Cuben and silnylon

[M B]

I recall a thread a while back that showed that cuben had some poor hydrostatic head testing results. At the time I thought it was mildly interesting. Now when considering a cuben shelter, it is more important to me.

What are peoples real-world experience with cuben shelter after prolonged use? Does any misting occur? Do leaks develop eventually at creased areas, etc? Im sure a dot of silicone would repair any imperfections that did develop, but the poor hydrostatic head test still has me wondering about the sanity of investing 500-600 in a shelter of cuben.

Also along those lines, saw a lot of discussion in past about the properties of silnylon used by lightheart, shires, and six moons. I do not recall any discussion of MLDs material. I know MLD has a great reputation, but what hydrostatic head rating is used by them in their shelters, does any misting occur, etc.? I dont recall ever seeing any info on this on their website.

[a b]

I used an MLD Patrol shelter made of .75oz/sq yrd weight green Cuben fiber for 70 nights out of 95 on my AT thru hike this year.
I stuffed it into it's stuff sack without rolling it up or taking any specail care of it.
Water never penetrated my MLD Patrol shelter even during intense downpours and heavy winds.
In fact i experienced heavier rain and wind on the AT this year than i did on the PCT or CDT.
The Cuben fiber of my $300 dollar shelter never absorbed water, leaked, or misted.
In fact even the creases from being stuffed dis-appear after the shelter is set up over night.
Additionally my Cuben fiber patrol never stretched or sagged regardless of how wet the weather was. I never needed to re-tension lines and the shelter NEVER flapped in the wind even a little bit.
I don't know what the hydrostatic head rating of cuben fiber is. I just know my MLD Patrol made of cuben Fiber never leaked a drop over 2,180 miles.

[Richard Nisley]

Matt,

MLD specs for the Cuben version of the Patrol Shelter state, "5.8oz .55 Cuben fiber version. Contact MLD first. Custom- Non returnable."

Was your Patrol Shelter a 1.26 oz/yd2 or a .55 oz/yd2 version?

[a b]

Richard, I got the .75 oz/sq yrd version. The spec says it is 6.8 ounces total for the shelter less guy lines and mine weighs 7 ounces on my scale.
The 1.26 oz/sq yrd is for my TrailLite designs cloud cape. Sorry, that was my mistake.
Incidentally my favorite use for my Cloud cape was as a ground sheet for getting into and out of my patrol shelter in the mud. I am getting ready to publish a review of the Cuben Cloud Cape i used on the AT. I had good results but not in the way I originally thought. Anyhow.. more to come.
That 1.26 oz cuben never leaked either, even when I sat on it directly in mud or pushed a foot or elbow into it.
The sil-nylon floor of my bear paw wilderness designs minimalist bivy would admit some moisture under the same circumstances.
Also my Gossamer gear One tent with the spinnaker floor would leak if i pushed an elbow into it.
The Tyvek ground sheet i used for the CDT only began to leak after 500 miles of use.
The polycro ground sheet i used on the PCT never leaked but eventually tore at mile 1,200 on the PCT.
Anyhow i am interested in the hydrostatic head numbers for Cuben Fiber. i could not find any real figures anywhere. Are there any articles i am missing in BPL?

[M B]

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=44516

[a b]

Great link Thanks! (I find it a little odd that we can't simply click on links here on BPL.. anyways)
Hey, so when are we going to see the results of those tests alluded to in that thread from last April?
I understand you are not being paid to do them Richard and I am sure all of us greatly appreciate the science you bring to bare on these subjects. Thankyou for your work Richard!
I am amazed that the first sample of Cuben fiber tested so low and yet I had absolutely not even one drop of water hit me throughout multiple wind and heavy rain events on the AT this year. This is in contrast to the very definite misting i had under the spinnaker shelter i used on the CDT. Even after wiping the inside of the spinnaker with a shamwow i would get misted from the windward side every time a heavy gust of wind came.
On the AT I had even heavier winds and a lot more rain.. just check the weather history from Georgia in mid March to Maine in late June. It was a record setting spring for precipitation.
I would send you a sample but there is no force on earth that could seperate me from my beloved MLD Cuben Patrol shelter!
Still, it would be interesting to see multiple samples tested. A sample size of one is obviously not statistically significant.
I am willing to bet Ron Bell at MLD would provide you with some samples to test.

