seeing that for a while now.

TxAggie
02-09-2018, 15:00
You mean the nudist stuff? You saw that last week? I don't recall seeing that for a while now.

Yeah, Iím not sure how I stumbled on it. It looked like an older version of the site.

BillyBob58
02-19-2018, 23:52
In general, the idea is to have a VB between you and all layers of insulation. Because, as you experienced, whatever is between you and a VB will tend to get wet. Most will sacrifice a very thin layer of fast drying long johns between skin and VB, even though it will get damp, just because a VB feels pretty unpleasant against bare skin. That first layer will get damp, but all layers of thick insulation will remain bone dry, even if you have another sil-nylon water proof layer around all of the insulation.

Or the Stephenson's Warmlite VB clothing has a fuzzy layer on it meant to go against skin. The VB socks cost $8 and shirt $25. You won't be wearing these out to dinner and a date, they look pretty crappy. But they sure work, and you don't need to bother with a thin layer.


I have a suggestion: Though I think they have increased in price since I got one, still fairly cheap compared to what folks often spend on gear: gamble $60 on a Warmlite VB shirt. ...................

As you can see from my post from a while back at the top(post #60 in this thread 10/21/2012), they certainly have gone up a lot since I got mine- from $25 to $60. Almost tripled! Oh well, I would probably still pay it just to get the fuzzy stuff liner which works so well. But maybe thin merino wool, which many of us already have, would be just as comfortable under an unlined VB? If so, if one already had a very thin lightweight un-breathable piece of rain gear and merino wool, it would be a lot cheaper to test.

TxAggie
02-20-2018, 07:04
As you can see from my post from a while back at the top(post #60 in this thread 10/21/2012), they certainly have gone up a lot since I got mine- from $25 to $60. Almost tripled! Oh well, I would probably still pay it just to get the fuzzy stuff liner which works so well. But maybe thin merino wool, which many of us already have, would be just as comfortable under an unlined VB? If so, if one already had a very thin lightweight un-breathable piece of rain gear and merino wool, it would be a lot cheaper to test.

This is the route Iím planning to go. There are several PVC rainsuits on Amazon for $20-$30. They might not hold up great for a lot of hiking, but for a cheap VBL while sleeping with a thin layer underneath might be just the ticket. I have some silk base layers that are my go to and should be just about right for this.


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BillyBob58
02-20-2018, 10:02
This is the route Iím planning to go. There are several PVC rainsuits on Amazon for $20-$30. They might not hold up great for a lot of hiking, but for a cheap VBL while sleeping with a thin layer underneath might be just the ticket. I have some silk base layers that are my go to and should be just about right for this.


Sent from my iPhone using Tapatalk

It will be interesting to see if- assuming you also avoid over heating and sweating- you find this comfortable, as I do the Warmlite brand's fuzzystuff VB. Also, for the gram weanies among us, if it is weight efficient. I think my WL shirt XL is 8 oz, which includes the built in liner. I think even my thinnest Merino wool tops weigh close to that, so any extra dedicated VB layer would be some # of oz added on to that. Although, if it had any sort of dual purpose(rain gear?) or could replace one insulation layer due to it's added warmth and ability to keep other insulation drier, any reasonably small amount of extra weight might be negated.

TxAggie
02-20-2018, 11:05
In winter, itís not always about weight. A few ounces here or there that help provide a better nightís sleep or keep your other layers working optimally are well worth it.


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BillyBob58
02-20-2018, 18:41
In winter, itís not always about weight. A few ounces here or there that help provide a better nightís sleep or keep your other layers working optimally are well worth it.


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I could not agree more! Well worth it! Still, if I have to carry it on my back, AND I can get it done safely with less weight, I will choose that, if cost is not exorbitant.

Brewmaker
03-08-2018, 14:03
Super awesome thread, learned a lot. Thanks to everyone for sharing their experiences