breathing inside a bivy shelter [Archive]

iacco

11-19-2009, 06:08 AM

I just got a british DPM bivouac shelter like this:

http://i49.tinypic.com/14uur7l.jpg

It looks to be an Arktis and it is claimed to be waterproof and breathable.
When I close the zipper, I don't have any holes to breath through.
Leaving the zipper slightly opened to ensure breathing the shelter will loose the waterproof capability. It can happen especially with heavy rain and strong wind.
It doesn't have any net and it means that if I leave it opened a bit, some insect (mosquito ect) can get inside.
The question is: can I sleep in such bivy shelter completely closed? In my mind . . . no!
Another question: the seams were taped and now the tape is somewhere raised, how do you suggest to fix it? Glueing it?

Many thanks

Creeper

11-19-2009, 06:19 AM

Yes , zip it up and snooze like a bear. its probably Goretex (hopefully), no net or screen at the entrance ? make one.

You will be fine.Start out in your backyard at first then go big.

I always bring 6 pack of beer and a good book to read.

have fun.

Muddlers

11-19-2009, 06:23 AM

You're lucky to have one of them.

I still love my basha, and will see it's lovely use in Wales this Friday :)

2495

11-19-2009, 07:41 AM

Mate - climb in, zip it up and snooze away. Good solid bit of kit and well worth a bit of cash to have instead of a massive tent.

Greek soldier

11-19-2009, 07:55 AM

Definately Gore-Tex.

I really wanted to buy this specific bivy, but I went for the Snugpak Stratosphere for the reasons you mentioned. Definately not the same quality as the SAS Bivy or the Carinthia ones.

You need a basha or a poncho if you're going to leave the bivy unzipped. Quite a disadvantage not having a mesh vent...

For mosquito protection, I believe you can plait a net.

Connaught Ranger

11-19-2009, 08:18 AM

By the model with the built in aqua-lung!rofl:profl

iacco

11-19-2009, 08:36 AM

Thanks you for the answers.
I got this used bivy because it looks to be . . . solid and well working.
I'll test it this weekend during a military exercise.
The fabric is for sure waterproof but it looks to be breathable because when I rolled up the air exhaled from the bivy and I could packed it very tight.
To tell the truth such bivy has a hole (created for ventilation?) and I think to put a fabric on it making a sort of "air intake" as done in most tents.
About the net I will try to sew a velcro strip on the inside of the zipper (without sewing on the waterproof fabric) to put the net when I need.
And when it is raining, I'll use the poncho to make a roof over the zipper.

Any suggestion for the taped seams?

flanker7

11-19-2009, 09:01 AM

We are issued Carintis Observer Bivy Shelter and I always leave it a bit open. It mekes me feel better. All other closed it up though :-)

dave81

11-19-2009, 09:02 AM

It's made of fabric, not rubber. It's not airtight like a balloon. Are you claustrophobic? Because I can't see how or why this question of "not being able to breathe inside a bivy cover" would even come up.

LineDoggie

11-19-2009, 09:05 AM

Seam Sealer:

http://www.amazon.com/McNett-Seam-Sure-Sealer/dp/B000696D7O

iacco

11-19-2009, 09:12 AM

It's made of fabric, not rubber.
Actually, it is "something" between fabric and rubber. It has a liner that looks like fabric. tightly spread on this there is a goretex-like membrane that is similar to rubber.

Are you claustrophobic?

No, I'm not. I'm just concerned about the quality of the air inside. In my opinion the exhaled air from the body can't exit very well from the bivy and the carbon dioxide will raise to unacceptable level.
As I haven't receive any answer from Arktis I even interrogate one other brand that makes something similar and they answer: yes! There is the risk of suffucation.

As this is a quite common piece of equipment (especially for brits) I posted this new thread to learn other's experience.

Seam Sealer:

http://www.amazon.com/McNett-Seam-Sure-Sealer/dp/B000696D7O

Thank you but the seam sealer works over the seams and don't stand a "water columns" like goretex do.
I intend to glue the tape on the goretex-like membrane so I need to know what glue (not sealer) sticks on goretex.
The problem is that goretex is made of teflon and teflon is one of the most difficult material to glue.

Thanks anyway

Zarak

11-19-2009, 09:29 AM

...its not as though it is air-tight. People regularly sleep in bivouac shelters which are zipped up without suffering brain damage. :|

iacco

11-19-2009, 09:39 AM

People regularly sleep in bivouac shelters which are zipped up

This is exactly what I wanted to know...

Thank you very much

Greek soldier

11-19-2009, 11:11 AM

At the beginning zip it up completely.

If you see that you feel uncomfortable with the air, then leave the zipper some 5-10 cm open. Since you're going to use a poncho for shelter, you'll be fine.

Can you post more pictures of your bivy? The above pic doesn't show much.

