ZPacks Cuben Dry Sacs – Air Leakage

Definitely. I bought one about a year ago and it's pretty much worthless as a dry bag. At the time, their dry bags were completely sewn which was a bit of a shock.I don't know if they've switched to at least bonding the sides and bottom now. Lawson's were really great, hate that he quit making those. I just make my own now.

Ryan

Can you remove the velcro?

Humm, while they do use the word "dry bag" (perhaps they should use something else) I would point out that it is (1) fairly clear that these are for pack liners not traditional dry bags, and (2) as such many people would definitely NOT want them to be perfectly air tight, as in my experience I would rather pack cloud-style with a liner that can be compressed a bit. I always found that part awkward when using a trash compactor bags, though I'm sure many here would legitimately tell me to get over it. LOL

Still I'm very happy with the zpacks "dry bag", for what it is, *including* the fact that it is not air tight which I view as a feature, not a flaw.

I bet there is some kind of simple hack to fix this for you, though for the price I guess we should possibly expect magic leprechauns to make a house call and fix it for you.

I have one with taped seams. I filled it up with some water and found it leaked at the corners and seam intersections.

I discovered this because I had my sleeping bag in one, and after a long rain, opened up my pack to a damp bag. I no longer use these as dry sacs.

Well drat! That is way more serious than air leakage, IMHO.

You know it is probably "easy" to fix yourself (though annoying and time consuming). Before you try I'm pretty sure you could also send it back for replacement under those conditions if it is clearly not due to abuse or user error. You might try *that* since they have great customer service in my experience. I haven't seen that complaint about that particular product here before, and we have a lot of zpacks customers on here. But I could easily have missed some. The folks on here are pretty unforgiving if they discover this kind of thing consistently, and then pretty much everyone knows.

I haven't had this problem. I just have one large pack liner so I can roll it down a bit and don't rely on the velcro to keep it air/watertight.

I never thought of sending it back – I had been using it for a few months, but that was the 1st time it saw any serious amount of water. I tried seam-sealing the seams, but it mostly flaked off after a few weeks.

–

From the Zpacks webs site: (note the 1 year warranty)
Cuben Fiber Roll Top Dry Bags

Description:

These stuff sacks are sewn "envelope" style with a taped seam down the side and across the bottom. The top of the bags roll down and clip together to keep out water. The roll top can also be used to compress the contents.

Constructed from black 1.0 oz/sqyd Cuben Fiber material. By comparison our regular stuff sacks are made from thinner .51 oz/sqyd material.

Fully taped / waterproof seams.

The top of the bags seal with stiff velcro to make closing and rolling the top easy!

Also check out our new Zip Pouches for waterproof protection for your smaller items like your wallet, camera, phone, passport, glasses, etc.

1 year warranty against defects in materials or workmanship on all ZPacks gear.

So, you folks have me geeking out bringing up this topic. I hike in the PNW, and I've always packed everything in stuff sacks, being more than a little concerned about how dry my stuff stays. I've never had a wet kit, so I felt that this method, combined with a pack cover, worked pretty well. However, I remember Mary D mentioning long ago that she tests her stuff sacks every spring before setting out on the trails backpacking, and I've never done that–thought it sounded like a good idea.

So, I have both Zpacks Cuben sacks, and MLD Cuben sacks. I also have a few Sea to Summit bags left over, some silnylon, some heavier–possibly PU?

The first test I did, I filled the sacks with water, rolled down the tops 4 times, then put a little pressure on them. I did 1 Zpacks, 1 MLD, and 1 S2S silnylon. All 3 of them had a little water drip from the corners, and, all 3 had water squish through the roll-top closure and leak.

Huh, I thought, well, really, that's not a good real world test–when would the sacks ever need to hold water pressure? So, I took 3 more sacks–Zpacks, MLD, and a S2S PU bag. I put some dry paper towels in them, rolled the tops down 4 times, did not evacuate all the air from them, clicked the clips, and submerged them in a tub full of water (note to self, use warm water next time!). Each sack allowed air to escape the seal–all of them. they all deflated a little. However, when I opened the sack, the paper towels inside were dry, except for the MLD bag–but I held that one under the water the longest, and evacuated ALL the air through the roll top closure.

On the S2S PU bag, there is a tag, which states "This Sea to Summit Dry Sack is made from high performance water proof fabric, heat sealed tape seams with a roll down *watertight* closure. Use to keep contents dry in any wet situation where *the bag is not submerged.*"

So, neither test is really a good test of the bag's performance, and it is not realistic to expect air not to escape. All you really want, is that the bag sheds rain, does not allow seepage through the material, and preferably not to fall into creeks or go scuba diving with your backpack.

In writing with Joe Valesko on seam sealing my new Arc Blast ( I bought one of the older ones that didn't come with taped seams), I asked him if I could skip the stuff sacks now, as the backpack will be water-tight? He said that he didn't trust just one method to keep equipment dry, and would back up the seam sealing on the backpack with either a pack cover, or stuff sacks or pack liner, but not both a cover and roll-top bags.

I've always been a little uncomfortable with the notion of a roll-top backpack closure, and now I feel justified–would it really be water-tight in all day rain, or could pooling occur on top, and allow water to seep inside? If the pack-cover protects the roll-top closure, that might be enough. If the contents are protected inside by a second roll-top closure, it would be harder to seep through both–but, the bag on the bottom of the backpack, where leaking water might collect, had better not have the closure on the bottom, and probably shouldn't be placed inside the backpack sideways either.

I'm not sure what this means in terms of how I shall carry my gear in the future. I'm going to have to think it over–I like stuff sacks for the organization feature, have never liked carrying my gear loose inside a pack liner.

Predictably, after asking Joe about this by email yesterday, I received a sameday reply offering his help to understand the issue and address my concerns. Just a great company. I will update the group on the outcome.

Derrick

Derrick, yes do let us know what is going on, and how it was resolved/repaired.

Joe is the best. I expect he will fix the problem.

I think of all my cuben "drysacks" as rain and splash resistant only.

Which is normally enough.