[Richard Nisley]

Matt,

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=45026

Summary: Cubic Tech doesn't quality control HH. In addition, their non-disclosure agreement prevents anyone who buys material from them and tests it from publishing the HH. Some .08 Mylar thickness submissions were very porous even before they were aged. All of the .18 Mylar thickness submissions tested well.

[Adrian B]

I've used a cuben Patrol from MLD a huge amount since late 2008, mostly in New Zealand in the South Island. Probably several hundred nights all up, I really should have kept a log. Lots of hard and continuous rain, no issues, no leaks aside from when my initial seam sealing sprung a couple, which was fixed with another round of sealing. Folding doesn't seem to cause any apprecible wear that I can see so far. I do have some (5?) very small pinprick holes from either camping too close to fires, or conceivebly rolling the tarp up with sticks/twigs/stones caught up while all my weight is on it (maybe you can tell I haven't babied this thing). Practically they don't affect the waterproofness though, otherwise I might bother to repair them – I only began noticing them when the moon was above me at the right angle one night. So far I can't see why it won't just keep going and going, the guylines are wearing out long before the tarp itself is.

With the Patrol I also bought a cuben bottomed MLD bivy, which was a custom order. I wasn't sure how it would last, but I've been impressed – it's looking a bit tired in the head area but it's still serviceable. I use it on top of a foam pad (on the outside) which helps protect it and means leaks are less of a problem on very soggy ground. Most of the wear probably comes from only using a fairly stingy torso length pad which leaves the head area directly on the ground, which is often where my elbows and knees end up putting a lot of weight and wear on it. Using a full length pad would make it last longer. Having never used a silnylon bivy I don't know how tired one would look after the equivalent use (probably also pretty tired), but I'll happily buy another cuben bottomed bivy when this one wears out.

I've also used a cuben stuff sack from Granite Gear since they first came out. I found the sea to summit silnylon ones leaked (during all day rain, and during some swimming with a pack on), so switched to polythene bags. But I didn't like continually buying and throwing these out, and the lack of durability always made me nervous, so was glad to switch to the Granite Gear cuben bags. Never had a leak, and this includes during packrafting.

Besides the weight, I love the small packing volume and the fact the material absorbs no water, unlike silnylon which can wet out.

It's interesting reading about some of the lab tests, and I hope they go on, but I wouldn't hesitate in buying any cuben gear because of them.

[Adrian B]

I forget misting, which still seems to be a murky topic.

I'm not sure it's anything more than hard rain dislodging significant condensation on the underside of the fabric.

Regardless of cause, I haven't noticed any misting in my cuben Patrol, but that might be because I'm always protected to a certain extent by the bivy bag, or I might have assigned it to wind blown spray/splashing from the side. I did have a very bad night of misting in hard rain in my silnylon Lunar Solo E, but I paticularly noticed this because I had no bivy bag.

(edit: it was a Lunar Solo, not a Double Rainbow. It got me through plenty of other rain ok though, I didn't nurse hard feelings.)

[Richard Hanson]

Matt and Adrian,

Right now I am using an MLD tarp and bivy but I have been thinking hard about ordering a Cuben patrol shelter. I am going to need a "tent" for Philmont, and I think if I pair a patrol shelter and a serenity shelter, that will pass as a tent.

I am thinking hard about ordering the patrol shelter about a foot longer than normal. I want to be able to use the extra space as a vestibule for gear storage and cooking, but I have no idea if this will work. It would be a kindness, considering that you both have extensive experiences with the patrol shelter, if you would offer your opinions.

