Water gets into Bear Vault

[balzaccom]

On our recent trip to Mono Pass and Pioneer Basin, we had something happen that really took us by surprise.  No, it wasn't the hailstorm that clobbered us right at dusk--although we had hoped we would miss that particular adventure.  But it's related to that.

 

The next morning, when we got up and inspected the damage around our campsite from the hailstorm, we were surprised to see about a half an inch of water sloshing around inside our Bearvault. 

Huh?  The bear can was sitting away from our tent, in a small clearing among some trees, and it was upright the entire time---from before the storm hit to the next morning. So how did all that water get into the can? 

All we can imagine is that the small lip on the bear can that sticks out beyond the lid was saturated during the rain and hailstorm, and that the can and its contents were relatively warm from the day's hike.  As the contents cooled, they must have created a bit of a vacuum, and if the lip were saturated with water, maybe the vacuum sucked the water standing on the lip up through the threads and into the can.  And that continued for some time, because the storm lasted a while, and the really cooled down everything--there was still an inch of hail on the ground when we woke up the next morning.

Anybody got a better explanation?

[HikerJen]

What type of bear vault do you have?  Was it the type with the screw on lid, or the recessed opening with the lid that you snap into the opening?  With the latter, I'd suggest storing the vault upside down.  Otherwise, Rangers at National parks recommend lining the bear vault with a small plastic bag.   

[balzaccom]

It's the screw on lid:  BearVault 450 and 500 ( we have both.) 

 

Do you have a link to those recommendations from the rangers?

[toejam]

Weird! Never heard of such a thing. Bet you've been in a lot of thunderstorms without that happening.

[balzaccom]

Yes--buy maybe none were this dramatic, or carried this combination of lots of water/hail and a big change in temperature...

[HikerJen]

Sorry for the late reply - I don't have a link, just practical advice from a couple of Rangers at Yosemite and at Denali.  They advised lining the bear vault with a small plastic bag and twisting it closed before closing the bear vault.  I have a bear vault like yours and have never had any problems like you had - very strange.

[balzaccom]

Sarah at BearVault was kind enough to respond to our recent questions about water getting into the BearVault during a storm.  Here's what she wrote:

"There is a small lip on the BearVault housing which prevents a bear’s claw or tooth from getting under the lid during an attack.  If the BearVault is almost perfectly upright then during a rain this lip can allow a small “moat” of water to form at the top of the housing.  If the storm then passes during the night, the atmospheric pressure gets higher and this forces the water in the “moat” up the threads and into the housing.

To prevent this, just tilt the unit slightly during the night so that the water cannot accumulate in that “moat” if it rains- it’s that simple."