How long is too long to keep a down sleeping bag and jacket in their stuff sacks without harming their insulation ability? I will be taking them on a trip this summer for two months but not sure I will be using them.
from my amateurish research, it appears that quality down can be compressed for years without losing much, if any, of it's resilience. Though it is highly recommended to store in a manner that lets the feathers stay expanded, and dry, as much as possible.
From my own experience, compressing down for weeks at a time had no effect. That said I always shake out my down products as much as possible as soon as I pitch my tent to allow the down time to expand as much as it can before sleep. The longer my quilt/jacket has been compressed, the more I shake it out and time I give it to expand (when I don't have to immediately put on the jacket)
I also shake the feathers around in the baffles to make sure they are evenly distributed and not bunched up.
One lesson learned from others, is I now stuff my down quilt into the bottom of the liner inside my pack, this actually saves space by filling up the bottom corners of the pack, and compresses as much as necessary when my other stuff is loaded on top.
good luck! send pictures!
@Kurt Thanks for reaching out!
@Philreedshikes pretty much nailed it with all his points. The only thing we would add is that it would be beneficial, if possible, to periodically take out your down items and allow them to loft during your trip.
In order to maintain their best performance, manufacturers recommend storing your down equipment in a storage sack that allows the down space to remain lofted. You can find more good information about storing your sleeping bag in this Expert Advice article about How to Store a Sleeping bag.
Hope this helps!
@Kurt You've already received a ton of great info, so I'll only add one thing. I am a big fan of using down wash every couple of years to just bring the loft back to life and add some water repellency. It doesn't cost much and you can use it on jackets, bags, even down pillows or comforters. Just my little pro tip. Here's what I use: Nikwax Down Wash Direct