Companion forum thread to:

Vapor Barrier Liners

Thank you for that article.

It's interesting to compare this to Mike Clelland's description of how he fares on month long outings at sub-zero F temps. I'm not familiar with Michigan or the Rockies, and I wonder if one system is more appropriate for a particular location. Where I am in the PNW in deep winter, I don't feel any need for VBL while on the move (other than socks), but it really works for me when stopped (esp. the featherlite mitts, but not vbl socks - need to air the feet out until I get in the VBL bag).

Unfortunately, it sounds like a wool baselayer does not work as well as synthetic when used in VBLs. I've just discovered merino wool baselayers, and they smell much less worse after a week in them. But they seem to get wet in my VBL, whereas my polypro never did. If anyone knows how to make wool work in a VBL, please let me know any techniques.

Finally, in addition to the manufacturers noted, Feathered Friends makes (made?) a nice VBL bag with a half zip, with snaps to link to an FF sleeping bag.

http://www.featheredfriends.com/accessoriesProductDetails.aspx?ProductID=1&CatID=4&ProductName=Bag%20Liner&SubCatID=34

I wish Andrew had mentioned what specific type of fabric he used when he made his own VBL gear...

He used silnylon.

Excellent, timely article.

I'd like to hear about applicability of VBL clothing for near-freezing rain- which to me has always been the most challenging situation.

Also, what sort of outer shells do you use over VBL clothing? Completely waterproof or do you go with some permeability to allow any moisture that did get in, to get out. (I've had great success with a sleeping bag VBL and the foot of the bag put into a large trash bag to protect the lower 2/3 of the bag from any sort of moisture)

Also, what sort of outer shells do you use over VBL clothing?

James, that is a really good question. I only use a VBL for sleeping and I wear a softshell during the day w/o VBL. But I guess if you were to use a VBL during the day, there would be no point in having a breathable jacket (ie. softshell) because there wouldn't be any moisture to transport out. Perhaps you could get away with an insulation layer and then another waterproof jacket on top? There is some potential to save weight here! I'm interested in what others have been using - and their logic for their system.

Also, when is someone going to make VB clothes at a decent weight? You guys are probably sick of me complaining about this, but everything available is WAY too heavy.

Great article! The best I've seen on this little understood technique. Very clearly stated. I now feel like I have a basic understanding on the theory and application of VB. Thanks BPL and Andy!

Has anyone had any experience using Brynje mesh base layers under a vapor barrier?

I'm super happy with the gloves typically made by workers at Subway when building sandwiches. They weigh nearly nothing and are an excellent glove-vapor-barrier that is free with purchase of sandwich.

Nice article, enjoyed reading.

Some of the early work on VBL's for clothes (but long
after the Korean War VBL boots) was done pre Goretex and
pre poly underwear. They had success with large mesh fishnet
underwear, then VBL, insulating layers, then a coated nylon
parka.

Even cotton fishnet was considered functional with a VBL,
tho wool was preferred.

Stephen,
I wear merino with my VBL and have no issues. Yes, the wool retains a slight bit of moisture. However, I've found that when I crawl out of my VBL sleeping bag liner I can just toss on my overlayers and my body heat dries everything out within twenty minutes or so. It's possible that for multi-week winter trips you could end up with some moisture that doesn't burn off in the outermost layers, but so far so good. I prefer the feel of the wool on my skin. Either way I think it's largely a personal preference and a degree of tolerance in one way or another... Cheers...

Although it's heavier than silnylon, I find the comfort of Stephenson's 'Fuzzy Stuff' to be worth the extra weight. No base layer required, AND it stretches which Andrew pointed out is pretty important if wearing close fitting clothing.

Yes.

I've tried RBH NTS, various polyester base layers of different thicknesses, and the Brynje. I have not tried "Fuzzy Stuff".

IMO, Brynje polypro fishnet is the best I've seen for use with a VB.

If you wear a baselayer under the Fuzzy Stuff, do the two grab at each other reducing flexibility?

Mike said:
"IMO, Brynje polypro fishnet is the best I've seen for use with a VB."

What was the difference between a polyester mesh and the brynje? Seems pretty pricey for a bad 70s fashion flashback. Or is this really some magically wicking fabric?

Is their a MYOG alternative for Brynje?

