Winter Snow Sport Gear
Winter Hiking & Snowshoeing
Amazon.com
Backpacking Forums
---- Our Gear Store ----
The Lightweight Gear Store
 
 WINTER CAMPING 

Shelters
Bivy Bags
Sleeping Bags
Sleeping Pads
Snow Sports
Winter Kitchen

 SNOWSPORTS 

Snowshoes
Avalanche Gear
Skins
Hats, Gloves, & Gaiters
Accessories

 ULTRA-LIGHT 

Ultralight Backpacks
Ultralight Bivy Sacks
Ultralight Shelters
Ultralight Tarps
Ultralight Tents
Ultralight Raingear
Ultralight Stoves & Cookware
Ultralight Down Sleeping Bags
Ultralight Synthetic Sleep Bags
Ultralight Apparel


the Titanium Page
WM Extremelite Sleeping Bags

 CAMPING & HIKING 

Backpacks
Tents
Sleeping Bags
Hydration
Kitchen
Accessories

 CLIMBING 

Ropes & Cordage
Protection & Hardware
Carabiners & Quickdraws
Climbing Packs & Bags
Big Wall
Rescue & Industrial

 MEN'S APPAREL 

Jackets
Shirts
Baselayer
Headwear
Gloves
Accessories

 WOMEN'S APPAREL 

Jackets
Shirts
Baselayer
Headwear
Gloves
Accessories

 FOOTWEAR 

Men's Footwear
Women's Footwear

 CLEARANCE 

Backpacks
Mens Apparel
Womens Apparel
Climbing
Footwear
Accessories

 BRANDS 

Black Diamond
Granite Gear
La Sportiva
Osprey
Smartwool

 WAYS TO SHOP 

Sale
Clearance
Top Brands
All Brands

 Backpacking Equipment 

Shelters
BackPacks
Sleeping Bags
Water Treatment
Kitchen
Hydration
Climbing


 Backcountry Gear Clearance

Page 2 of 2 < 1 2
Topic Options
Rate This Topic
#105021 - 10/21/08 06:03 PM Re: Vapour Barrier Clothing [Re: ringtail]
Earthling Offline
member

Registered: 02/22/03
Posts: 3228
Loc: USA
Also Dick, the venting on the neck and hem of a VB shirt is not like a regular crewneck. If it was then it would'nt allow the approairate moisture level to build and work with the VB shirt. Definitely tech clothing for the gear fiddler amongst us. I had a tone of it in the 70's, and then lost much of it while moving in the 80's <img src="/forums/images/graemlins/tongue.gif" alt="" /> along with some of my LP collection <img src="/forums/images/graemlins/crazy.gif" alt="" />
_________________________
PEPPER SPRAY AIN'T BRAINS IN A CAN!

Top
#105022 - 10/21/08 06:52 PM Re: Vapour Barrier Clothing [Re: Earthling]
Cesar Offline
member

Registered: 11/06/07
Posts: 217
Loc: El Paso, TX
quick question, how do you keep all your sweat from pouring out of your VBshirt onto the inside of your bag when you sit up. I guess the same goes for a VBLiner. You must need to get out carefully to keep from getting your bag wet. Also if its that cold that your body vapor can freeze in the down isn't it dangerous to unzip your bag and get out while wet at such low temps?
_________________________
My gear is no where near lightweight

Top
#105023 - 10/21/08 09:00 PM Re: Vapour Barrier Clothing [Re: TomD]
Paul Offline
member

Registered: 09/30/02
Posts: 778
Loc: California
Quote:


Now back to our regularly scheduled program. From what I read, I though the idea was that once you reached essentially 100 per cent humidity in the vbl bag, you'd stop sweating because the evaporation would stop. Not so?



Tom, this is the basic theory ONLYas it applies to "insensible" perspiration, and ONLY if you are at an equilibrium temperature - not hot, not "sweating". If you are hot, and your body is producing sweat to cool itself off, you will continue to do so regardless of the humidity. Again, it's all about managing the insulation to acheive that teperature equilibrium. Not too hard to do for sleeping or sitting, VERY hard to do while active.

Top
#105024 - 10/21/08 11:11 PM Re: Vapour Barrier Clothing [Re: Cesar]
phat Offline
Moderator

Registered: 06/24/07
Posts: 4107
Loc: Alberta, Canada
Quote:
quick question, how do you keep all your sweat from pouring out of your VBshirt onto the inside of your bag when you sit up. I guess the same goes for a VBLiner. You must need to get out carefully to keep from getting your bag wet.

The idea with a VBL liner is *not* to sweat a lot in it. As for a VBL shirt, rick's not talking about wearing this in the bag - he's talking abou wearing it while walking in subzero.
Of course you have to be careful.

Quote:

Also if its that cold that your body vapor can freeze in the down isn't it dangerous to unzip your bag and get out while wet at such low temps?


