Ursack Minor Compromised – Repost

Because folks should be aware – the post can be found here – https://backpackinglight.com/forums/topic/73884/#post-1958779

From the (2013 FAQ)  Ursack Minor Product Catalog –
“We’ve tested the Ursack Minor with various critters including mice and dogs, and although it came through unscathed, we rely more on the technical specifications to know that it works.”

Midway down the FAQ –
“We now make a rodent resistant bag, the Ursack Minor. It is not effective against bears although we think it is more effective against rodents than the AllWhite. Other rodents have varying degrees of success. Sometimes mice can chew very small holes, but very little of your food is likely to be taken.” [Emphasis added.]

A small hole by itself is no big deal.  But getting inside, nibbling into stuff, and leaving “presents” IS a problem. (The top of the referenced post shows the holes in the “yellow kevlar” bags.)

I do not know if materials have changed since 2013.

Do your homework if you are considering a Ursack Minor as a “critter bag”.

Mice only chew small holes in silnylon and ziplocks too, so that material does not stop them at all.

Rumor has it that cuben fiber (er, dyneema composite fabric) bags are supposed to be rodent resistant. Anybody ever put one to the test?

Why the dead thread repost? Recent argument with someone about it?

For mice in the AT shelters in 2012, I found the Ursack Minor worked well.  I’d normally place the bag next to the wall near my head at night and I often could hear mice trying to chew on it for a while before giving up and moving on to easier pickings from my neighbors.  Never saw any damage.  So for my application I’d say it works fine.

In the Grand Canyon, I’ve found that some of the birds (especially ravens) are more damaging to food bags than the rodents as I’ve seen some of the metal mesh ones ruined.

Leaving them on the ground or in a bear box with holes big enough for mice is asking for trouble.

Both the Major and Minor are advertised as resistant, not proof.

My cuben fiber zpacks food bag definitely has evidence of mouse nibbling around the velcro. MYTH BUSTED!

5-6 years ago I performed some beta tests for a guy that wanted to sell cuben roll-top bags for use as food storage. He specifically wanted to know if his bags were (1) waterproof, (2) odor proof, and (3) critter proof.

I opened a can of Fancy Feast cat food, placed it inside a Ziploc freezer bag that I didn’t seal (hoping this would keep the inside of the cuben somewhat clean), and it all went into a 1.43 oz./yd. cuben roll-top bag. I tied it to a tree in a place where I knew there were lots of nocturnal critters passing through–skunks, raccoons, foxes, and others.

Nothing happened the first night, but all hell broke out in the middle of the second night. It sounded like raccoons with all the squealing. The bag was relocated 50 feet away from where I put it. I was glad that the cord held, or I likely would have lost the cuben bag.

The results were that after all the critter commotion and competition, there were just 3 tiny holes in the bag, each about the diameter of the lead of a pencil. No tears, no breach of the contents, but a lot of slobber marks all over the bag. It was obvious that the outlaw tried to bite through the cuben everywhere.

My observations:

(1) Before that test I filled the cuben bag with water and hung it up overnight. In the morning there was a small amount of water on the ground below it, and I could see weeping of small droplets of water on the outside of the bag. Nope, this bag wasn’t actually completely waterproof.

(2) It was obviously not odor proof, or else the bad guys wouldn’t even have bothered with it.

(3) It certainly was reasonably critter proof, at least for large and small rodents. I expect that it would have worked against foxes, coyotes, dogs and stray cats as well.

I had also done some beta testing for David Brandenberg’s S.O.S. Outsak. The same drill as for the cuben bag, with the exact same results (with the exception that none of the steel mesh was torn). Valerie has shown us a photo of where a Grand Canyon raven pretty much destroyed an Outsak, which surprised even David B.

Since I don’t find myself around ravens much these days, I have come to using the “belt and braces” approach of using a 1.43 oz/yd cuben roll-top bag INSIDE an Outsak. I know that they each will work, so why not use both? I make my own cuben roll-tops, and I take extra steps to make them waterproof. What I especially like about them is that they keep all my food completely dry, even in the most vicious thunderstorm.