Western Mountaineering on water resistant down and Pertex fabric

[Woubeir (from Europe)]

AFAIK no. From what I remember from one of my biochemistry courses, I think it has something to do with alpha/beta-keratin changing in alpha/beta-keratin due to moisture vapor and a DWR does nothing to prevent that.

[ROBERT TANGEN]

Roger, is a "vapour barrier" similar to the American "vapor barrier"?

[Larry De La Briandais]

va·pour (vpr)
n. & v. Chiefly British
Vapor.

vapour US, vapor [ˈveɪpə]
n
1. (Physics / General Physics) particles of moisture or other substance suspended in air and visible as clouds, smoke, etc.

[Franco Darioli]

Yes in Australia we speak English.
favour, honour, labour, odour, … rumour, saviour, splendour, tumour , vapour
However we can handle terms like stake,cookies,pavement and all of that.

[David Olsen]

"Roger, is a "vapour barrier" similar to the American "vapor barrier"?"

Yes, just with more flourish.

[James holden]

I have camped for 28 days at a stretch with a -20 synthetic bag at 0 degree temps and found myself getting colder each night as
the bag lost it's loft from moisture and compression. We finally ended up adding a synthetic overbag on the next trips.

which is why ive said repeatedly over the years that if you have a synth jacket put it OVER your downbag when sleeping …

and using down under synth is the "ideal" for of moisture management

in winter youre spending the fuel anyways to melt water, might as well do it overnight and warm up your bag … but in the shoulder seasons you generally arent going to boil water every single night … and in those temps a synth bag is much thinner than a -20F one

to put it simply a thin down layer will actually dry FASTER than a much thicker and heavier synth one simply due to the moisture content vs drying area … however a synth layer of roughly the same weight will handle moisture better and provide some insulation when damp … the trick is to have the INSIDE dry, which is not hard with a hawt nalgene

again to reiterate …. its is exceptionally hard, if not impossible to dry very damp sleep system at the limit of its temp rating without the sun … once it gets that way you better pray you have excess insulation somewhere, enough fuel for MANY hawt nalgenes, a fire, or can get out of dodge quickly

a damp synth at its limit will still degrade, but slower, and it provides some insulation when damp (not wet) … and is MUCH easier to dry out even without the sun

ideally you would want a second over layer … something you "sacrifice" but can dry easily enough during the day when walking, or where it doesnt matter if its a bit damp … ie an overbag or synth jacket

if im worried about condensation … i put my jackets over my bag … in the morning i can wear em till the heat dries em out

;)

[Tom Lyons]

In these conditions, a VBL is appropriate.
A VBL prevents moisture build-up in the insulation from body moisture.
But the heat still warms the insulation and bag, and drives humidity out.
If you use a VBL inside the bag, then you can also use a non-breathable VBL bag on the outside too, with impunity. This keeps moisture from condensing on the outside of the bag.

There is nothing new or revolutionary about this idea.
It works.

[peter vacco]

" Found a +20 degree quality down bag was warmer in the long run than a cheap -20 degree synthetic for multiday winter trips."

oh yes. syn insulation seems to work "ok" , but then when you get to the end of it's working range .. not good.
the down on the other hand,s eems to keep getting better as things get colder. like having sombody lighting a flare down there and it gets al warm and good.
i have swam (swum? ) a river and got my down bag so drenched that water was running off it inside. whatever.. i still slept ok fully dressed (was a stinking mess anyway).
this leads me to think that down takes some long term soaking to be really nasty wet (done that too).

as far as overall weight (this being bpL), methinks that by the time you opt for a syn overbag, you're better off with a real tent and a down bag, and living with the odd colder night on occasion.
but, as said above by the time your down is quite drenched, you've got a mofo (he didn't actually say that , but … ) of a problem to dry it sans sun and some heat.
this is where you want a tent.

v.

[Eric Blumensaadt]

Roger,

How do you know that the DWR is merely a surface treatment and has not penetrated the down plumule?

If it has penetrated the plumule than water vapor can't displace it.

This is where the chemical composition of the DWR as well as its method of application can make the difference.

I dunno if the curent down DWRs available can penetrate the down but we need to have a wait-and-see attitude about this.

Mountain Hardware and others need to test the DWR treated down for resistance to vapor over time.

[Roger Caffin]

Hi Eric

> How do you know that the DWR is merely a surface treatment and has not penetrated
> the down plumule?

Once you go from a surface treatment to a volume treatment you are using a huge amount more chemical and the weight rockets sky high. I am assuming that the treatment does not turn 1 kg of down into 2 kg of treated down (as it were).

Also, since I know more than a little about the various forms of keratin (eg wool & feathers), I have some serious reservations about the technical feasibility of a volume treatment. Frankly, I just can't see it.

Cheers

[Woubeir (from Europe)]

Indeed, it is clearly stated several times that there was maximaly a marginal increase in weight.

[HkNewman]

Roger said … …For a start, many have noted that with a good DWR on the surface fabric, it is actually quite hard to get down gear wet.

I guess if you cowboy camp on top of a mountain while it is snowing things may happen, but in my book that is trying for a Darwin Award. Just my opinion.

So perhaps also for a climber belaying (having to stay stationary in freezing rain or slushy snow) or maybe a day hiker sans shelter trying to get back to the car when the temps go down on a rainy late hike. In terms of being inside a "worthy" shelter, Dri-down would seem overkill (at a premium price) vs. present DWR.

[Max Dilthey]

"I just about died one night due to a very wet down sleeping bag, and it took no effort at all to get it that way."

And down fanatics berate the synthetic users…

I use nothing but synthetic sleeping bags and jackets. I don't advertise it too much because it's definitely a minority opinion on BPL. However, I know myself and I know I make mistakes with weather judgements, tarp pitches, or estimations of temperatures. Synthetic gives me room to make mistakes and learn.

