Vapor Barrier Layers?

[todd kelly]

This is a new concept to me, is anyone using it in their clothing or sleep system for cold weather hunts?

 

[chindits]

Check out backpackinglight.com (BPL) for this topic as it is revisited this time of year every year. I was in a unit that issued feather friends bags with a VBL. It was a weird concept in the 90s and a lot of the troops didn't embrace it. I didn't give it much thought back then, but I used it. I don't remember any issues with it, but sleeping wasn't high on the list of priorities. I am just now starting to experiment with it.

Last month I was on 3 mildly cold weather backpack trips. The first trip was up around the Butte with temps in the mid 20s and I wore my rain gear over my base layer (improv VBL). I slept in a WM bag and had a tarp with open doors. I noted no condensation or frost issues on the outer shell of the bag. The second trip was in some canyon country west of Delta with temps in the 20s. I wore a base layer only and forgot to put my boots in my bag. I had the same WM bag and tarp with open doors. I had frost all over the outer shell of my bag. As I moved around in my bag in the a.m., I believe the stratified warm air in the insulation moved up to the outer shell and caused the frost to melt. My bag got wet and I had to dry out my gear in the a.m. My boots were frozen solid since stream crossing accompany most canyon trips. The next trip was up the Cochetope with temps below 10 degrees. I had the same bag and tarp, but I closed the doors that night. I also wore down pants, down jacket, and booties. I had my boots in the bottom of my bag to keep them from freezing. I also slept in a bivy bag. I woke up several times through the night very concerned about the frost build up inside the bivy bag, it seemed significant to me. The frost on the inside of the bivy bag also got on my sleeping bag.

When I get the time, I will try sleeping in my rain gear again to verify my first trips results or was it just different environmental factors.

I have no experience with VBL while not sleeping. Some folks on BPL have and some speak highly of it for keeping their insulation dry in extreme cold. I think Andrew Shurka is a big proponent of VBLs for his many cold weather jaunts.

 

[chindits]

Introduction: http://andrewskurka.com/2011/vapor-barrier-liners-theory-application/

 

[Wrongside]

Works great on extended cold weather trips in a guys sleep system. Helps to preserve your sleeping bag's insulation functionality, by reducing moisture trapped, and accumulated over days that never go above freezing, by condensation. Very effective and simple. Some guys never adjust to the 'clammy' feeling. It's never been a problem for me, but maybe depends on how hot/cold a person sleeps?

Never even tried a VB layer in my clothing. It might work if a guy was mainly sedentary? Might be worth a go while coyote hunting this winter...

 

[Jimbob]

liner socks, plastic bags, wool socks then hiking boots keeps my feet significantly warmer while hiking in the winter. No moisture gets out to the wool socks and my feet stay warm.

 

[todd kelly]

Thanks for the info guys!