Down vs synthetic sleeping bag for thru hike

[Walkintom]

Is anyone here who uses a down bag allergic to down?I'm not allergic but my wife is and I am curious as to whether I could get away with a down bag. I have a decent but not great synthetic now,

[Carl Calson]

i was caught in a rainstorm in the smokies on easter break this year and, without a rain cover for my pack, my sleeping bag got drenched. luckily for me, it was synthetic. i dried it over the fire for a while but didn't get it completely dry, slept in it anyway, and was comfortable all night long.

then i bought a down bag and a sea to summit dry sack, and don't worry about it anymore.

[Tinker]

Use heavy wool blankets and lots of them. Hey, it worked for the cowboys, didn't it?

Down. It will be as warm when you finish as when you started (unless you use a compression sack and crush the plumules of down to death).

Synthetic. It will lose loft slowly as you pack and unpack it. The fibers are given a crimp in a heated environment to make them spring back when compressed. Think of it as a "perm". When repeatedly stuffed, this "perm" relaxes, and, just as with hair, straight synthetic insulation fibers take up less space than curly ones. Less dead air space in the bag means less trapped air (also called loft) which results in a colder bag. The weight will not decrease, unfortunately.
Leave the bag in a hot trunk in its stuffsack (or worse, a compression sack), and the fibers will get soft and lose their crimp prematurely.
Dry your wet synthetic bag in a hot dryer and you could ruin it in half an hour (I did that once, myself).

My recommendation? Get a good down bag and keep it dry. It will last for years.
OR: Get a synthetic bag, saving money,carry more weight and bulk, necessitating a bigger pack, worry less about water, and plan on replacing your bag after your hike or, possibly, once it gets cold again, before your hike is over.
OH- Once you try a down bag and feel how it snuggles around you, keeping every nook and cranny of your body warm, any synthetic bag will feel like a bag with house insulation in it.

[Ladytrekker]

My Montbell super spiral 15 degree down was the purchase I have ever made. Light, roomy and warm.

[Echraide]

there's no reason a down bag should get wet.

Splashup is one reason.

[SassyWindsor]

Wow, just got the best xmas present ever, a new Western Mountaineering Puma w/gore wind-stopper. Had been concerned about an upcoming winter outing and if my old WM bag would keep me warm. This bag is rated at -25 deg F, 3#-13ozs, shouldn't have to worry about the cold.

[Lyle]

Splashup is one reason.

Lower your tarp.

[Tinker]

Splashup is one reason.

Put a hammock under the tarp.

[njordan2]

Synthetic insulation is hands down the best insulator for a backpacking sleeping bag. When down gets wet, it has the insulating properties of wet toilet paper. I have slept in a synthetic sleeping bag that was soaked enough that it had to be wrung out, and still stayed warm. In fact, sleeping in the thing actually dried it out.

I have also slept in a down bag that was only slightly damp and felt like a cold cotton towel was wrapped around me. Because the down bag was not a fast drier, I carried around all the absorbed water for a couple of days until the thing dried out. So in the end, a down bag of the same rating as a synthetic bag can actually weigh more if it does not dry out as fast as synthetic.

Down's inability to function when damp rules it out.

[swjohnsey]

I guess that is why 90+% of backpackers are carrying down bags.

[CrumbSnatcher]

they probably carry down because they are lighter not better :-)
i'm not saying synthetic is better, easier to get down in the smaller packs people are using these days.
how about the down with waterproof shells? rains alot out east, i personally like synthetic

[swjohnsey]

Wet synthetics doesn't insulate any better than wet down. Keep your bag dry and you won't have a problem. Make it part of your routine to dry your bag when you get a chance as any bag will pick up mosture just from sleeping in it. I like down. My bag weighs one pound.

[mikec]

I bought a Sierra Designs 0 degree synthetic at Walesi Yi Center at the 30 mile mark on the AT in 1999. That bag was always warm and toasty. I used to throw wet clothes in the bag at night, sleep with them and, in the morning, they were dry. The bag wicked the moisture to the outer shell. Not sure that one could do that with a down bag.

[Papa D]

Synthetic insulation is hands down the best insulator for a backpacking sleeping bag. When down gets wet, it has the insulating properties of wet toilet paper. I have slept in a synthetic sleeping bag that was soaked enough that it had to be wrung out, and still stayed warm. In fact, sleeping in the thing actually dried it out.

I have also slept in a down bag that was only slightly damp and felt like a cold cotton towel was wrapped around me. Because the down bag was not a fast drier, I carried around all the absorbed water for a couple of days until the thing dried out. So in the end, a down bag of the same rating as a synthetic bag can actually weigh more if it does not dry out as fast as synthetic.



Down's inability to function when damp rules it out.

