Down Gear in Scottish “Winter Conditions”

by on February 28, 2006

No, I haven’t been in Scotland.

But it felt like it.

Carol Crooker, Aubrin Heinrichs, and I just spent three days in the Specimen Creek drainage in Yellowstone National Park. We spent last night at Sedge Lake.

When we left, the weather was forecast for lows near 10 degrees – perfect winter conditions. Instead, we awoke this morning to temperatures that were exactly 32 degrees in my Epic tent and overnight snowfall of nearly a foot of heavy crud.Img_6469

After two nights of this, it became clear that any gear – whether down or synthetic – is going to fail. It’s just a matter of when, and time zero starts at the trailhead.

Just for kicks, we weighed our bags and measured their loft when we got back into town tonight.

Carol was using a Valandre Shocking Blue, which lost almost 20% of its loft for a weight gain of water of around 10%. I was using an Arc X, which only weighs a pound dry, gained 25% of its weight in water (interestingly, about the same weight gain as the Shocking Blue – 4 oz or so), but with far less down to buffer the effect, lost an amazing 80% of its loft.

Neither bag was particularly “flat” this morning – we speculate that the primary mechanism by which so much loft is lost is during packing – stuffing a bag with moisture on its shell into a stuff sack, causing that moisture to migrate into the insulation.

In these conditions, synthetic will delay failure, but not necessarily prevent it. My synthetic jacket, a MontBell Thermawrap Parka, which I wore in camp and on the trail at rest while it was snowing/slushing, gained about 25% of its weight as well, but lost less than 10% of its loft.

And so, if you’re heading out into winter crap, which is about the only term that describes “temperatures near freezing with sustained heavy snow and rain and no opportunity to dry gear”, follow these rules:

1. Down won’t work. Don’t even try to make it work. No waterproof-breathable fabric bivy sack or tent will help. No super breathable system (think: tarp, no bivy) will help. At these temperatures, the dew point will be inside the bag and any moisture in your shelter (bivy, tent, tarp, snow cave, it doesn’t matter) will condense on the outer fabric. You’ll pack your wet bag into a stuff sack in the morning and enjoy the beginning of an absolutely awful night when you unpack it that evening.

2. Synthetics won’t work either. But they at least will allow you to spend an extra night or two.

My pick for shelter and sleep systems:

If you like a double wall tent, use one with NO mesh in the inner tent, so condensation can readily pass through its fabric. Or, a single wall tent made of eVENT. Gore-Tex and Epic tents fail miserably at temperatures near freezing when the humidity is high. Tarps should offer protection from blowing snow. Pyramid-type shelters are popular but vent moisture poorly. Standard tarps let in a lot of spindrift. If using the latter, you best have a bivy of some sort – I recommend eVENT. Pair any of these options with a synthetic sleeping bag with synthetic fill parka and pants, and even in the worst of conditions (sustained), you should be able to buy yourself enough warmth for a 5 or 6 day trek.

  • Kevin Davidson

    Well, since singlewall eVENT tents are no longer available in N. America, that reduces the proposed tent options in half.
    Curious about other factors present. Were any vents open on your Epic tent? Was there any wind?
    I’ve not tried this in these conditions, just musing— what about using VB inside the bag ( I know, far to warm to use it as it is normally used) to move the dew point outside the sleeping bag and accept the sauna like conditions within. Idea is to perhaps be uncomfortable ( w/ sopping wet baselayer) but warm (?) and insulation preserved. And praying all the way that temperatures move downwards.
    These conditions really suck.

  • http://www.wildebeat.net/ Steve Sergeant

    Sometimes, the physics are not in your favor — a person just doesn’t generate enough BTUs to vaporize all of that water by themselves.
    If the group was large enough to share the weight, it’s times like these when I’d advocate one of the tents or teepees with a wood burning stove, such as those made by Kifaru [ http://www.kifaru.net/TIPI.HTM ] or Titanium Goat [ http://www.titaniumgoat.com/tents.html ] (among others). These aren’t ultra-light, especially with the stove, but I actually think (without doing the math at the moment) that these would save weight vs. lot of other redundant gear you might otherwise carry to protect against these conditions.
    Nothing beats actually being able to dry out your gear.

  • JNDavis

    Did you hear Hamish Brown’s story about a trip taken when very young, relying on wool, including blankets. They survived a downpour. On reaching home, tent, blankets, jackets etc. were thrown into a big pile and weighed. The gain was 10 pounds per person – a British gallon each! Thank heavens for modern fabrics.
    By the way, I do use down in Scotland, throughout the year. Some nights do reach 100% humidity – I have pitched in clouds – but the weather is very changeable, so most nights clothes and bedding dry with body heat.

