850 or 950 for a winter bag

I’m a cheapo…. 850 for me and no regrets.

I believe Ryan Jordan put forth the idea that really high loft down (e.g. 950) may be more susceptible to moisture, and thus provide little real world advantage. I think this was in a SUL article a couple years ago, which was the first I’d heard of it. I don’t think RJ presented any evidence for this, just suggested the possibility. And to be clear, the idea was that 950 down would still be better than 850 in high humidity, it would just have a smaller advantage, as it might drop to 850, while 850 down drops to 800 etc, and thus be a relatively expensive way to save a little weight.

It’s worth noting that 950 down isn’t some extra fragile down cluster, but rather a higher proportion of down clusters rather than feathers. 800-850 down is about 10% feathers, whereas 950 down uses better sorting to get closer to 0% feathers. So susceptibility to humidity might increase at higher fill powers – this seems reasonable in theory – but the same argument could be used to argue for 700 over 800, or skipping down entirely and just bringing a 100% feather bag.  Really all that’s being said here is that feathers outperform down clusters in mega wet conditions, which may be true but without knowing how important this is in the real world, we can’t know if the ideal amount of feathers is 100%, 50%, 10% or 0%.

So we need to know if any correlation between loft loss and fill power is meaningful in the field. Based on my experiences using 800-900 down bags/quilts, I suspect any difference in resistance to humidity is trivial. I don’t notice 900fp quilts lose more loft than 800 quilts. And I virtually never have any issues with losing loft in general, even in winter conditions in the PNW where I live. Admittedly this is a crude analysis and I’d love to see a quality BPL on article, but I am confident the ideal amount of feathers is close to 0%. I think packing feathers intentionally is just another form of packing fears. Arguments about loft loss in wet/humid conditions have always seemed like paranoia to me, unless you’re the kind of hiker that is grossly irresponsible with your gear.

Also, I have heard that the advent of treated down has really changed the situation. I spoke with Tim from EE recently and asked him this exact question. He said that even if this was true for regular down, it would be much less true for treated down because it’s far less susceptible to humidity. So treated 950, which is the OP is considering, should certainly provide a sustained advantage over 850 in any humidity you’re likely to encounter in the field.

Loft aside, 950 has other advantages. Since there are much fewer feathers, you’re much less likely to get feathers poking out of the bag. And it will pack smaller. So my take is that the loft advantage of 950 does translate into the field, especially with treated down, and it’s the best way to go if you can afford it. Whether this is a wise purchase depends on your finances and where you’re at in your lightweight journey. Many hikers will could find more effective ways to save weight, but down quilts do last for a very long time so if you pony up for 950, you’ll get a smaller packing, lighter and less feather loss prone quilt for decades.

This month I received a backordered LL Bean -20 F. down bag with 750 fill. My WM Megalite 3 season bag has 800 fill so is nearly the same.

Yes , a 750 fill winter bag will not compress as much as an 850 or even 950 fill bag but for $269. (limited sale price) I’m very happy with a bag that is better constructed than an Eddie Bauer 850 bag I returned for a very poorly designed collar. My LL Bean winter bag came with a $419. price tag on it so I know it was a legitimate sale.

The 750 fill beneath me will not compress as much as  a bag higher fill down and that may be a good thing on sub zero nights. :o)

The important thing in my LL Bean winter bag is that the down is DWR treated with Down Tek to keep the down much drier (and the bag warmer) over a week long trip.

Eric B.

take it as you will …

Ryan Jordan
( ryan – BPL STAFF – M)

The kicker is that we ran the same test next to down taken from a manufacturer’s 750 fp bag. at 50% humidity, the fp was 720. Why? It had more feathers that were stiff enough to preserve the loft in moist conditions.

https://backpackinglight.com/forums/topic/39920/

other folks have posted research saying theres no real effect of humidity ..

though i think no one would argue that if a bag got significant condensation (actual moisture) the down would be affected

to further muddy the waters … DWR down might make it a relative non issue

;)

The IDFL steam treatment was developed solely for marketing purposes. If you get your down tested at IDFL you can claim a higher fill power. The IDFL tests and numbers are usually ignored by any European mfr, as they are crap.