If this were the case Canada would have never had human occupation because their bladders would have burst as we all steadfastly refused to leave our sleeping bags/buffalo robes. (then again I know I've had mornings that felt like that <img src="/forums/images/graemlins/smile.gif" alt="" />

it's not like you're sitting in the bag soaking - the problem is not that you are dripping - the thing you have to remember is this isn't that you're wet, it's just the natural water vapor that comes off your skin that freezes. Think about when you are in a single wall tent - you're not wet, but there's a bunch of moisture on the inside condensed in the tent. A lot came from your breathing, but some came from water coming right off your skin. In really nasty cold, that water doesn't go up and condense on your tent, it condenses, then freezes,
inside the sleeping bag. and if it's down that can really suck. The VBL doens't leave you sweaty (or it shouldn't in a bag) It should leave you comfortable, not dripping.

and as for getting out - you can always get out in such weather - you just can sit outside naked and wet with no chance of getting dry and warm.
_________________________
Any fool can be uncomfortable...
My 3 season gear list
Winter list.
Browse my pictures


Top
#105025 - 10/22/08 08:43 AM Re: Vapour Barrier Clothing [Re: phat]
alanwenker Offline
member

Registered: 02/04/03
Posts: 812
It's worth keeping in mind there is a large difference between getting out of one's bag and vbl with one's long underwear slightly damp (but warm) versus being totally sweat soaked with perspiration running down one's body and a pool of sweat inside the vbl. Frequently in vbl discussions I think the later image is what is conveyed, but in my case the former image is what I've experienced. I'm not referring to vb clothing worn when active, but mainly just in a sleeping mode where one is not moving around. I'm 75% certain I like the vbl for sleeping, but have to make time to experiment with vb shirts.

Top
#105026 - 10/23/08 02:03 PM Re: Vapour Barrier Clothing [Re: Rick]
whcobbs Offline
member

Registered: 10/14/02
Posts: 227
Rick--
For several years I have used a hooded silnylon rainsuit as a vb suit for sleeping in subfreezing temps. Lightwt polypro longjohns go next to skin, then the rainsuit, then a stretch layer (pp/Lycra balaclava, power stretch ski suit or alternately polypro stretch bike jersey and winter polypro biker tights, then the insulated clothing ( Parka, insulated pants, finally a 2lb synthetic overbag. This scheme will dry out the damp clothing from the day's hike with body heat and dissipate the moisture through the bag. Do not try it with a down bag or with temps above freezing! Lightweight.
Walt

Top
#105027 - 10/23/08 03:14 PM Re: Vapour Barrier Clothing [Re: whcobbs]
OregonMouse Online   content
member

Registered: 02/03/06
Posts: 6799
Loc: Gateway to Columbia Gorge
My experience with using a vapor barrier in a sleeping bag is limited to six below-freezing nights in the Rockies last summer. After the first frosty morning, when my down bag was distinctly damp, I remembered what I'd read about vapor barriers and tried wearing my non-breathable (silnylon) rain jacket and pants to bed over my base layer. It worked just fine. I avoided getting sweaty in the early evening by leaving my sleeping bag open (please remember that this was a Rocky Mountain summer, not a Canadian winter!). Usually after the second time I woke up (one of the problems of aging is that I have to get up several times during the night), I'd zip the bag up. By about 2-3 am, I'd have to snug up the draft collar in my sleeping bag. A couple of nights I was borderline cold about 5-6 am. Those were the nights my dog's water dish froze solid, leaving one puzzled dog in the morning! I didn't sweat and didn't even feel damp. My sleeping bag stayed dry, too. I normally do a lot of sweating, so this was a big surprise to me!


Edited by OregonMouse (10/23/08 03:15 PM)
_________________________
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey

Top
Page 2 of 2 < 1 2

Shout Box

Highest Quality Lightweight Down Sleeping Bags
 
Western Mountaineering Sleeping Bags
 
Lite Gear Talk - Featured Topics
Backcountry Discussion - Featured Topics
Make Your Own Gear - Featured Topics
Featured Photos
Spiderco Chaparral Pocketknife
David & Goliath
Also Testing
Trip Report with Photos
Seven Devils, Idaho
Oat Hill Mine Trail 2012
Dark Canyon - Utah
Who's Online
0 registered (), 160 Guests and 0 Spiders online.
Key: Admin, Global Mod, Mod
Newest Members
Noodles, McCrary, DanyBacky, Rashy Willia, WanderBison
13240 Registered Users
Forum Links
Disclaimer
Policies
Site Links
Backpacking.net
Lightweight Gear Store
Backpacking Book Store
Lightweight Zone
Hiking Essentials

Our long-time Sponsor, BackcountryGear.com - The leading source for ultralite/lightweight outdoor gear:

Backcountry Forum
 
 

Since 1996 - the Original Backcountry Forum
Copyright © The Lightweight Backpacker & BackcountryForum.com