Thanks,
Richard

[a b]

I used a Bear Paw Wilderness Designs minimal Bivy inside my MLD Patrol Shelter.
Each night I would set up my Patrol, get inside and unfurl the mesh bivy and attach it to the cieling of the Patrol.
I found I was able to keep all my gear inside the bivy with me at the head end and still be well under the beak of the patrol.
I also used a trekking umbrella stuffed under the beak sometimes in heavy weather to allow me to have a bit of extra space.
The Patrol shelter is a LOT bigger than it looks from the pictures.
Typically my head was a foot behind the apex of the beak and my feet were well clear of touching the end of the shelter.
I am 5'7" tall but like I sadi, all my gear was inside with me too.
The great strength of the Patrol design is the variable geometry of it's set up. You can set it high or low and still get a taut pitch on all panels and the ridgeline. I even found out it was easy to adjust the pitch in the middle of the night is conditions changed from underneath the tarp.
What does geometry have to do with length? Well the beak of the patrol swings in or out depending on the width the tarp is set up at.
I believe Ron has dimensions for the Patrol on his site but i can set mine up and measure the dimensions from low pitch to high pitch for you.
Gotto go to work now but let me know if I can be of any futher help.

[Adrian B]

Hi Richard…

I'm 5'7" and I find the Patrol almost slightly too long, I can stash stuff down at the foot (though it's a pain to get at) and still have covered room at the head for cooking and what not. Things can get cramped when you really need to lower it down to the ground, though this has been very rare for me. Even in blowing rain, tying the head of my bivy up is enough to keep me and my bag dry, so it would only be in very strong winds I'd need to lower it right down. In this situation things outside my bivy bag can get damp, but if you're prepared for this it's not a problem.

The Patrol is more sensitive to side on winds than head/tail on, because of the long unsupported side panels (similar to a tarp I imagine). If you make it longer, you might increase this sensitivity.

The serenity shelter would give you a tent like solution, though it might feel bit cramped compared to an actual tent? An alternative which I've been considering for a tent in buggy conditions is the Solo Trailstar/Cricket tent. It's sort of a side on Patrol, and the inner net that MLD sells would give you something more tent like than the serenity, while you could still use it without the net with a bivy instead. My impression/guess is that you might get less all-around views than the Patrol, but perhaps some more wind resistance and more covered space, and tweaking the height of the poles still gives you a lot of versatility, just like the Patrol.

edit: FYI I use the MLD Soul Bivy with the Patrol.

[Richard Hanson]

Thanks for the replies.

Currently I am using a bug bivy under a tarp but Ron is building me a Cuben Superlight bivy right now. I like the idea of not setting up the tarp when the weather is nice and spending more nights with nothing but stars overhead. My tarp is just a Grace Solo and it has worked very well but I am wanting to upgrade to Cuben. This summer my Boy Scout troop was camping in South Dakota and we got hammered by a storm with very high straight line winds coming off a lake which took out all of the boys tents. The nearest towns recorded gusts of over 80 miles per hour. I had pitched my tarp very low for the storm and all my kit was safe and dry even if the boys Eureka tents had been transformed into a mangled mass of aluminum and shredded nylon.

Philmont Scout camp does not allow tarps or bivy sacks, part of their efforts to manage bear risks, so I was thinking of a mid with an inner or the patrol shelter with an inner so that I could comply with the rules. For me, the patrol shelter looks like the better bet because I will just use it like a tarp with my bivy when not a Philmont. I am 6'2", which is why I was thinking about a little more length. If I pitch the patrol shelter low to the ground with a serenity shelter inside, I am hoping it will pass as a tent but it might still look to much like a tarp. I was afraid that the Cricket would also look to much like a tarp. I am almost certain that Philmont would allow a mid with an inner. Perhaps I will just get both, take both, and leave one in base camp depending on what I can get the ranger to accept. I have two sons in Scouts so it is not like I can't find a good home for the extra gear.

Thanks for sharing your wisdom,
Richard

[JP]

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[Adrian B]

I can't comment from experience since NZ winters aren't really that wintery. But from memory I've seen someone suggest that the silnylon has some advantage under a lot of snow because it stretches a little compared to cuben, and you wouldn't put a hole in it so easily with a snow shovel. The high-vis yellow would work well too. I'm sure Ron Bell would offer some firsthand advice if you emailed (if you do, post back here).

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