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To compress or decompress, that is the question...

Hi everyone,

Well I got a really nice quilt and it is without a doubt the most expensive item in my kit.  Therefore, I need to be extra careful with it.  I know that it came with a stuff sack, but I wanted to get it smaller than that so I was going to use a compression stuff sack.  I have heard that you can compress them too much so I was curious as to what you all use.  I store it in the big bag that they sent with it so what I am talking about is while on the trail.  I read though that you can ruin a bag by compressing it too much while on a long hike.  If you guys (and gals) use a compression stuff sack let me know which one you use.  :) 

Edit:  It is a down quilt....

It is fine.... there is a lot of fear-mongering with this stuff. Just make sure it isn't wet when you compress it otherwise you are going to get some unpleasant clumping.

Enjoy your quilt, take reasonable care of it, and use it in a way that is most convenient to you. You are more likely to wear the thing out from actual use before you do serious damage by compression during transport.

As TJ alludes, long-term compression is fine so long as the down is dry...the real culprit when talking about down degradation is cumulative compression/expansion.

Thru-hikers will notice their bags aren't as lofty at the end of a trail, and this is merely the effect of stuffing/unstuffing hundreds of times. There will be permanent loss of loft.

OTOH, you may notice your bag isn't as lofty as you might expect after having been stuffed in a tight stuff sack at the bottom of your closet for a year, but, if you give it a couple days, fluffing it up a couple times a day, it will rebound completely. For those of us with small gear closets, it's really the only choice!


It's general wisdom where I live to let the bag air-out as much as possible in the morning after you get out of it (before I knew anything else on the topic I emulated others I saw doing this). I also agree that the fear of compression damage is a bit oversold in the context of a typical short trip (overnight to a week). I've only seen my bags lose loft either after years of use by nasty old me or at the end of a multiple day trip in bad weather where I couldn't air it out much at all.

I like to type Snakey. I'll do it one more time: Snakey.

Often times the loss of loft is due to dirt and oil accumulation -- with most items of high-quality down that have lost loft, you'd be amazed at what comes back with a simple wash.

I would opt to not compress. I don't like compression storage in general, you turn the item into a hard lump that is too stiff to mold its shape and leaves dead space around it in your pack. I think it will take less "space", by allowing it to fill all the nooks and crevices in the bottom of your pack, if left not only uncompressed but unstuffed. If you use a pack liner then of course it goes inside that.

I agree with JR...I like the way my sleeping bag fills in all the dead-spaces in my pack (my packs carry better with the even tension pushing against the interior walls of my pack).

Thanks guys!  I will always keep it in the big bag when stored.  I did order a sea to summit compression sack, one of those e-vents.  What about liners to keep the oil of your body off the bag?  Since you mentioned that.. JR

I always use a silk liner unless it gets cold enough to push the comfort limit of the bag, in which case I take a thermolite liner.

In the Pack

When backpacking I use one trash-compactor bag (thick trash bag) as a "liner" for my pack, and at least one more to further sort (wet and dirty) items within the primary bag, and to serve as a back-up (multi-use item) for the primary (if items are soaked I do not keep the bag of soaked items in the first bag...only if they are damp). The additional bag weighs near nothing, cost less than $.40, and when not in use is stored out of the way at the bottom of the first bag until I need it.

* When using the 2nd trash-compactor bag I typically put it at the bottom of the first garbage disposal bag so if dirt and moisture do escape gravity will drive them farther down into my pack and not down onto my clean and dry items.

In Use

I do not use a liner for my sleeping-bag, instead I bring designated sleeping/camp clothes (I believe they are more versatile than a bag-liner). The clothes I sleep in keep dirt and oil off my bag for the most part, but I tend to wear a lot more clothing to bed than others so this might not be a good strategy for all (I ALWAYS sleep in long pajama bottoms and at least a short-sleeve shirt).

hey yeah , I actually do almost exactly what Joseph does except my sleep clothes aren't full coverage (no doubt my bag gets dirtier over time). I always intend to at least wash off with a rag before bed but I'm not as disciplined in that regard as I should be; sometimes I'm just too tired or lazy for that chore.

Now that I think about it I guess I should clarify that I don't use actual compression sacks at all but rather just stuff sacks (and only occasionally). I've gained more confidence in the double trash bag method over the last few years.

"Thru-hikers will notice their bags aren't as lofty at the end of a trail, and this is merely the effect of stuffing/unstuffing hundreds of times. There will be permanent loss of loft."

As JR has pointed out dirt and body oil will cause the clamping , not the repeated compression/decompression.

A good wash and dry will restore the loft.

Thanks for clarifying that, Franco; keeping your bag clean is the best way to prevent loss of loft from body oil accumulation. Structural damage to the down clusters resultant from stuffing/unstuffing over many years can only be countered by adding more down.

I have been using down and synthetic bags for most of my life. Being brought up in the middle of the Sonora Desert, our "bedroll" mainly consisted on a canvas wrap around a rolled-up blanket.

My first real sleeping bag came when I was headed to the National Boy Scout Jamboree in 1953 - a rectangular full zip you could spread out as a blanket, filled with duck feathers. I just rolled it up and secured the "shade" (think of a mini Whelan lean-to tent covering your head) around it. You couldn't get much compression.