On top of that, in a real survival scenario, I have the assurance I'll be warm (to a certain degree). That can make a big difference in my odds of survival.

[Woubeir (from Europe)]

Ofcourse, synthetic is an option, but I have noted that those have a much shorter lifespan, sometimes only a year. And if you think your bag is enough for certain temps, but it isn't anymore … And they aren't necessarily cheap.

[Max Dilthey]

My EMS Solstice 20 was $75. I took it right down to it's rating for two years and probably more than 100 nights, and then replaced it with something lighter, but by caring for it with Down Wash and restoring loft in the dryer with tennis balls, it's still warm and winter-ready. I would trust it right to 20º right now.

My new bag is a MH Ultralamina, which was still cheaper than a down bag. I expect to get years of service.

[Woubeir (from Europe)]

Let's not forget that this site is for everyone on the globe and that prices aren't that low everywhere. E.g. a TNF Cat's Meow costs in the US $179 while in Europe €180 (which is about $240 these days). And don't forget that stores/chains like REI, EMS, MEC, … are very scares over here or even do not exist. I can think of only one cheap-priced chain and their low prices are only on their products (and the quality of those varies).
You thought the US is expensive ? Then certainly don't buy gear in Europe. (And do not forget that ±40 % of our income is first lost on things like taxes).

[David Olsen]

"So perhaps also for a climber belaying (having to stay stationary in freezing rain or slushy snow) or maybe a day hiker sans shelter trying to get back to the car when the temps go down on a rainy late hike. In terms of being inside a "worthy" shelter, Dri-down would seem overkill (at a premium price) vs. present DWR."

That is a great point. Sitting on a ledge in the middle of a grade four slab climb with an ankle deep river pouring in your shoes and everything synthetic looks good. Even then I wouldn't get my bag out of the plastic until the river stopped. Very different than a mobile hiker.

[Max Dilthey]

Call me a skeptic but I kind of doubt that a comparison between US and UK pricing is remotely fair and unbiased. Your sleeping bag's price is influenced by a whole range of variables. it's not cookie-cutter.

U.S. minimum Wage is $7.25/hour, equating to about $15,000/yr for standard 40-hour workweeks. The UK's minimum wage is 25% higher than that at $10.00 per hour, with 38.5hr workweeks, equating to about $20,000 a year.

That's just the bottom…

I know people in the UK are taxed a lot more, but your taxes DO a lot more for you than they do for us. Much more of my tax dollars go into military spending than yours do, which means more of your tax dollars go into civic services, and on top of that, my health insurance comes out of my salary. Yours is included in your taxes.

On top of THAT, my education purchased in the UK would be tens of thousands of dollars cheaper than it was in the United States. I went to a state liberal arts college with my tuition paid for and I still owe $20,000 in student fees for my two degrees.

We can't even look at average salaries. because of the wage disparity in the United States, your lower and middle class take home substantially more of their wages than people living in the U.S. who pay for their own health insurance. Our top 2% most affluent skew our data so greatly, the United States places about ~10-15% higher overall in take-home personal income. But if you look at quality of life, property value, and access to essential services, the UK is ahead.

So, I don't have sympathy. I lived right outside of NYC for years and every single thing around the city is about 20-30% more expensive than stuff around Western Massachusetts. Right down to bottles of water. Why? Because the average wage is higher. Even the wages at the bottom were higher.

Every place is a microcosm. Every town in the world is its own economy. Comparing the two is like apples and oranges.

[Stephen M]

Max,

Tom is in Belgium, I Iived their with work for 3.5 years and it is utter robbery.

[Woubeir (from Europe)]

I don't want to complain over what we pay and what we get back for it (in theory). That's a totally different discussion (political in nature while this is a backpacking forum).

[Max Dilthey]

Ah, but Tom, I posted about enjoying the quality of my synthetic bag and you brought up pricing.

I never even argued that synthetic was a better value, only that the perceived lack of value due to durability was kind of a misnomer, as the synthetic bags reach a level of quality and longevity in line with expectation based on price (in my opinion).

[M B]

The unfortunate reality, is that a down bag should never come close to getting wet. If it does, the user has screwed up. Keeping it dry, is akin to not walking over a cliff.

There are drysacks to keep them in.

There are tents that can weather cat1 hurricanes and sit in 2" water without letting a drop in.

And there are vapor barrier clothing that can be used to even avoid moisture pickup from body in cold conditions.

If it gets wet, its user error in planning, and execution , of a trip.

[James holden]

and yet we have tales of BPLers i assume are quite experienced here getting their down wet at some point on this thread …

most people i suspect get it wet at least once …. then they learn not to … and pray they dont make any mistakes

;)

[Max Dilthey]

That's akin to saying good skiers should never trigger avalanches or be in avalanche-prone areas, so carrying probes and airbags is useless.

There is such a thing as "calculated risk" in backpacking.

You can bring a tarp and run the risk of being soaked in a hurricane, but that margin of risk is so small that it is reasonable to forgo a hurricane-proof tent and stick with a tarp instead.

Even the best backpackers can make mistakes. Situations can always unravel beyond a reasonable expectation of planning. Many of the greatest climbers and alpinists in human history died on mountains.

[M B]

If you make a mistake, you suffer the consequences.

But you try HARD not to make those mistakes that can kill you. At least you should.

If you dont, then you wont be long for this world.

You dont take risks that can kill you lightly. If you do your a fool.

As quite a few people learn every day.

The underlying problem with risk management, is complacency. When someone has done something 1000 times and suffered no bad effects, they become less cautious. If something bad can happen, it eventually WILL given enough chances. Guaranteed.

[Author]

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