This is a true comment that is why you must vigorously protect your down bag from getting wet. Here are some steps that I always take:

1) (While backpacking) I keep my bag in a dry sack (Sea to Summit) along with a vapor barrier liner (and long johns for sleeping-in)
2) I do not take it out of this bag until I am right and ready to sleep - if I want to lounge and there is a chance of wetness - I just slide in the vapor barrier only
3) I am very careful the manner in which I pitch my tent and organize the groundsheet floor paying careful attention to where groundwater could get and
4) I also take care to make very sure that the drip edges of my tent extend beyond the ground sheet
5) If it's wet, I will carefully inspect shelters for leaks and use my groundsheet and I will avoid crowded shelters full of wet people (barring an emergency)
6) I work hard to control foot-box vapor and pay attention to vapor issues

Now, this said, I always recommend a synthetic bag to new backpackers and those with limited experience -- I have a few that I even loan out (mainly to kids). I also carry a really light synthetic bag myself for summer use when pop up rainstorms can be a pain (but I've assumed we're talking 4-season stuff here). The main (obvious problem with synthetics) is that to be at all comfortable below about 40 degrees is that you have to carry an absolutely HUGE sleeping bag -- so this rules out comfortable AT travel in GA/NC/TN between September and April.

I've spent countless nights comfortably in down bags (and probably a few uncomfortable nights) but I've never had my bag get soaking wet beyond use - just like I've never caught myself on fire or drowned in a creek - I agree that it is a possibility but it's pretty unlikely if you are careful.

[Tinker]

I guess that is why 90+% of backpackers are carrying down bags.

And the more miles we hike the dumber we get! Failing to keep a down bag dry is dumb (though a couple of times in near exhaustion and hypothermia I left the bag out in the rain/sleet for a couple of minutes until I remembered to put it under the tarp ). It dried overnight.

I will say that, if you are habitually disorganized you might be better off with a synth. bag. Keep in mind, however, they don't survive as many packing/unpacking cycles as down bags do before they begin to lose loft.

In the summer, when you need less insulation anyway, a synth. bag is easier on the wallet and, since the insulation (mainly) is the biggest weight difference, a 40-50 degree quality synth. bag isn't that much heavier than its down equivalent.

The lower the rating (if accurate), the more the difference in weight. When I worked at REI back in the 1980s, the biggest selling bag for prospective thruhikers was the North Face Cat's Meow (20 degree). I never heard of anyone freezing to death while using one (but back in the latter part of the 20th century, most NOBOs started off in April, and a super-warm bag wasn't crucial).

Lots of variables, HYOH, etc, etc.

I'm partial to down bags because of how they drape around every small nook and cranny of your body. Synth. bags tend to feel stiff (boardy, if I can make up a word) in comparison.

[Ronnwell]

Use heavy wool blankets and lots of them. Hey, it worked for the cowboys, didn't it?

Down. It will be as warm when you finish as when you started (unless you use a compression sack and crush the plumules of down to death).

Synthetic. It will lose loft slowly as you pack and unpack it. The fibers are given a crimp in a heated environment to make them spring back when compressed. Think of it as a "perm". When repeatedly stuffed, this "perm" relaxes, and, just as with hair, straight synthetic insulation fibers take up less space than curly ones. Less dead air space in the bag means less trapped air (also called loft) which results in a colder bag. The weight will not decrease, unfortunately.
Leave the bag in a hot trunk in its stuffsack (or worse, a compression sack), and the fibers will get soft and lose their crimp prematurely.
Dry your wet synthetic bag in a hot dryer and you could ruin it in half an hour (I did that once, myself).

My recommendation? Get a good down bag and keep it dry. It will last for years.
OR: Get a synthetic bag, saving money,carry more weight and bulk, necessitating a bigger pack, worry less about water, and plan on replacing your bag after your hike or, possibly, once it gets cold again, before your hike is over.
OH- Once you try a down bag and feel how it snuggles around you, keeping every nook and cranny of your body warm, any synthetic bag will feel like a bag with house insulation in it.

Good answer. Everyone's unique requirements requires careful consideration, but for MOST down is the better choice. To echo the thoughts of most here, down bags are lighter, more compressible and last longer which makes a down bag more effective and a better long-term value. I just laugh at the people in this thread saying that synthetic is "hands down" is the BEST choice.

Keeping your bag dry isn't a big deal under MOST situations and the scare tactics are a bit ridiculous. For those that seem to consistently get their bag wet, you may need to brush up on some outdoor skills and strategies. And obviously, if you get your bag wet whether its down or synthetic, its not going to keep you as warm. Of course, there are environments that are notoriously damp for days on end and a synthetic bag may be a better choice.

All of that said, down bags are a superior choice for the vast majority of backpackers that are looking to do multi-day trips and who have even moderate sensitivity to weight. This is especially true for a thru-hiker (getting back to the OP's question). Investing an extra $100 to $200 is worth shedding the extra pound or two as that weight adds up over the course of a 100+ day thru hike. Additionally, the extra room in your pack might enable you to have a smaller pack, saving even more weight.

[Tenderheart]

Was just wondering if anyone had experience with the Kelty Cosmic 20 Deg down bag. Campmor has it for 90 bucks and weight is only 2.5 pounds. Hard to beat for the price.

[nufsaid]

Wet synthetics doesn't insulate any better than wet down.

......

Untrue.

[Old Boots]

You should be able to keep down bag dry from external moisture sources. The moisture you cannot prevent is condensation which is internal.

[leaftye]

You have to try pretty hard to soak down. I've had some wet nights, and I lost some warmth, but the down still added a lot of warmth. On many of those nights I would have been warmer if I used a vapor barrier. My problem is usually that I sweat so much that I soak my bag from the inside out. That's not a problem with a vapor barrier. A vapor barrier can even make a bag warmer at the end of the night than at the beginning because it can drive out moisture that was already in the insulation.