My first mummy sleeping bag (about 1960) was a -40°F/C Eddie Bauer Karakoram. That came with a stuff sack, but not a compression sack in the current sense. Due to living in a college dorm in a shared room, I left the bag stuffed and in a closet when not in use. I still have that bag. But now, due to storing it stuffed for weeks on end, and having once gotten it dry-cleaned (talk about a way to destroy the loft!!), it is now maybe a -20° bag. I attribute the major loss primarily to the dry-cleaning. Although that was a recommended thing to do at the time, DO NOT EVER UNDER ANY CIRCUMSTANCES DRY CLEAN A SLEEPING BAG, down or synthetic. Not only does it destroy the loft (due to removing all the natural oils of the feathers), but the fumes that remain in the bag for months of airing out are poisonous.

Here are some hints, mostly learned the hard way, to prolong the life of your very expensive down sleeping bag (and also your inexpensive synthetic bag:

1. Minimize your bag's exposure to dirt (at least use a ground sheet under it) and body oils, as well as spilling food out of the cookpot while in the tent.

2. Your body loses about a liter of water overnight through sweat (even if you are sleeping cold). This condenses in the fill (down and synthetic). As soon as you get out of the bag in the morning, roll the bag up tightly, foot to head, to squeeze out the water vapor and condensation. Fluff it up and roll it up again. Repeat 2 or 3 times. Unless you are in a hurry to move campsites (hiking the JMT in under 10 days), let it air out a bit.

3. When you get to your campsite and set up your tent/tarp/hammock, one of the first orders of business is to get the bag out of the sack (compression type especially, but any stuff sack), fluff it up and let it "breathe" while you do the rest of your setup and cooking. DO NOT JUST LAY THAT $500 (or more) bag directly on the ground.

4. Except in dire emergencies, do NOT get into your bag while wet, wearing wet clothes, or covered with snow. Aside from the fact that the moisture will reduce the insulation value, it is always hard to dry out a bag on the trip, and moisture in the dill (down or synthetic) allow mold to grow.

5. If possible, every hundred nights of sleeping or so, wash the bag FOLLOWING THE MANUFACTURERS INSTRUCTIONS. Generally this means using a commercial-grade front-loading washing machine (NO Center Rotors!!!) using one of the top-quality down-washing products (even for synthetic fills), then drying in a commercial-grade, front-loading dryer on warm setting (NOT HOT!). If you feel compelled to use the tennis ball or tennis shoe trick to break up the inevitable clumps, make sure the balls or shoes are thoroughly clean. I would advise avoiding the shoes - new tennis balls work pretty well. Warning - since you probably do not have large commercial-grade machines at home, be prepared with a huge supply of quarters to feed into the machine.

6. DO NOT store the bag wet or in a damp environment. EVER!!!

7. DO NOT store the bag compressed. Sometimes when traveling (such as flying to Alaska to do Denali or the Antactica to pull a sled full of 300 pounds of food and gear), you might feel compelled to compress everythng - not only your sleeping bag, but that nice down parka and pants, so that everything fits. But do not pull the compression straps while having your overweight cousin sit on the sleeping bag to compress it even more.

8. If you are driving a couple thousand miles across the continent to do that backpacking trip or climbing expedition, leave the sleeping bag in that very breathable large storage bag (or get a large cotton "dirty clothes bag) - this avoids leaving the sleeping bag tightly compressed for the week it took you to drive across the continent or the month from New England to Ushaia or Punta Arenas.

9. Yeah, wearing PJs helps. But on a serious backpack or climbing expedition, who does that? For a weekend backpack, that's ok. But how many extra sets of long johns are you going to take on the AT, PCT, or even the JMT? Those PJs and long johns are going to get soaked with body oils and sweat after a couple weeks of campsites without a shower. 

I apologize snakey...I assumed you were asking how to keep your bag clean if you take a lot of shorter duration trips instead of a single long duration trip...since most of us are more or less directly or indirectly moored to the paid economy it seemed like a safe bet.

In the case of non-expedition like trips it is quit common for folks to bring designated sleeping clothes (I call them pajamas only because I was raised deeply conservative and I sleep in them...but these items are simply additional insulation chosen with an eye to comfortable sleep).

Particularly in wetter areas the practice of additional sleeping clothes is considered sound practice...even Andrew Skurka (who is the opposite of a weekend person) agrees on this:

I would also advocate cleaning your clothes before they get gross! I mean...a large reason for bringing and using sleeping clothes is that they are easier to clean than a sleeping bag. Most of my trips are over before my sleeping clothes really need to be cleaned...but in warm and dry weather I clean my sleeping clothes as often as want and weather compel or allow.

If you use a sleeping bag a lot, say more than 50 nights a year you are going to get some dirt on the cover and body oils in the down over time no matter what you wear or line it with. It will impact the ability of the down to rebound from compression. Prolonged compression during storage will also affect the loft of the bag.

These problems are compounded with the use of man-made fibers in sleeping bags, but fortunately they are much easier to wash.


I will use those wicking underwear to bed as a way to prevent the bag from getting dirty.  Thanks guys! 

January 28, 2021
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