View Full Version : Dew vs. a down bag
I'm currently looking to replace a beat up/beat down NF Cat's Eye. I'm trying to keep things light, so I've been looking at the Western Mountaineering Ultralite and some other down bags.
But I'm a little concerned about how down will handle dew. I'd like to sleep under the stars whenever the bugs and weather cooperate, but I don't want to wake up with a damaged bag. Can a down bag handle a light soaking of dew? If not, anyone have suggestions for a good, light synthetic?
Alligator
06-20-2004, 09:46
This Bo doesn't know a lot about down bags, but I think some of them have special layers to handle/prevent light wetting, PERMETEX?. Some folks have discussed TNF Cat's Meow in another thread, it looks like a very good synthetic 20 degree bag. I wouldn't recommend the SD Wild Bill because it does not have a chest baffle. There are some lighter 30-40 degree synthetics. If you were travelling around this time of year, these would be a lighter choice. Choice will depend on location and season.
Toolshed
06-20-2004, 10:18
With the exception of a 45d Polarguard 3-D synth bag I bought for my rainy Alaska trip, all of my bags are down. My oldest is a 1983 EMS Robson -25d and it is still going strong.
I use 40d down bags in the summer as well as the requisite 20d down bags in spring and fall and I like to sleep under the stars when possible, which means dew forming on my bag
My observations:
The newest bags do have better Durable Water Repellancy (DWR) that allows the dew to bead up and run off, but even this wears out after a while (and certainly a good down bag will easily last 20 years if properly cared for) and you will get some moisture entering through the nylon as droplets spread out due to decreased surface tension.
You don't see goretex bags as Goretex material is to heavy to allow the down to loft well (it offsets the theory of moving to a higher fillrate for more loft) it also doesn't allow the bag to breathe and takes forever to dry out if the bags gets damp from inside (perspiration)
Minor dampness from dew will cause little drop in the performance of down - What happens is the moisture spreads out in the down and gradually dissipates - Especially if you pull it out in the sun for an hour as you enjoy a lunch break - If it is an extremely wet dew, you might lose as much as 10-15 degrees in performance due to some loss in loft, but I have never had a noticeable difference, except in deep winter conditions, when moisture (from within) accumulates and then after 3 days in deep freeze your bag weighs another 3 lbs from perspiration (Vapor barrier liners or VBLs come in handy here)
Good luck
Kerosene
06-20-2004, 10:46
DWR treatments and lofting are also compromised by the oils in your hands and body. Western Mountaineering strongly suggests that you periodically treat the bag with Revivex(sp?) which should restore the water repellency (not waterproof). Some other manufacturers build their bags with microfiber shells which are a little heavier but should retain repellency.
At some point you're going to end up going with a down bag if you're serious about cutting weight. Most experienced hikers put a plastic bag inside their waterproof stuffsack, wash the bag periodically (not sure if that's every 2 months or 4 months of use), and are careful about exposing the bag to moisture.
hungryhowie
06-20-2004, 16:05
Down bags are fine. Even standard non-DWR nylon will handle dew, which burns off quickly after the sun rises in most instances. Now-a-days, many manufacturers of down garments and bags use microfibers and materials with excellent breathability but with good water-shedding characteristics. Note that I have older down bags (even homemade ones) with plain-ole ripstop nylon and no DWR that have performed admirably for years.
Geese live in the water, correct? They also live in the water up North, correct? Geese produce oils which coat the down and make it slick to ward off water. These oils are still present when you receive your bag from the manufacturer. With time, these oils will need to be replaced, which is why you should wash your bag with NikWax Down wash and down proof.
With thousands of trail miles in humid/rainy conditions...nearly all of which with down bags, I recommend using down bags in any conditions. I use a silnylon stuff-sac with a trashbag liner. It's quick, easy, and foolproof. This setup allows my bag to stay dry even if fully submerged in water.
-Howie
stranger
06-21-2004, 05:47
As stated earlier many down bags have some water resistance but it depends on what is causing this resistance. If you are depending on a DWR coating, which most bags come with, this will wear off in time and water will then be able to soak into your shell material. This is true of most tafetta nylon shelled bags.