The Brynje is not wicking -- it's virtually non absorbent and allows sweat to evaporate directly off of your skin where maximum cooling is achieved. With a wicking layer, the sweat is transported outward, reducing skin cooling, but also reducing the rate of evaporation (and increasing moisture buildup) because the outside of a wicking base layer is cooler than the surface of your skin. (Yes, the increased surface area of some wicking baselayer fabrics somewhat mitigates this effect.)

I've done a lot of testing with fishnet over the past winter and have found it to be the best-performing base layer both with VB and conventional layering systems -- especially during high exertion activities such as trail running. It has the highest warmth per weight ratio, best moisture management, and broadest temperature range I've seen.

Getting past the bad fashion is the first step towards enlightenment. ;-)

-Mike

Edited by MikeMartin on 02/18/2009 17:38:25 MST.

Good point about the start stop winter activities but don't write off VBL if you do those activities. On many multiday trips, I have used a VBL sleeping bag liner for warmth and to maintain loft in the bag. But it does make it difficult to get out of bed. It is also important that you do not breathe into the VBL sac. On one Yellowstone winter trip, my bag still had substantial loft while my partner's were flat or soaked. VBL for feet and hands is incredibly effective. I use old VBL booties or plastic bags with a silk liner underneath for comfort. I like dishwashing gloves for VBL with a silk or polypro liner underneath. Dishwashing gloves give you good dexterity so you can keep them on in almost all activities (I will leave that to your imagination). The one thing that I can't do is stand at a belay stance rapidly cooling with VBL on my body. If anyone has found a way, I would like to hear about it.

Nice article Andrew! I became acquainted with the VBL concept back in the 70s after reading a Stephenson's catalog description of their VBL sleeping bag. Couldn't afford the bag so I got a liner and have been using one ever since. Now I think it's time to try the suit as Andrew describes. However, I've noticed that some exercise shops carry a vinyl one-piece suit...I wonder if that would work?

I tried surgical latex gloves under fleece-lined gloves. They work fine as VB, but don't have strength of dish washing gloves.

I experimented with a plastic bag over a light wool dress sock on one foot and only a light wool sock on other foot, walking to work 30 minutes at -35F. There was a noticeable difference in warmth at the end of 30 minutes. I left the bag on inside all day and walked home at the end of the day. It was not terribly uncomfortable and not cold walking home.

On the same walk I wore a vest made from a black garbage bag over 120 light merino wool t-shirt. It was comfortable and I took it off when I arrived at the office.

This week I picked up an interesting book right beside Backpacking Light's "Lightweight Backpacking & Camping"(Edited by Ryan Jordan). The title is "The Snow Walker's Companion".
http://www.amazon.com/Snow-Walkers-Companion-Winter-Camping/dp/0976031337

Although not ultra-lite, their approach to moisture control is different and seems to work well for their extended snowshoe trips. All their foot gear and layered clothing is designed to move the moisture to the outer surface of the outer later of clothing - in some cases a cotton wind garment. They don't use modern "breathable moisture barrier materials" because it does not let moisture pass quickly enough and sometimes results in ice formation inside the outer garment.

Unlike ultra-lite tenting, they use a wood stove in a cotton tent to dry damp sleeping bags. The tent breathes as well and minimizes condensation.

http://www.northwoodsways.com/winter/trail.html

An interesting read. Check the reviews on the website.

George

Thanks Brad - I am going to continue trying the wool in the vbl. Drying out insulating clothes is no problem, the temps in my area in deep winter usually don't go below 5 F in the middle of the day, and slightly damp things dry out in less than half an hour unless it is raining (which can also happen in deep winter here).

The mesh polypro sounds interesting too. My 10 year old LIFA shirt has pilled to the point that it is like a fine mesh, and it is now by far the fastest drying garment I have ever tried.

On another note, Dancing Light made lightweight sylnylon jackets and (I think) pants. I still have one of their jackets, and I tried to use it as vbl clothing one trip. Didn't work at all for me - spent too much time undressing and redressing, the sleeping bag was too tight to allow the down parka to loft, and I didn't have vbl for the lower body. Now Andrew's article has me thinking it over again - sylnylon rain pants and a roomier bag would all I need to complete the system.

Edited by SteveYK on 02/19/2009 00:52:25 MST.