PDA

View Full Version : Best Vapor Barrier Liner



Iceman
2006-05-09, 00:21
On extended trips in cold, or cool and damp weather my sleeping bags all tend to gain moisture and lose their insulative value. It is time form me to try a Vapor Barrier Liner for my sleeping system.

After a little research I intend to purchase a WesterMountaineering VBL HotSac, unless you talk me out of it and into something else....

http://www.westernmountaineering.com/index.cfm?section=Products&page=Accessories&viewpost=2&ContentId=44

Does anyone have experience with this product. Any tips or other recommendations?

dropkick
2006-05-09, 02:26
These might be the greatest thing ever, I have no way of knowing as I have no experience with them.

I'm still low tech, I line my bag with a percale sheet in summer and winter.
I've been doing so since I was a kid.

It adds quite a bit of warmth and doesn't weigh a lot.
I've never noticed any loss of insulation value in my bag while using one (maybe it soaks up the moisture instead of the bag?)
- Though in very cold weather I also add a blanket (was wool now fleece).

Also it is easy to air out or clean, and helps your bag stay cleaner, and last longer.

Mutinousdoug
2006-05-09, 16:38
So...
Essentially, you are wearing a plastic bag to bed? All that moisture that would have gone into your sleeping bag is in the plastic bag with you?
Your bag will be dry but you gonna be clammy, right? Do you towel off before you get dressed?

Take-a-knee
2006-05-09, 17:16
VBL's work well in a COLD dry environment, that is daily temps below 0 F. They will reduce the moisture a down bag will take on and enable it to maintain its loft. It will also reduce your insensible persperation as you sleep and help keep you hydrated. It will be clammy to some extent. You'll be one damp frigid muldoon when you wiggle out in the morning. Unless climbing in AK or the Rockies in the winter, this is probably a non-issue and you don't need one.

Rosaleen
2006-05-09, 19:50
Take-a-knee-

I thought the rule of thumb was well below freezing, not below 0 F. I've been fairly happy using my somewhat breathable rain gear or Frogg Toggs as a layer inside my bag in temps between maybe 25 to 33 F.

Rosaleen

Take-a-knee
2006-05-09, 21:16
Vapor barriers work better the colder it gets. If the outside of the sleeping bag never approaches 32 F then ALL of your insensible perspiration is staying in the bag, if the bag is down this can have very bad consequences. I can't say how well Frogg Toggs would work, I would think you would need something waterproof to allow your microclimate to get humid enough to slow your rate of perspiration down. If there are any of you guys out there that have used "Mickey-Mouse" boots (vapor barrier military boots) there is absolutely nothing as warm as they are. We used to wear them with no socks as long as we were moving (at -40 F) and our feet didn't get nearly as sweaty as they did with socks on.

Rosaleen
2006-05-09, 21:25
Frogg Toggs are fairly breathable, but hold in heat. I was using them as a layer in staying warm. I don't agree ALL insensible is staying in a sleeping bag if the temp is around 32 F. There will be at least SOME perspiration as water vapor that body heat will drive off...unless there is a vapor barrier right on the outside layer. We were very cold in approximate 35 F rated bags until we layered our fleece and Frogg Toggs on our bodies, inside our sleeping bags a couple of years ago in Yellowstone -early July, I believe.

Rosaleen

Iceman
2006-05-09, 23:39
I have read that as you "lock in" a bit of your body moisture, your body does not continue to pump out the "insensible perspiration" all night long, in effect, reducing the amount that you perspire at night, your body is now not required to replace lost humidity. I believe this is why without the barrier, so much moisture is found at or near the surface of a bag in the morning... The interior surfaces of my bag are not wet at all. Rather, the moisture that my body created overnight, has been drawn to the colder side of the insulation-the surface which is at or near freezing, my body recognizes this lost humidity and sends out more. Remember, I am talking cold nights, and more than one night out, or who cares....

From what I have also read, clammy yes, but not so much that you are dripping. Also have read that as your humidity level at your skin surface gets "happy", your body stops sending water out...

Also remember, my body has twice the surface area as most of you skinny rats...twice the suface area, twice the moisture... Have you ever seen a big guy sweat? :biggrin:

All bets are off if you pee yourself.

Rosaleen
2006-05-10, 00:08
Gotta luv a guy with a sense of humor!

Rosaleen, not quite PIMP, but definitely LOL

Just Jeff
2006-05-10, 00:50
One more effect - as your body stops producing more moisture, the perspiration is no longer evaporating, which means you're no longer losing heat through evaporative cooling, which means you stay warmer at night.

