Dry Sack as a cache container

[+Jeep4two]

I just hid my first cache and I'm already looking for ideas for containers for the next. I have a 2nd lock & lock painted and ready but I'm looking for something larger, durable and easy to get my hands on.

 

Cabela's and other companies carry Dry Sacks. They are designed to keep the contents dry (bone dry according to some testimonials on Cabela's). They are made of special pvc coated nylon.

 

They are a little on the expensive side ($15-$30 based on size) but since they are already camoed with a very nice woodland/hunting style camo print they seemed to be a good possibility.

 

Has anyone here tried one of these, or for that matter found one? What has your experience been?

 

Here's a link of the one at Cabela's:

 

Link: http://www.cabelas.com/link-12/product/0040814517435a.shtml

[+Casting Crowns]

I think you place too much trust in the caching community....it would probably be taken within a week.

[Clan Riffster]

I can tell you they are not 100% waterproof when used in a kayak. Not sure how they'd do shoved under a bush at Wally World.

[+Shelle518]

We've had one out in an ice chest for several months. The contents gets damp after a while when there has been a lot of rain. Not really the best thing to use. We will be replacing it soon.

[+WRASTRO]

A dry sack is not designed to keep the contents absolutely dry for long periods of time when exposed to large and persistent quantities of water. Probably not a very good container choice. You can toss a 35mm canister into the water and pull it out soon. The contents will likely be dry. Time and exposure will take their toll.

[+Jeep4two]

Thanks for the replies. I suspected that chronic exposure to the elements might be a problem for these.

 

I'm hoping my lock & lock holds up. If so I'll be looking at a larger version. They are so easy to camo paint with Fusion Camo Ultra Flat paints.

 

In the end - I'd have to say that there could never be the same satisfaction from opening a bag that you get from that clanky ammo can, or snap of a lock & lock...

 

Thanks again -

[+paleolith]

In addition to the answers already given: even a tiny puncture would allow water to get through the bag. Also you would need to know the composition of the fabric and waterproofing to know whether they would hold up in sunlight.

 

Lock-n-locks have a good reputation, but the term is usually used here generically rather than as a brand name. Most are fairly heavy polypropylene (code 5, PP), which references say holds up to sunlight. I see somewhat varied results in practice. Heavy PP does seem to hold up, but thin PP does not. Gladware claims to be PP but totally falls apart after a couple of years in the sun. Lock-n-lock type containers are thin at the hinges, and the tabs often fall off, leaving the container 99% intact but useless. Recently I found a lock-n-lock cache with one tab left. Found two of the tabs on the ground. It was only about three years old, with about 60 finds.

 

Decon containers are popular for various reasons, and one of those reasons is that none of us has ever seen one deteriorate from exposure to sunlight. They aren't marked, but may well be PP.

 

Anything made of polyethylene (HDPE, LDPE) will die a quick death in sunlight.

 

PET, PETE, and PVC hold up for a long time. Polycarbonate and ABS will outlive your grandchildren.

 

However, most of the durable plastics are too stiff to provide a good seal, so a softer plastic has to be used to get a good seal. Decons don't, due to the way the cap is built and the fact that the material has some flexbility. But most PP, and all PET, PVC, polycarbonate and ABS, must have some other material for the seal, or they won't be watertight. The cap on a PET soda bottle is lined with something else. Even threaded PVC pipe will let in moisture if you don't add a sealing compound to the threads. Whatever the seal is made of is likely to be the weak point, and few containers are labeled as to the composition of the seal. But at least in most cases, the seal is protected from direct sun exposure by the container itself.

 

Lock-n-locks share two important attributes with ammo cans: the locking mechanism is separate from the seal (rather than asking one part of the container to act as both, as in Tupperware-type containers), and as a result the lid protects the seal. I think these are important to the success of both.

 

I recently saw a container which looked like ABS, with side-locking wire clips and a flexible seal under the lid. I think it was made of ABS -- sort of an ABS lock-n-lock with wire tabs. Unfortunately I neglected to examine it for manufacturer info.

 

Edward