"Kept warm by hiking continuously. Rain suit soaked through"
"the only rain suit I had, a silnylon suit "


This was a big mistake. In those conditions you need to stay as dry as possible during the day. There are 3 ways for your rain suit to fail

1. the suit had a leak.
2. The suit didn't breath enough and condensation occurred.
3. It leaked and didn't breath enough.

Silnylon doesn't breath. Yes you can open up vents to get the moisture out. But you need to make sure rain doesn't get past the vents and get you wet. Check your suit carefully for leaks and repair or replace the suit.

My experience growing up in the PNW was that it can be very difficult to vent a waterproof jacket enough to avoid condensation. While event or Polartec Neo Shell would have performed a lot better in terms of condensation. Under heavy exertion there still will be some condensation but that can be managed by slowing down so that the waterproof brathable material catches up, venting the jacket, and or by stoping in a sheltered spot to get out of the rain and dry off.

If you don't want to get a waterproof breathable suit, get a poncho. They breath very well and will prevent the rain from getting though your suit.

"Comfortable night sleep, but found more condensation in bivy than I am used to, particularly between my sleeping pad and sil-nylon floor."

If your pad was inside the bivy, what was between the bottom of the bivy and snow? If the bivy was touching the snow it will be a cold spot in the bivy and condensation is more likely to occur in cold spots. You might have been better off if you pad was between the bivy and the snow. That would provide a thermal brake and hopefully would allow the bivy fabric to stay a bit warmer and reduced the condensation somewhat.

Condensation inside a tent or bivy will occure then the inside temperature reaches the dew point. there are several ways to reduce condensation in a tent or bivy.

1. reduce internal humidity. You can do this by keeping wet items out of the bivy. but you can't tell your body to to stop releasing water. Also venting also carrys away a lot of heat meaning the inside will be colder than it would be if you didn't vent.

2. Vent the tent or bivy so that any excess humidity is swept out quickly. Unfortunately humidity levels cannot drop below the levels outside the ten. So if outside air temperature drops to the dew point air inside the tent or bivy will also drop to the dew point and condensation will occur.

3. increase the inside temperature. If you can keep the inside temperature high enough condensation will be reduced because the warmer air can hold more water vapor. However to do this you need to you need to reduce airflow in and out of the tent. That means closing the vents as much as possible without completely stoping airflow (you still need to get the excess humidity out). Another way to do this is to use hot water bottles or chemical hand warmers inside your bivy to stay warmer.

Edited by Surf on 02/03/2013 23:33:33 MST.

> The diagram I was calling attention to is the one on the left. The text for the
> diagram on the right was stating that the only way to actually push water vapor
> through goretex in cold weather was to greatly increase body temperature (e.g..
> through exertion).
Confusing.

Cheers

Hi Eric

> the illustration is from http://umanitoba.ca/faculties/kinrec/research/media/Cold_Weather_Clothing.pdf
Turns out diagram was being seriously misrepresented. Ah well.

> Giesbrecht, who has intentionally taken his core temp lower—down to 88.2 degrees
Risky. A few can do this, but it is a very good example of "Don't try this at home folks".
I have gone low, but I doubt it was that low. I was carried out as I was a bit rigid.

Cheers

It's amazing how tiny a sliver of temperature range the human body can function well in. It also highlights the amazing capacity for our bodies to regulate it so well.

Great post Ike, provides lots of good food for thought. I've been out in mixed rain/snow plenty of times, but never had freezing rain and -11F within 48 hours. To be blunt, I doubt many/any of the respondents have. Very challenging conditions, not something to be armchair'd on lightly, and I think you did exceptionally well to have been as comfortable as you were.

I've never experimented with sleeping in VBL clothing. It just never seemed appealing. I have been using a 100 g/m Primalift 1 quilt with good DWR fabric as an overbag this winter, with great success. It seems to prevent the accumulation of moisture within the inner, down bag to a substantial degree, and if used properly totally prevents condensation from getting the bag wet. I built mine so I can use it as an insulated poncho, which makes it more multi-use and better justifies the weight and bulk. Moisture inside your sleep system and condensation inside your shelter are going to happen in winter. This overbag system is a lot less fiddly way to deal with these issues than the ideas suggested above.

The other piece of gear which would have been a game changer for you is a wood stove inside the shelter. You'd need a bigger mid, but you could have dried most everything out at night, each night. Seek Outside is working on a heat-only ti wood stove which they claim will be less than a pound all in. If it weighs that much it will, for me, be an always-have item in winter and shoulder seasons.