I've only used VB socks, but they made a pretty big difference in keeping my feet warm. Other than that, I used my wp/b raingear as a pseudo-VB and it also makes a difference in keeping me warm.

CanoeCamper
2006-05-19, 16:11
I noticed on the price list that the hotsack is $85.
This (http://mosquitohammock.com/survivalbag.html) is $40.

Hog On Ice
2006-05-19, 16:45
looks like a mighty short zipper on that Sapce Survival Bag - aka a PIA to get into in a hammock

Iceman
2006-05-20, 02:37
I noticed on the price list that the hotsack is $85.
This (http://mosquitohammock.com/survivalbag.html) is $40.

Thanks, I also found a really cheap version over at Campmor for $25. Maybe I should try this cheapo before going big!?

http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=7646&memberId=12500226&storeId=226&catalogId=40000000226&langId=-1


Also, can someone send me a PM and educate this dufus :damnmate: about how to re-label/name my links so they look cooler than the p.o.s. I just posted above. :adore:

incognito
2006-05-20, 09:38
Fat Rats will always have the moisture problems within their bags, but keep on lookin, nothing ventured nothing gained :biggrin:

Just Jeff
2006-05-20, 10:59
...educate this dufus...

- Click "Go Advanced" or "Quote" to respond to the message - you can't do it in "Quick Reply"
- Type the text you want to link with - like "this link"
- Highlight the text
- Click the hyperlink button - the one with the globe and chain links in the middle of the bottom row
- Enter the URL in the box and click OK

It'll look like this link (http://www.tothewoods.net/JeffsHikingPage.html) to my page.

Not a PM, but you're probably not the only one who doesn't know how to do it!

Iceman
2006-05-20, 11:55
- Click "Go Advanced" or "Quote" to respond to the message - you can't do it in "Quick Reply"
- Type the text you want to link with - like "this link"
- Highlight the text
- Click the hyperlink button - the one with the globe and chain links in the middle of the bottom row
- Enter the URL in the box and click OK

It'll look like this link (http://www.tothewoods.net/JeffsHikingPage.html) to my page.

Not a PM, but you're probably not the only one who doesn't know how to do it!

LIKE THIS? (http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=7646&memberId=12500226&storeId=226&catalogId=40000000226&langId=-1)

Just Jeff, You Da' Man! :adore: :adore: :adore:

Alright kiddies, tune in next week when Just Jeff will show Iceman how to properly place photos in a thread, eliminating the need to use attachments...

And, regarding me not being the only one who doesn't know how to do "it" (something, anything...) I have found it far better to recognize what you do not know, than fake it. Keeps me out of trouble...

blackdog
2006-05-20, 13:12
Also, can someone send me a PM and educate this dufus :damnmate: about how to re-label/name my links so they look cooler than the p.o.s. I just posted above. :adore:
You can code it too, like this:

SGT Rock's Hiking HQ
(replace the word gomi in the above line with url and the code actually works).

the above produces this result: SGT Rock's Hiking HQ (http://www.hikinghq.net)

Just Jeff's way to do it is much sleeker, though. :)

dropkick
2006-05-21, 16:57
Iceman,
After careful thought about your vapor barrier problem I believe I've come up with a less expensive alternative!
You could smear yourself down with Crisco and then wrap up in plastic wrap!!:stupido2:
If you covered your body completely there wouldn't be any body vapor problems at all!
If you wrapped your arms and legs seperately you wouldn't have to remove it in the morning, and you could benefit from the vapor barrier all day too!
And in the morning you could grease up the breakfast skillet with your belly - making it dual use!




--If you use this idea, when you show your it to freinds, neighbors, and casual acquaintances you can take all the credit for it's invention, as I'm to modest and don't want the acclaim.

:ahhhhh:

Redleg
2006-05-21, 18:44
Iceman,
After careful thought about your vapor barrier problem I believe I've come up with a less expensive alternative!
You could smear yourself down with Crisco and then wrap up in plastic wrap!!:stupido2:
:ahhhhh:

Only if I can run the Platoon past at wake up. It would repace the bra in the XO's jocky-box as a topic of conversation.
jaf

Iceman
2006-05-21, 23:06
Geesh', I am sure glad I didn't say anything about the chafing between my thighs, the boil on my shoulder, flaking dandruff, athletes foot, my chronic halitosis, or my twisted testicle, you may have given me some crud over it all. (Horrific thought isn't it?) Actually, crisco works, but it attracts the bears too much, I prefer vaseline. Vaseline is great cause I can roll the lint ball in my bellybutton around and it makes a great firestarter. Dual Purpose! But then again, If I used the crisco, I could grease my frypan by swirling it around on my belly before cooking for you all. Maybe I will try the crisco again. :biggrin: