Down in Compression Sacks?

[JCINMA]

I've heard people say that it is bad to compress down too much, and compression sacks should not be used. Why not?

[Trooper]

It is inherently compressible, so you can compress it and still have it return to its full loft. However, if you compress it too much, it damages the fibers and it won't loft as much as it could. Much like leaving a spring compressed for too long can give it a memory, and reduce the spring's potential energy. Synthetic fibers are generally more resilient, but again, don't overdo it.

Basically, too much of a good thing is bad.

[beep]

I've heard people say that it is bad to compress down too much, and compression sacks should not be used. Why not?

In general terms, compression sacks can really compress the down...as they are designed to do. Repeated crushing ("compression") of the down will reduce the ability of down to return to its original uncompressed volume. Proper washing can restore some of this fluffing up ability, but avoiding "maximum compression" is a strategy to minimize damage to the down bits.

Fortunately, down IS somewhat compressible. Some hikers advocate putting the down articles into the pack WITHOUT a stuff sack and then piling in the rest of the gear on top, compressing the down only as much as needed to close the pack.

I use stuff sacks, but size them so that my down items are not super compressed. In that state, if they need a bit more compression because of pack load, they will do that, but otherwise they are compressed only as much as they "need" to be compressed for the volume of gear I'm carrying.

FWIW, down can be compressed and fluffed up MANY more times than any synthetic with relatively little loss of lofting ability. I have a 30+ year old Holubar down sleeping bag that is still quite toasty (albeit heavy in relative terms).

[Jsaults]

It is one thing to compress down items for PACKING (such as days on the trail) and another thing altogether to compress them for STORAGE.

Long-term storage in a compressed state is hard on the down pods, and will lead to premature breakage of individual barbules from the pod. I have a Sierra Designs 200 bag from the late 70s that has been stuffed & compressed for trips, but stored in an oversized sack and it still lofts admirably.

Jim