I had several days last December that were Similiar to your experience though the low temperature was in the teens vs below zero. Echoing what others have said.
1) When it's above freezing reduce the amount of clothing potentially getting wet. I now have a complete lightweight base layer, cap1 that I will wear with a cuben rain suit. Will the base layer be damp, yes. Does it hold much water, no. Also, I agree with Rogers comments about hiking warm. I can go down to freezing with base layer plus cuben. If I stop, then I have to quickly put on insulation.
2) Just below freezing and dry conditions are very straight-forward. Again, I dress cool so that I don't sweat and moderate ins entity to reduce getting moisture.
3) Still colder then I go back to wearing the rain suit as a VBL over base layer and then minimal insulation as need outside.
4) I don't dry anything inside my bivy. No reason to introduce moisture into sleep system.
5) VBL at night. I have had great luck with VBL even when used above freezing. I have found that I sleep much warmer and it has completely eliminated moisture in my quilt. I am still playing to see the warmest temperatures that I can wear a VBL with only a base layer. I suspect that it will be as high as 40-45.

Dave,
I appreciate your suggestions, and even more importantly, the manner in which they were offered.
Thanks

Greg,
I suspect you and I have very similar styles. Thank you for the comments.

+1 Dave

Ike, you did well to make it 4 days through conditions like that without any more damage than a somewhat damp quilt. I imagine that on an hourly basis you were making adjustments and gear/travel decisions that largely worked out great. You seem to be developing solid winter skills and I admire the way you're willing to get out and go for it, even solo in winter. Experience and experimentation go a long way in figuring out how to be comfortable in these conditions.

I have been spending time traveling on the SHT in winter (Minnesota's North Shore, presumed to be similar conditions). Since any given week can have temperature swings like you described (though I haven't seen those swings in a 48-hour period, either), I've decided I need to be prepared to travel in rain as well as frigid cold. For me, this means bringing at least light WPB rain gear along. I've experimented with traveling while wearing VBLs and never found the sweet spot. A base layer, possibly wind shirt and light rain shell is a bit easier for me to figure out: I'm warm enough when i travel, and though I do get damp from sweat, i typically can dry from the inside while i'm on the move. I felt like i would get drenched in VBLs, but that might just be lack of practice. Some of my best practice for cold rain was actually a week in scotland a couple years ago with highs in the 30s-40s and lots of wind/rain. Making sure I was on the cold side while moving kept me from sweating too much. I used an eVent shell for that trip which impressed me.

As you alluded to, a drying fire (or nalgene filled with boiled water) probably could have extended your trip without making any gear changes. That said, I'd be looking for ways to avoid holding my expensive winter bag up to a fire! It seems you bring a remarkably light kit for the conditions you face, so you probably could add back a bit of weight without issue. Most of my trips are 2-3 days, but if/when i do a 4 or 5 night trip i think i'll still bring WPB shells but also bring a 4 oz sil VB sleeping bag liner to prevent loss of loft/weight gain of my bag.

Finally, some conditions are just tough. There are times when there is no shame in just setting up your shelter for an hour or two: make hot drinks, listen to your ipod and let the worst of it pass. I used to guide long paddling trips and judicious use of breaks for bad weather were great for morale without slowing our pace overall. Knowing when to take cover is important.

thanks for all your contributions,

Matt

Of the two WPB laminates I've found eVent is easier to clean the "body frost" off of the back after use. Once the frost is shaken off well the REI Kimtah parka again breathes fairly well.

My GTX PacLite parka just won't release the frost on the back very well and breathes less well in any situation, cold or warm. Both parkas have good DWR, FYI.

Thus, for very cold weather (10 F. of lower) the use of WPB laminates may not be the way to go.

> Thus, for very cold weather (10 F. of lower) the use of WPB laminates may not be
> the way to go.

Agree. I use EPIC (Malibu) fabric for that. Can be very UL.

Cheers

Ike,

I had the same problem in the UP while you were across the border.

This past trip, I took a Gore-Tex bivy in case we ran into wet snow or high winds. The first night was perfect at 15°F and all was good. The next evening I put a hot metal water bottle in the bag to push any moisture out. The increase in loft was noticeable. Went to sleep a couple hours later and I used the bivy shell. The temp was 5°F. Woke up a couple hours later with the loft in my WM 'Antelope' completely saturated. The interior of the bivy sack was frozen solid. I pulled my Paty DAS Parka out, threw it over me and fell back asleep.

