Synthetic Vs. Down

7:15 p.m. on September 12, 2006 (EDT)
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I've heard good things about Synthetics: Cheaper and when wet they keep they're rating and dry easy.

Down bags are lighter more compressable and last longer. But are more expensive and are useless once wet and don't dry out easy.

I've been using a Synthetic bag but i'm going to replace it soon. So i'm open to suggestions/opinons.

12:52 a.m. on September 13, 2006 (EDT)
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Look down this board and you will see extensive discussions of this trade-off. The answer is that it depends on how you are going to use the bag. Down is superior for many applications, synthetics (which vary a lot from one another) for many other applications. Lots of trade-offs between the two. You need to specify what your uses will be - summer dry season backpacking, wet winter, rainy areas, cold dry winter, river running, cost considerations, in a tent or not, etc etc etc.

1:46 p.m. on September 13, 2006 (EDT)
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I used a synthetic bag for all of the standard reasons for many years. A couple of years ago I switched to down and never looked back. You can mitigate the useless when wet notion by using synthetic clothes. If your bag gets wet you will likely have enough warmth to keep from freezing to death.

7:13 p.m. on September 13, 2006 (EDT)
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I'm in agreement with Alan. I was a die hard synthetic bag owner, bought my first down bag and never want to use anything else.

My down bag is a MountainSmith (Wisp or Vision, I forget which). Weighs 1.75 lbs and rated at 15 degrees.

I also have a Marmot Merlin Polarguard 3D bag Rated at 0 degrees and weighs about four pounds. I haven't used that bag in a lonnng time.

Don't get your down bag wet - invest in a good waterproof stuff sack. Put the bag in a trash bag and then into the stuff sack.

11:22 p.m. on September 13, 2006 (EDT)
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For a long time I used synthetic so I wouldn't have to worry about moisture problems. I will still use synthetic when that is a significant risk (no matter how waterproof your bag or tent is, you will inevitably have water issues at the worst time).

But for summer use in the Sierra, where it is normally dry, I got a down bag earlier this year, a Western Mountaineering Summerlite. Rated to 32 (and that is conservative, I have used it down into the high 20s without any trouble), and it weighs only 1lb 3oz.

6:09 p.m. on September 14, 2006 (EDT)
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You guys did not really answer his question - in essence, he asked about the trades. Just saying "I used to use synth, but now I have learned to use down in all conditions" is not the answer. Give him some hints on how to keep down dry in wet snow conditions, pouring rain where you get into the tent from the downpour, and other challenging wet conditions (be sure to define "wet conditions"). Note that you are all experienced campers of long experience. Maybe he (or other possible readers) is not. A question for the OP - have you camped in very wet conditions? If so, did you keep your bag dry? If you did, then you are ready for a down bag. If you got your bag damp (not even soaked), you need some more experience and mentoring in wet conditions. (or you can learn "on the job")

I agree that when you keep your down bag dry, down is the way to go (I use down almost exclusively, as I have said). But I have seen far too many people get their down bags (and synth bags, too for that matter) sopping wet and end up wet, cold, and miserable, in weather that I was bone dry.

So guys, give him some real techniques, not just bragging on how good you are at staying dry.

I am headed into the backcountry for a week or so and the weather here (I am on a borrowed internet connection, far from home) is very threatening (thunderstorms today, and tomorrow looks like more of the same, as we head back in). Looks like we will be testing our lightning skills, too.

8:37 p.m. on September 14, 2006 (EDT)
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I backpack mostly in the Smokies and surrounding areas. It rains a lot. I use a down bag.

Pack your bag in a dry bag. I'm not talking about the heavy duty kind used for canoeing and rafting. Outdoor Research makes some nice ones (Hydrolite), as does Sea to Summit (Ultra-sil).

Be careful how you pack your pack. Make sure all liquid container lids are tight. Make sure if things leak they will not get your bag (even dry bags can leak through if left for extended periods in a puddle). Last March, hiking in snow/rain, my bag stayed dry - even though the lid on my Dromlite bag was not tight and leaked out inside my pack. I discovered this late in the day. I was lucky, the bag was positioned such that it was not in the puddle.

Dry your tent if it gets wet while setting up in the rain. A Packtowel works. Don't set your bag down in a puddle.

Use a storm proof shelter. I have stayed nice and dry through heavy downpours, while others in the party, who saved a bundle of money on their tent, were literally floating on their sleeping pads in their tent. I have stayed dry through 44 continuous hours of rain (tropical storm), due to a good tent.

Don't get a tent so storm proof that it does not breathe, or you will still get wet.

Good common sense goes a long way towards keeping your bag dry. These are good ideas for synthetic bags as well. A wet bag is no fun.

1:02 p.m. on September 15, 2006 (EDT)
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Good point Bill. When I bought my down bag I also bought one of the sealed stuff sacks from Granite Gear, Outdoor Research also makes them. That should keep the bag dry while in my pack. I live in Minnesota and mainly camp in Minnesota, Wisconsin and northern Michigan. We rarely get heavy rains that last long, if it rains all day it is generally lighter.

Air your bag out every morning if possible. Also each morning squeeze out the warm, moist air out of the bag. Use a plastic ground cloth inside your tent. Stake out the tent fly everywhere possible to keep the fly from sagging against the tent body. Where the two pieces of fabric touch, water will condense on the inside of the tent, your bag will rub up against the wet spot and get damp on the outside. None of this is rocket science, but a little care goes a long way.

The only time I got a bag wet, thankfully synthetic at the time, was during an unplanned open air bivy at 9000' on Mt. Ranier on my NOLS course. Winds shredded, literally, our expedition dome tents, rain was blowing horizontally, and we had to just hunker down until dawn. A very long night. Interestingly enough, the only shelter to stay up all night was a low-tech megamid. Our instructors both said they had not seen a storm that bad outside of Denali. I guess I got my money's worth on that trip.