If you are concerned about water it's probably a real good idea to get a bag that uses Dryloft, Dryloft lite, or Epic. These are very water resistant shell fabrics that will not wear out in time like a DWR will. Of course no bag (well one I think from Mtn Hrdwr) is water tight due to needle holes so there is always a risk. I have always used bags with just a tafetta shell and had no problems, but I restore the DWR annually, usually with Tectron.
hungryhowie
06-21-2004, 07:08
If you are concerned about water it's probably a real good idea to get a bag that uses Dryloft, Dryloft lite, or Epic. These are very water resistant shell fabrics that will not wear out in time like a DWR will.
Actually, using fabrics with these technologies is false economy for nearly everyone. While these fabrics are effective at keeping out water...so are they effective at keeping it in. The human body emits about 2 pints of water during an 8-hour sleep. While the vast majority of this comes through the mouth (and therefore would not be exhaled into the bag except in the coldest weather when you cinch the hood completely up), a substantial amount is put out through the skin. Without an ultra-breathable shell, this moisture remains in the bag and can accumulate to a level which begins to cause "limp feather syndrome" unless the bag is aired out to dry in the sun regularly. Having used bags with dryloft and without dryloft, I vastly prefer those that use a microfiber shell that sheds moisture without sacrificing breathability, weight or cost.
As backpackers, we would be far better off carrying adequate shelter for the conditions which we experience on the trail. For me, my 14oz tarp has always done the trick.
-Howie
Having used bags with dryloft and without dryloft, I vastly prefer those that use a microfiber shell that sheds moisture without sacrificing breathability, weight or cost.
So which bags would fit into this category?
I've gone SYNTHETIC...& NEVER looked back.
i own a SD WILD BILL 2.0 Long just under 3lbs (my scales say 2lbs 12oz)
a 20 degree bag that keeps me toasty on all those cold Spring nites in the Smokies! :D
hungryhowie
06-22-2004, 06:54
So which bags would fit into this category?
Nowdays, prettymuch any down bag of quality. Anything manufactured by companies like Marmot, Western Mountaineering, Feathered Freinds, etc. Pertex is a manufacturer of widely used high-quality microfibers. They're certainly the 'brand name' of breathable shell fabrics, but there are many others.
-Howie
stranger
06-24-2004, 06:42
I agree that microfibers are great shell materials, I have a microfiber shelled bag that I've used extensively back in my winter days...unfortunately I cannot handle those temps anymore (-15).
I would disagree that Dryloft doesn't breathe well, but that's my experience. I have a Dryloft bivy that has worked great for me over the years. Of course it will not breathe like a microfiber, but for someone concerned about water I thought I would recommend it as it's far more water resistant.
steve hiker
06-24-2004, 07:08
I would disagree that Dryloft doesn't breathe well, but that's my experience. Of course it will not breathe like a microfiber, but for someone concerned about water I thought I would recommend it as it's far more water resistant.
That's right-o but when my master takes me in the woods in the winter he puts his head all the way down in the down bag and breathes like a steam engine so his bag better be reel breethable else he'll wake up with ice cubes in the feathers. Right-o stranger? :bse
[QUOTE=vggalan] I'm trying to keep things light, so I've been looking at the Western Mountaineering Ultralite and some other down bags.
I think you will be well pleased with the WM Ultralite...I know that I am...Just stuff it in a trash compactor bag inside your pack and use a pack liner for double protection. The 2004 model uses the pertex HH described.
Kerosene
06-24-2004, 08:46
I bought the 20-degree WM Ultralite for my early April Georgia trip this year -- packs small, well under 2 pounds, good feel, not too narrow for my 5'9", 175 pound frame. The temp got down to just below freezing our second night out. I'm pretty sure that I was well fed and hydrated, and I normally sleep pretty warm, but I had every piece of clothing and couldn't get "toasty", unlike my old 15-degree Marmot Pinnacle. I would have gone with a 2-oz overstuff if I could have received the bag on time, but I didn't think it would be a problem at 30 degrees. YMMV; certainly there are many other positive reviews of this bag.
gravityman
06-24-2004, 10:26
I bought the 20-degree WM Ultralite for my early April Georgia trip this year -- packs small, well under 2 pounds, good feel, not too narrow for my 5'9", 175 pound frame. The temp got down to just below freezing our second night out. I'm pretty sure that I was well fed and hydrated, and I normally sleep pretty warm, but I had every piece of clothing and couldn't get "toasty", unlike my old 15-degree Marmot Pinnacle. I would have gone with a 2-oz overstuff if I could have received the bag on time, but I didn't think it would be a problem at 30 degrees. YMMV; certainly there are many other positive reviews of this bag.