I first started out winter camping using a synthetic bag. In college I switched over to a down bag. I've hardly used a tent for winter camping. I believe it mostly unnecessary when a simple tarp will do.

Over the years I have used a Dry-Loft sleeping bag and if it wasn't around 10°F or below it always held a lot of moisture without using a vbl. After three days of use above ten, the loft was shot. The laminate hold to much moisture in. So I sold the bag for a microfiber shelled bag. This bag performed much better but not perfectly.

What I soon discovered was that my body moves a lot of moisture all the time. A ridiculous amount of moisture compared to the guys I usually hike with.

Over the past two decades of tentless winter camping in the Michigan, Canada and out West I have come up with a couple observations.

It doesn't matter what I wear to sleep at night because I am going to push gallons of moisture out and it has to go somewhere.

It's easier to dry a sleeping bag in the sun out west as they actually have consistent sunny days. Michigan... not so much.

Wool is warmer and more comfortable but the new synthetics move moisture better.

The only two options I have come up with for tentless winter trips over three days when temps fluctuate are:

When using a goose-down bag over an extended period a VBL is a must and a Dry-Loft shell is a benefit when going tentless.

A synthetic bag, though not as compressible is far more reliable.

Both of the above options are not favorable. Comes down to the lesser of two evils, I guess.

Good luck.

I was thinking about your trip comments today at work, and realized that being an old timer, we used to use the hot water bottle trick regularly on winter climbing trips. We were always wet, cold, and out for days on end trying to climb something. The best part of our nights was melting snow, and filling nalgene bottles with almost boiling hot water. Two bottles, one at your feet, and one either in your groin, or on your chest, would raise your body core, and about blow you right out of your sleeping bag. We would move them around to warm whatever needed warming. They would literally stay hot until the next morning.
You did really well it sounds like, and with the ability to have a fire, the hot water bottle might help with heat and drying within your sleeping system. I've used VBLs to sleep in in the past, but it was usually in very cold sub zero temps, and your body went thru a sweat, then cool, then regulate kind of phase while wearing them.
Sounds like a killer trip with plenty of great stories for later!

One lesson I learned long ago was to go to sleep slightly cool. Even if I thought it would get cold I would add layers later rather than overheat early. This reduced condensation in my quilt. So...... If you have hot water bottles, won't that increase the amount of perspiration you give off pushing moisture into your sleep system. Seems like it would help early but possibly hurt later. Thoughts?

youre right that you dont want to sweat more ...

the hawt nalgenes assume that your bag is already a bit damp and losing insulative value anyways, and you need to start drying it out ... or you need more heat ... also the more you wrap the nalgene in, the longer it will last and the less immediate heat there will be

which is why its more a bandaid than a solution ... but IMO better than a fire unless you are in a rescue situation ... you dont risk burning the bag

putting a synth layer over the down is the way to go IMO ... as i indicated this would ideally be a synth overbag/quilt ... or even a synth/fleece jacket over the bag ...

i think the main lesson isnt just how to prevent your down from getting wet ... because some experienced people have ended up with damp down regardless of the cause ... but also how to salvage and deal with it once it happens

Greg,
I don't think that the hot water bottles readily pushed clean thru to persperation, but more so they were an avenue to up core temps. While climbing all day, even with paying attention to liquid intake and calorie intake, one typically ends up with a deficit. Couple that with a stop of effort, ie the camp scene, and the temp drop in extremities, and the onset of hypothermia is a given. By boosting the core, it just helped to regulate the energy you were still using to get your body warmed up for the long night ahead. Also, the overall warmth within the clothing shell, and sleep system "shell" helped to push dampness out. I can't remember the technical term for moving the moisture. Isn't there a term for moisture taking the path of easiest movement etc? Using the heat helped facilitate this. We were able to dry out a lot of layers using this kind of heat. It could have been a very viable method if another day, or even two was needed before it was imperative to dry something completely saturated and unable to insulate.
Hard conditions regardless. Many of us old guys still suffer from cold feet from our not the greatest but it was what we had footwear of old! Gives us the chance to tell lies about the good old days! :)

I'm not sure if a nalgene full of boiled water would lead to net removal of moisture from a bag while you are sleeping, but it would if you placed it in the bag for an hour or two before you go to bed. For example, arrive at camp, set up your 'mid and boil your first batch of water. Put the hot water in a nalgene and then place that (possibly inside a dry sack) in your quilt wherever it seems to have lost the most loft. While you are making dinner, taking photos around your campsite, fiddling with the bushbuddy or enjoying a Superior Jack the heat will force some moisture out, hopefully leaving the down quilt dryer/loftier by the time you're ready for bed.

