Valved dry bag

Should work. I've got a couple, I'll have to try it in my Jam2 sometime.

Excellent. I'd love to here the results. I imagine the most difficult part would be having a dry bag that matches the specifications of your pack well.

I've heard this works too..

1 item 4 uses!

I've actually used this technique (more for river crossings though). It can work, but on a frameless pack I found it "rounded" my pack agressively so things fit less than ideally and made it much harder to pack for comfortable support.

>It can work, but on a frameless pack I found it "rounded" my pack agressively so things fit less than ideally and made it much harder to pack for comfortable support.

Yep. That's what I've found too.

If the valved drybag is also a sunshower, you can take a shower on your zero days.

I have a pocket shower and can stow my quilt inside, blow it up and provide some protection from compression. It's not big enough to fill up my pack, however.

This is a great idea. I have heard of people doing something similar, so I can't wait to hear how it works out for everyone.

Have tried it using Hypalon dry bags. It works as long as the bag holds air, but any failure to seal will let the bag sag. As someone noted, the air pressure makes the bag cylindrical, putting the center of mass further from your back – an inefficient carrying situation. OK for portages of reasonable distance but not something I would like to haul all day.

Something else to consider. In backpacking, you normally ascend and descend constantly. On some trails, altitude can change 3,000 feet or more during the day. As you ascend, pressure in the bag increases relative to the barometric pressure outside, and the bag is more likely to bleed air. As you descend, whether the bag leaks or not, the relative air pressure in the bag will decrease, causing it to sag. The only way to keep pressure up would be to pump it or to open and re-close the bag to normalize the pressure.

i have a pretty nice watershed rf welded drybag that i will many times carry on backpacking trips. it is one with a ziplock bag type closure. i use it like a mini refrigerator for items that need to stay cold. close up the bag, tie it to a big rock and sink it in the lake right off shore. i usually use a small piece of cord to tie it to a root on the bank just so it doesn;t get any bright ideas about floating away. keeps your food cold, and since it is submerged there is no smell so it is for the most part animal proof. keeps butter, cheese, veggies, fruit nice and cold for a couple of days.