why is the stuff in my pack wet?

[JC13]

I have used it for both when I used a bladder, the water in it will cool overnight and cause condensation as the day heats up.

[Just Bill]

I had it packed, testing out the weight, and sitting on the back porch for the last couple of days. There's a 2.5l Osprey bladder in there, and this is in sunny, hot, dry Sacramento.
Well, not so hot right now; the mornings are cool
But I opened it up this morning, and everything is a little damp. Not soaking wet, tho. And the bladder is still showing 2.5l, tho the outside of it is also slightly damp. And some of the stuff that's damp was above the bladder.

I'm hoping this has nothing to do with the bladder and is because of natural condensation....or something like that...

Not knowing the weather in your area that'd be my guess.
Generally a 20 plus degree swing is enough to cool the water enough to then develop condensation in the morning. Sat a few days, and was on the porch in the shade so probably didn't get roasting hot in the sun during the day.
In theory- a trash compactor bag would have prevented the moisture from getting in- but your gear filled trash compactor bag might have just acted like a big bladder too filled with cold air and cold water and the pack itself would be damp.

Lotta "leaking" bladders on the hot humid AT are simply cold (40-50*) mountain spring water getting carried about on a 80-90* day with bazzilion % humidity.
"Ain't no such thing as a glass o' sweet tea that don't sweat in the summer, lol."

Course operator error is high on the list too- so double check things but if I remember right the Osprey's were pretty overbuilt bladders compared to a typical bladder so I doubt you messed up. Usually the only thing that I tend to do is accidentally compress the bite valve when I set the pack against something. If you have all the compression straps cranked down and a full bladder-any little pressure on the bite valve will cause it to leak.


Oh and if your shelter suddenly "fails" when you camp 5' from a mountain stream in Virginia in a katabatic valley- I'd be happy to buy it and your leaking water bladder for $20.

[Just Bill]

I'm thinking now that maybe y'all use these plastic bags, mainly because you're hiking the AT where you have to be concerned with wet weather, right? You aren't using them because you expect your bladders to be causing moisture problems - or are you? I would LOVE to get some of your rain, but the weather is bone-dry out here...

if you are using a trash compactor bag- just slide your bladder outside of it between your backpanel and the bag. No separate bag needed.

inevitably- be it condensation or an error- we all have a bladder leak. That said- we all walk in the rain every once in awhile too so getting wet once in a blue moon bit of an overblown issue I think.

If you lived and hiked on the water rich AT all the time... you might be able to dismiss the bladder as not worth the trouble. But for the rest of us who often have to carry 3-4 liters in other areas of the country... I'd learn to use a bladder. The safest to use is just a bladder with a cap. Give it a squeeze before you pack it up. After that, every part and piece beyond is a chance to fail but it's not that often that something leaks.

[Slo-go'en]

The 2.5L of water is causing the condensation to form due to it's thermal mass. This would not normally be a problem as you'd not have much of anything in the pack overnight.

[jefals]

The 2.5L of water is causing the condensation to form due to it's thermal mass. This would not normally be a problem as you'd not have much of anything in the pack overnight.

Great! I'm not sure what you mean by thermal mass -- but -- I was hoping it was something like that!
Thanks much!

[saltysack]

I've been using the same compactor bag for several years...put the bag in the pack first then stuff all dry cloths and quilt inside.


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[mikec]

I always put a piece of Duct tape over the bite valve of my water bladder between the time I pack and the time that I hit the trail. And I also place all non-water proof items in a plastic freezer bag in my pack. At least these 2 actions make it less likely to have a pack full of wet stuff.

[Alligator]

Great! I'm not sure what you mean by thermal mass -- but -- I was hoping it was something like that!
Thanks much!

If you are going to keep the bladder full overnight, you could also take it out of the pack.

[Wise Old Owl]

Swell I read most of the posts - I am with Odd Man Out... you misjudged the condensation... forget the trash bag around the bladder - won't work... I use a good trash bag for the entire back pack - not the bladder now. For the bladder I use a well made Reflectix with foil tape... Why? It reflects the heat from by back to not heat the water. I use a sill dry bag for the down sleep system and everything else is basically waterproof. No condensation will happen with this system unless its ex stream temps.

Hope this helps... if not request pics.

[Leo L.]

Not sure if this applies to the specific situation described, but I found that having sweaty cloths in the pack will attract humidity and cause condensation over night.
In real hiking life you will hardly ever put your sweaty clothes inside the pack overnight, but rather try to air them out.

[neghsmoke]

I can only assume it's exactly like a solar still. Anything that was holding any moisture at all, sat in the sun and condensate traveled upwards to settle on gear near the top of the pack.

[Bronk]

Best get used to everything in your pack being a little damp and smelling like mildew.