  • Graeme Finley

    Given the supposition that most of the moisture was beaded on the shell (and therefore got pushed into the insulation when the bag was packed) how realistic would it be to delay serious loft loss by manually drying the shell with an absorbant cloth before packing? The question then may become how you dry the cloth, but that would be an easier proposition than a sleeping bag.

  • gwelker

    The weather you describe is actually pretty typical weather for the midatlantic area where I spend a lot of my time. 30-40% humidty with snow fall is not uncommon, with temps in the 25-25 range many days during winter.
    Bivy bags don’t seem to work – you need maximum moisture movement. Backpacking candle units work well to drive the moisture out of a double wall tent, just be careful. Down works, but be careful not to sweat in it – I hike in polartec and fleece layers, then use down jacket and bag in camp. Carry the down bag in a drybag (a real one), pack it up as soon as you get out of it in the morning, and when in it at night keep yourself cool enough that you don’t sweat in the bag.
    Actually hammocking works well – keeps you off the wet ground, adds another side for convection to get rid of water vapor, and the temps aren’t too low for the winter hammock arrangements, which can be pretty lightweight.

  • http://www.ecotrend.org.uk/trek Andy Howell

    Being a UK hiker I’ve spent a lot of time camping in these kind of conditions. In general my down bag copes well with the conditions. Over the New Year period I was camping every night in sub zero temperatures. In the mornings there was often condensation inside the inner tent of my Hilleberg Nallo, indeed on some mornings thta has been turned to ice. My bag – a Rab Quantum 400 with Pertex fabric – remained fine. Only one one night was I cold but that was when the termperature dropped to -10 which is a bit below what the bag can cope with.
    When camping in these conditions it is important to maintain the ventilation in the tent and in the mornings it is a good idea to give it a good airing. The pertex on the sleeping bag always dried out and the down remained un-touched.

  • Roger Caffin

    Sounds absolutely standard for the Australian ski fields when it’s overcast.
    But we have few problems with down gear for up to a week, provided we take some care.
    We use a full double-skin tunnel tent for this: a waterproof fly and a DWR-treated parachute fabric inner. None of these tarps or condensation-trap domes thank you.
    We have through ventilation at the top of the roof IF there’s any breeze. We only block the windward end of the inner tent in seriously bad weather (think driving snow and spindrift).
    We sleep two in the tent (my wife and me), and the extra heat does help keep the inner tent above the dew point. Sleeping solo under these conditions is a big mistake imho.
    We don’t sleep too warm and sweat.
    Of course, if it turns out to be way sub-freezing, we may end up with hoar-frost on the inside of the inner tent, but not on the SBs.

  • Don Kolstad

    Even after growing up in Chicago and later living in Montana running a survivial school I only use down bags in all humidity conditions to the surprise of most people I meet: in Alaska’s Glacier Bay kayaking and hiking for over a month or the Queen Charlotte Islands for another damp month or two in heavy rain and cool temps under 40F; Bike touring the Divide from Canada to Mexico; Norway and other damp garden spots I have learned a few things.
    What has worked best for me for the last fifteen years to preserve down loft and to even dry out wet or damp gear has been Stephenson’s Warmlite Fuzzy Stuff VBL clothes. Aside from the above benefits I find that I can bring fewer clothes and use a lighter bag or quilt due to the warmth factor of the vbl. The lack of clamminess and odor reduction are real bonuses as well in my experience.
    Before finding the Warmlite clothes I had tried about every vbl over the years without success from the late 60′s onward-Synergy Works, Chouinard, Western Mountaineering and Feathered Friends to name a few.
    I know that Dr. Jordan is not a fan of vbls but his dismissal of the genre out of hand with what seemed like expressed limited experience with them has caused him to miss the benefits of an excellent and inexpensive piece of gear that is also a great backup as survival gear.
    Don Kolstad

  • Iceman

    “If you like a double wall tent, use one with NO mesh in the inner tent, so condensation can readily pass through its fabric.”
    I would think that it would be easier for condensation to pass through the mesh.

  • geoffrey winthrop young

    I used a VBL with a down bag night at about 5F and was surprised how much loft was preserved in the bag at the morning stuffing session, compared with similar nights sans VBL. But my several experiments with VBLs ended many years ago and I’ve drawn very few conclusions.

  • http://www.bymmo.com ffxiv gil

    I used a VBL with a down bag night at about 5F and was surprised how much loft was preserved in the bag at the morning stuffing session, compared with similar nights sans VBL. But my several experiments with VBLs ended many years ago and I’ve drawn very few conclusions.