Backyard testing at 14F

**Just Jeff** · 01-02-2010, 10:54

Yeah - that's mostly wrong...you DON'T WANT the moisture to escape. It needs to stay inside your VB so your body will stop producing moisture. With a real VB the moisture will only escape at the openings. With a pseudo-VB like wpb raingear, you'll get a little bit escaping thru the fabric...but your insulation will still be warm so whatever moisture gets into the insulation will move thru just as easily as it would have otherwise. In theory, you may find more localized moisture...at the zipper, for example. I don't know if there would actually be enough of that to notice it unless you're actually sweating, though.

Remember that the threshold for "breathable" clothing is ridiculously low...passing something like 2% qualifies as breathable.

When I use a VB, I wear silkweight thermals, my raingear, then my insulation. One time I wore my fleece inside my rain jacket and my fleece was damp in the morning. Next night, almost same conditions, I put the fleece on the outside and could easily tell a difference in moisture and in warmth.

**YardDog** · 01-02-2010, 10:57

Originally Posted by NCPatrick

Whoohoo!

Looks like it's time for some backyard testing tonight!

That's exactly how I got my nickname! My wife laughingly called me a yard dog the first time that I slept in the yard with my first hammock.

I actually did some back yard testing of my own this past Tuesday night. It only got down to 28... not the low 20s as was forecast.

I must admit, it's supposed to get down to around 17 here tonight and the thought did cross my mind...

**slowhike** · 01-02-2010, 11:00

I fully agree w/ what Jeff said, but as a side note, if you're standing around camp, inactive, the somewhat breathable but highly wind resistant outer layer is a very good thing, especially if there is any breeze.
But as soon as you feel the slightest bit overly warm, start to open up that outer layer to vent.

Of course that's a wind shell approach rather than a vapor barrier. Just making mention of the difference between the two.

**Cannibal** · 01-02-2010, 11:06

OK, that makes sense to me. Using the warm humid air to keep warm and trick the body. I've only used raingear a few times and it was more out of concern of the wind when I didn't have great tarp coverage. I'm way too warm of a sleeper to even consider messing around with VBs, but I like having at least a basic understanding in case things get ugly. Thanks!

**Just Jeff** · 01-02-2010, 11:06

Yep - don't want the wind stealing your heat. I use the VB when I'm under my quilt.

**vitamaltz** · 01-02-2010, 11:07

BTW, I've come to use Tyvek booties as my nature-call shoes. They stay with me in the hammock and can be slipped over my sleep socks in a wink - they keep the socks dry on the way to the tree unless it's really raining. I have a box of 'em and will bring some to Mt. Rogers if I make it down there.

**Perkolady** · 01-02-2010, 11:21

I've slept in my wind shirt and pants a few times. I had on a midweight top and pants, then windshirt and windpants, then fleece jacket and pants over them. Worked out pretty well!

Then, in the same weather, I also tried sleeping with the midweight layer, then the fleece, then my frogg toggs rain gear, but froze my butt off! (though, I still have some of it left

)

I like that idea of the Tyvek booties, vitamaltz!

**NCPatrick** · 01-02-2010, 11:54

I have some Tyvek booties that fit over my down booties. I've never used them because until I modified the down booties yesterday they weren't fitting well enough to bother with. Of course, VB theory would say to wear the tyvek INSIDE the down booties, right? For late night tree waterings I'm not going to bother with theory though.

**vitamaltz** · 01-02-2010, 11:57

Yeah, but I think good old plastic bags are the best foot VBs. The idea of the booties is just to keep my socks dry, clean, and leaf-free. I don't think they add much to the warmth, but they're a quick camp shoe - a lot easier than taking socks off or putting boots on.

**BillyBob58** · 01-02-2010, 12:40

Originally Posted by Cannibal

That's why I always wore my Frogg Toggs on the outside of everything. In my mind, it allowed for a little looseness in the material which I figured would allow any moisture to vent a bit anyway. My concern with putting it between layers is that any moisture trapped by it's VBish properties would have a more difficult time finding escape.

Am I wrong in my thinking? I am mostly a VB moron.

Funny image!

Originally Posted by Just Jeff

Yeah - that's mostly wrong...you DON'T WANT the moisture to escape. It needs to stay inside your VB so your body will stop producing moisture..

Yep, a very thin but wet and yet warm layer- or bare skin for some- then the VB. This layer never feels particularly pleasant for me, but I have no doubt it significantly increases warmth. Back in the day, I still remember my buddy had freezing feet. He borrowed my VB socks, placed between a thin polypro sock layer and the thicker wool socks. Withinn a short time, his feet were plenty warm.

The theoretical benefits are to 1: stop evaporative cooling 2: to stop production of insensible perspiration and the dehydration this can add to and 3: to keep any body moisture out of your insulation, where it may condense no matter how breathable the shell. And where it will at least add humidity under the best of circumstances.

However, you will have wet skin, which can feel down right weird. Even a little scary at first, sense instinct is to avoid being wet. But unless you over heat and sweat, it only gets so wet, then moisture production should stop. Of course, if you over heat and sweat, I guess you could trap a lot of water in there! And it never feels good taking a VB off in the cold.