First time that I have ever heard anyone say they weren't happy with the ultralight below 30 degrees. My wife and I both have one, and have taken them down to 20 degrees, and ever very toasty.
Everyone is different...
Gravity Man
steve hiker
06-24-2004, 10:29
I had every piece of clothing and couldn't get "toasty", unlike my old 15-degree Marmot Pinnacle.
That's probably why you were cold. All that clothing interferes with the ability of the bag to heat up.
Kerosene
06-24-2004, 18:04
Yes, I was quite surprised that I wasn't warm enough. Again, it sounds like I'm an outlier here. Maybe I'm just getting old???
On other nights I slept with little or no clothing since it was warm, but even so I had to fully zip up to have a chance of staying warm.
One of these days I will compare against another WM Ultralite bag to make sure they're the same. When I first purchased it, I loved its light weight but was disappointed with the loft. Who knows.
gravityman
06-24-2004, 18:29
Yes, I was quite surprised that I wasn't warm enough. Again, it sounds like I'm an outlier here. Maybe I'm just getting old???
On other nights I slept with little or no clothing since it was warm, but even so I had to fully zip up to have a chance of staying warm.
One of these days I will compare against another WM Ultralite bag to make sure they're the same. When I first purchased it, I loved its light weight but was disappointed with the loft. Who knows.
Disappointed with it's loft? There's something going on there... My bag lofts so that it is straining against the baffles. It does take a good shake and a few minutes to get there though. I also have to periodically shift the down back around to the top. I do this by holding the underside zipper side, and giving it a go "whipping" to get the down to move back around.
If you're baffles don't look like they are full, I would call WM and ask them what to do. If it is new, then I would suggest that you ask them if you can send it back and have them check it out to see if it is lofting as much as it should be...
If you insist, I can measure the loft of our 2 bags...
Gravity man
That's probably why you were cold. All that clothing interferes with the ability of the bag to heat up.Just curious: Why would adding layers not keep you warmer?
steve hiker
06-24-2004, 20:27
Just curious: Why would adding layers not keep you warmer?
I don't know, but I sleep warmest wearing nothing or just a thin polypro layer. I think it has something to do with down being a better insulator than cloth. That is, more heat gets into the down with fewer clothes on, and the down traps the heat better.
I bought the 20-degree WM Ultralite for my early April Georgia trip this year -- packs small, well under 2 pounds, good feel, not too narrow for my 5'9", 175 pound frame. The temp got down to just below freezing our second night out. I'm pretty sure that I was well fed and hydrated, and I normally sleep pretty warm, but I had every piece of clothing and couldn't get "toasty", unlike my old 15-degree Marmot Pinnacle. I would have gone with a 2-oz overstuff if I could have received the bag on time, but I didn't think it would be a problem at 30 degrees. YMMV; certainly there are many other positive reviews of this bag.
Don't regret not doing the 2oz overfill as I talked at lenght with WM about this and they stated it MIGHT add 2 degrees as their bags are filled to the max on the baffle campacity of this bag...if going with the wider baffle Megalight it would work. If going with the FF bags ALWAYS order overfill to reach the advertized temperture rating!
I agree that you should contact WM with your disappointment, as it is very rare, and they would be very happy to apease that.
dougmeredith
06-25-2004, 08:15
Just curious: Why would adding layers not keep you warmer?
More insulation will always keep you warmer. The only way wearing clothes inside the bag would *not* keep you warmer would be if the extra bulk compressed the bag and caused a net loss of insulation.
Doug
Youngblood
06-25-2004, 10:03
More insulation will always keep you warmer. The only way wearing clothes inside the bag would *not* keep you warmer would be if the extra bulk compressed the bag and caused a net loss of insulation.
Doug
That is my understanding also, that wearing clothes inside the bag will keep you warmer. (After all, you are trying to 'not lose your body heat'. You are not trying to 'warm the bag'.) Some things that might change that are compressing the insulation of the bag (like you mentioned), the clothes being damp or maybe somehow you introduced convection heat loss. I have ran across situations where people forgot about the zipper draft tube and didn't make sure it was in place over the zipper as well as times where someone's ground pad wasn't providing enough insulation. If I am not warm enough I try to determine where I am getting cold and then see what, if anything, I can do about it. Sometimes all it takes is another layer of socks, plastic bag between layers of socks, a warmer hat, jacket, etc. But Kerosene is an experienced backpacker and I suspect he is well aware of all this.
Youngblood