Cheers

serge …

as long as you can worship the sun god itll be fine … and i suspect that EEs DWR down will help out as well

i had an EB DWR down vest which ive since given away to a family member … when i used it in the rain it got damp of course, but once it stopped raining it dried out quite well with body heat … not quite synth, but milder dampness it worked quite fine

my favorite climbing partner had a marmot xenon DWR down which she used in the canadian rockies last year where amazingly it rained for a week straight … the DWR down did its job managing the condensation even though there was little sun

there was a series of articles on packrafting in BPL where they used some EE DWR down in damp conditions as they mentioned in the comments

fabric makes a large difference as you noted as well … years ago BPL did a test which some folks use to try to prove that down dries faster than synth … what they forget to say as well is that it was in warm conditions (not cold rain) … and that it was really the WM flash that dried faster because it had a more permeable fabric as BPL noted in the article …

the MB with much less permeable fabric dried quite a bit slower

;)

Roger, I beg to differ with you on the significance of  “down DWR”. I think you need to give DWR treated down a fair trail. I’ve found that it is very useful for retaining loft in down garments in damp weather and sweaty climbs. Soon I’ll find how well it works in my -20 F. winter bag.

All this “fill power” sleight-of-hand by marketers shows yet again how important a good down DWR treatment can be in real world situations. Retaining loft in actual use over many days in less than ideal conditions, such as cold and/or damp weather, is more important than initial loft in dry conditions.

SO… which down DWR,  Dri Down, Down Tek or Patagucci’s proprietary down DWR version will be proven to be the the best and most durable? Or will another new advancement down DWR prove to be “the one”?

Hi Eric

We will have to differ here. For a start, wearing down on a ‘sweaty climb’ strikes me as being fundamentally wrong.

But the whole ‘retaining loft’ idea is also wrong. Down comes from ducks (and geese etc). In its natural environment (on a duck’s body) it is NOT ‘dry’. Down can retain loft while holding a moderate humidity. What ducks do to control the dampness of their insulating down is to protect it with a layer of water-repellant outer feathers. Fine – so what we need to do is to protect the down with a good outer fabric – a water-repellant fabric.
A really amusing thing you can try is to take a bag of down (assuming a good fabric), dunk it in a bucket of water for a moment, then haul it out and see what has happened. IF it was a good fabric, you will find the down remains dry: only the outer surface of the fabric gets wet.
A lot of very technical down gear mfrs have publically said that they will pass on the DWR idea. They can’t see any benefit.

Basically, the DWR is either ineffectual (far too little coating to do anything), OR it makes the down far too heavy. In other words, it is a great bit of marketing spin with very little real justification – a bit like Nike’s arch supports. To be sure, the quality of the down matters, but too many people pay far too little attention to the fabric on the surface. In part that is because the mfrs of down gear keep fairly quiet about the fabric they use – and which in many cases is their own custom material. It’s their ‘secret sauce’.

Cheers

DFL has received over 1,000 samples for DWR testing. The samples include different treatments from
different suppliers using different application procedures and varying qualities of down.

DWR data has yielded many surprising results:

• Natural down is very hydrophobic without treatments.
• Untreated down averages 22 minutes of shaking until failure.
• Some DWR material has yielded over 1000 minutes of shaking before failure.
• Polyester did much worse than expected in absorption rates and hydrophobic shake testing.
• Polyester and other synthetics can also be treated with DWR. In some cases, the results show
great improvement in hydrophobicity for polyester fillings.

IDFL’s research on down performance before and after DWR treatment:

• More than 50% of DWR treatments have a positive effect on Fill Power.
• Generally, the DWR treatments slightly increase down cluster percent and decrease fiber percent.
• The oil & fat content percent increases by an average of 0.6% after DWR treatments.
• DWR treatments slightly improve the cleanliness test results of down and feathers.

http://www.idfl.com/media/pdfs/IDFL%20DWR%20Info%20Sept%202014.pdf

I agree with Roger. The big deal about down warmth is staying dry. Iff I let my down bag get that wet, I will have more trouble than just being wet. And it doesn’t really matter whether it is treated or not…it’s wet. At cold temps, it doesn’t make any difference because it would never get all that wet. It would be snow. Nor will DWR coatings of any type stop condensation/ice build-up in your down bag. Based on experience, at around 25F and above, wet stuff becomes a significant concern. But, I would not subject my bag to a water bath in the first place. Hell, I go out of my way to AVOID wet spots. Again, the IDFL is testing stuff, getting results, reporting it, but, it has nothing to do with the objective of camping. Who cares? I would not sleep in a mud puddle anyway, soo, why would I care how long it takes to wet out? Real World Conditions. Sorry, the test is interesting but mostly meaningless in our context. The only difference would be how long it takes to dry the next day. Sorry, I suspect I would be of little concern by then.