Leaving the hot water in your footbox overnight while you sleep probably won't do more harm than good as long as you remove enough layers elsewhere that you're not sweating more than you need. Plus, there is the added bonus of having lukewarm water to drink in the morning.

Matt

Ike said… “Put on damp base layer bottoms with shell pants on top. Put soaked base layer top on top of R1 top and hiked until warm and dryish, then flipped them and hiked some more. By 11 am, all clothes felt dry and warm to touch…. Slept in baselayers, shell pants, windshirt, and R1. By 3 am, I was noticeably cooler. Over my lower half where the quilt was still in the bivy, ice had formed between the two layers but loft was maintained. Over my torso, where I had pushed back the bivy to promote ventilation, baffles were damp and almost completely collapsed… Back home, quilt once thawed was very damp.”
I’m no expert, but I’m guessing that this is the point of major error. The “baselayers, shell pants, windshirt, and R1” had all been soaked at one time or another, and even though they “felt dry” they almost certainly had lots of moisture still inside them. As bearbreader said: “3. sleep with any damp clothes OUTSIDE the bag.” [BB, do you get inside a pen with bears then breed with them?] You THOUGHT you were following this rule, I think, but the fact your clothes “felt” dry might have fooled you, and this might be the key error.

I have a light layer of insulation in my bivy to help move moisture. It also adds 15 - 20 degrees of warmth. Condensation is less of an issue with this approach. A wood stove in a pyramid does wonders for drying out gear and making you feel warmer. It does add weight but is often worth it. Alternatively, a second skin in a pyramid often adds about 10 degrees and minimizes any condensation problems.

I had an awesome winter season, getting out for trips at least every two weeks. We had some unusual weather this year, with a fairly high percentage of days in the 25-35 F range with mixed precipitation. This gave me ample opportunity to tweak my system, one variable at a time.

At the end of this, I came to a number of conclusions:
1. Condensation is inevitable in cold, high humidity situations (temps 27-35 F with snow on the ground and mixed precipitation).
2. The single most effective management strategy for me was a light synthetic overquilt. Although I've been a happy bivy user (in floorless shelters) for the past 5 years, I have adequately proven to myself that a synthetic overquilt will do a far better job of preserving loft and minimizing moisture in my down than a bivy would under similar conditions. Weighing the down quilt before and after each trip, I was able to limit water weight gain to less than two oz. The shell of the down quilt was never even slightly damp as when using a bivy, and any dampness in the synthetic was far more likely to dry in a breeze, even in subfreezing temperatures. If not, it was easy to isolate from the main quilt when packing.

A few less important observations
3. Lighter quilts and 900 fill down very quickly reveal weaknesses in technique compared to the monster -20F WM bag I used to use.
4. I am very sensitive to people snoring nearby. Snores carry well over snow and ice.
5. Gaps at neck and sleeves on a typical silnylon raincoat diminish its effectiveness as a VBL. Some cinching mechanism is required.
6. If using a bivy, pad on the outside does decrease condensation on the bivy floor compared to pad on the inside.
7. For a tossing and turning sleeper, getting clothing to stay put on top of your quilt is an exercise in frustration, particularly when all your insulation pieces are pullovers.
8. Hot water bottles might help in a crisis, but shouldn't be needed if you have a sleep system that works well.
9. Using the synthetic overquilt over a down quilt inside a bivy protected the quilt but still resulted in more condensation than when no bivy was used.

Thanks to everyone for the feedback. The overquilt idea was a simple, practical, and lightweight solution to my problem. Hopefully this will contribute a very small piece to the Steven's question "Is there a consensus on the ideal temperature and precipitation range of a water-resistant breathable silnylon-type bivy?" I'll continue to use mine for 3 season use, particularly when opportunity for drying during the day is likely, but can not justify bringing it on multiday winter trips anymore.

Edited by Ike on 04/03/2013 13:16:47 MDT.

Hey Ike,

I was toying with the idea of a synthetic overquilt myself this year, do you take ear plugs on your trips?