3:45 p.m. on September 16, 2006 (EDT)
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Thanks for the advice.

4:37 p.m. on September 16, 2006 (EDT)
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Another way to keep your bag dry is to put it in a bivy sack. I have a Bibler Winter Bivy, which won't keep a bag dry in direct pouring rain, since it is made from Epic-a water resistant, not totally waterproof fabric, and will eventually wet out, but inside a tent, or under a tarp shelter it should work fine. The Bibler weighs about 9 oz. and packs to the size of a soda can. It also keeps the bag clean.

3:18 p.m. on October 17, 2006 (EDT)

I know this post is from a month ago but i think you missed a few points. First off it is a known fact that Down has a higher warmth to weight ratio than does synthetic fillings. It is also known that down is very ineficient when wet.
So in getting a down bag you are saving on weight, but most of you included a few "extras" you bring to prevent your down bag from getting wet. You have to remember these prevenative measures add weight as well further reducing the warmth/weight ratio of your bag.
My $.02 would be that it all depends on the environment you are going to be in. Rainy tropical climates would urge you to bring synthetic while in very cold winter climats down would be more suitable. One thing to look for in a down bag is a waterproof shell. My mountaineering down bag is constructed of a water repellent (not water proof) shell that helps protect the down against moisture such as condensation, miner spills and precipitation.

5:31 p.m. on October 17, 2006 (EDT)
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Ian -
As noted in a previous similar thread here, a waterproof shell has the problem that it allows (actually, promotes) condensation of body moisture on the inside of the outer shell of the bag, thus collecting the moisture in the down. This also happens in waterproof bivy sacks. In part, this is why Steiger's North Pole ski and dog sled trip found they gained about a pound a day in their sleeping bags, so that by the time they reached the Pole, they had 75 pound bags that could not be stuffed for carrying (they had to strap the "boards" onto the tops of the sleds).

Waterproof/breathable shells are better. By personal experience, I found that Goretex and the more breathable version DriLoft do not breathe well enough in Arctic conditions (or even Sierra and Tetons winter conditions), allowing accumulation of a fair amount of moisture (people sweat off about a pint of water overnight and breathe out an additional pint). Microfiber, such as Pertex, is water repellent, eVent (wp/b), and Epic (wp/b) shed spills well enough, yet breathe well enough to not accumulate much moisture in the down in cold conditions. Synthetic is necessary for a fill in above-freezing, humid, or outright wet conditions, with a water repellent or wp/b shell. Or just use it in a tent or wp/b bivy sack.

In really cold conditions, meaning below about 20F, you need lots of breathability to vent the sweated-off moisture (or use a VBL), to prevent the condensation and build-up in the insulation fill of the bag (down or synthetic, either one). My statement is based, not just on reading about Steiger and crew, but on personal experience in the Alaska Range, and winter treks in the Cascades, Rockies, Tetons, Sierra, NH Whites, and elsewhere, with temperatures down to and below -40 deg. You won't notice it on trips less than 3 or 4 days perhaps, but you sure do on trips of a week or more, with month-long trips really showing whether you know how to prevent the moisture buildup.

To emphasize, in really damp conditions, whether wet snow above 20F or rainy conditions, you will still need a tent or bivy sack to keep your bag dry and warm. So you will still have the weight of that cover in addition to your sleeping bag as long as there are damp conditions.

2:19 p.m. on November 13, 2006 (EST)
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Interesting thread. I have an old North Face down mummy (cats something or other I think)which I've had for many years - it was rated to 20F - for me (I sleep hot) it's good down to about 5 (wearing DRY polypro and a balaclava inside it, under a tarp, pitched tight to the ground and on a thermarest).
Moisture does accumulate night to night - however - if you air your sleeping bag out once in a while (like place it inside out on top of your tent - or string it up inside out where it'll catch some wind) you can mitigate the moisture accumulation. Inverting the bag is important - the liner is typically less robust than the outter shell - and allows for moisture transfer to happen faster.
Keeping down clean is essential also - it's really important to wash a down bag with the appropriate soap - to dry it - to make sure any clumps are broken up - and to store it unpacked. Being natural fibers, down pods are more apt to be ruined if you store the bag stuffed tight.
Keeping a bag dry on the trail - well - if you use an external frame pack - dont' dangle your sleeping bag under the main pack bag where it'll sit on the cold, wet ground everytime you unshoulder your pack - I tend to keep mine inside the bottom compartment of the pack. I understand that many internal frame packs have special lower pockets for this - lining them with a really strong plastic bag before shoving the sleeping bag in would seem like a great idea.
I'm not a tent guy - I'm a tarp guy - so site selection is something I really pay attention to. Because of this I cannot recall being "swamped" - I do - however - carry a standard trash bag - to shove the foot section of my sleeping bag into if there's the slightest chance that I'm going to wiggle out from under my tarp during the night. When I'm in camp - and it's raining - and I'm NOT in my sleeping bag - the bag goes into that trash bag during the day - so it won't get wet while I'm changing clothes or thrashing around for some other idiotic reason.
I backpack mostly in Maryland/PA/New York - so I hit a lot of rain -
Sometimes I think that a synthetic bag would be less irritation - I mean getting wet would be one less thing to worry about - and my down has lost some loft over the years - the shell is patched with rip-stop tape here and there - my son has a nice synthetic bag (an EMS labeled one) - he swears by it - has been soaked and "slept" it dry (something I could never do with down) - maybe I'm just a creature of habit ....
well, anyhow, there's my (wandering) 2cents worth -


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