Thumpsquid

11-19-2009, 11:15 AM

You're lucky to have one of them.

I still love my basha, and will see it's lovely use in Wales this Friday :)
well good luck, and bring an Aqualung, because this Friday ( 20th of November 2009) Wales is going to be underwater.

Trunk_Monkey

11-19-2009, 04:31 PM

All bivvies are a little claustrophobic, and it would not make sense to make a bivvie, which when zipped up, would not allow you to breath. If it is goretex, there tends to be a nylon layer on the inside and outside, in between which is sandwiched the ptfe (in this case goretex). So no, it is not rubber and yes good ol' duct tape will adhere to it for a while if you need an expedient method to fix the seams. As for the bug net, sewing velcro on will of course leave tiny holes through which water can enter, so you may want to seal this on the outside. As for permanently fixing the tape that is peeling, there are specific tent seam sealing kits, easily found on google. Just look up "seam tape repair kit". There are also gore patch kits that are easy to find. Oh, and the stuff in LineDoggie's link will adhere to the nylon for sure. Good luck!

iacco

11-20-2009, 03:08 AM

Thank you.
In a few days I'll post some live pictures of the bivy (I'm having a military exercise).
I'll think how to set up a velcro sewing inside the side of the zipper (not to make holes in goretex).
This summer, going trekking in Rockies (Canada) I got the original seam sealer: I'll use it to fix the tape to the goretex.

Thank you everybody

Soldat_Américain

11-20-2009, 03:24 AM

You could have just built one with sticks and such using a poncho as the flap.

siquq

11-20-2009, 10:16 PM

I use an Integral Designs South Col bivy, which lies low to the face when zipped up tight. I have used it from -45C to about 5C in blowing snow and even rain, completely zipped up, and had no trouble getting enough air through the fabric.

Creeper

11-20-2009, 10:43 PM

I have an old Integral Designs bivy, US grn camie, w a fly net at the entrance. Great piece of gear, good head rm etc,, kept dry and warm w / o probs.

One nite had soup w blk beans and I thought that bivy was going to explode w the gas expansion inside. I lived.

iacco

11-24-2009, 03:30 AM

Manc

11-24-2009, 05:42 AM

Glad to see you've made it safe ;) ...and it's always a pleasure to see the old Telo Mimetico pattern popping out every now and then. I think I still have a couple of them somewhere.

Greek soldier

11-24-2009, 07:54 AM

the exercise finished and I can now post some pics. Note the other tent of a mate.
The altitude was around 1000mt and the weather very good so I couldn't try the thermal capabilities of the shelter. Nevertheless I found such shelter comfortable and . . . probably breathable even if I left the zip unzipped for 5cm.
The only problem using this shelter is to provide a roof in case of rain but just to have a place to dress/undress without filling the shelter of water. In those cases a poncho used as a basha will probably works fine.

Next step to do: fix the shelter sealing the peeled tape with the "seam sealer".

Note that I had to fix the shelter on the ground using tent pegs and a cord to keep the shelter tight.

Well, you can't have it all in one , can you? p-)

The best combo is a bivy bag with a poncho as a shelter, also for protecting your rucksack/boots/equipment. You could have brought a poncho and connect it with your colleague's one.

Yes, you have to fix it to the ground for maximum comfort (you have some space in between for turning around while sleeping). The good thing is you have also the option to set it up in seconds even without them.

If you want something larger than a bivi, you can look for a One-Man Tent. But keep in mind it roughly weights some 3 kilos, which is a lot if you regularly walk from point to point. And quite bulky when packed.

Since this thread is about breathability, did you feel uncomfortable while sleeping?

2495

11-24-2009, 08:16 AM

If you want something larger than a bivi, you can look for a One-Man Tent. But keep in mind it roughly weights some 3 kilos, which is a lot if you regularly walk from point to point. And quite bulky when packed.

Holy sh1t mate - can tell your not into ultra light / fast hiking / expeditions. If any one needs a one man tent and gets sold some thing over 1.8 Kg, they have been weight robbed!

That aside, I agree that a one man tent is a better way to go than a bivvie unless theres an absolute need for it.

iacco

11-24-2009, 08:23 AM

you can look for a One-Man Tent. But keep in mind it roughly weights some 3 kilos, which is a lot if you regularly walk from point to point. And quite bulky when packed.

I find the Ferrino Lightent to be good and very light (1,55kg). It even comes in dark green colour. The profile is very low from the ground but the room inside is much bigger than the bivy.
On the other hand "my" bivy shelter in complete configuration (stuff sack included) weight almost 1.7kg (that is a lot!).
The advantage of the bivy is that I can use it not only like "a tent" but also like a bivy bag. That means I don't have the need of a smooth surface and I could use it even without the frame in every situation.
Therefore: the bivy shelter is quicker to set up, tougher and more flexible than a modern ultralight tent, on the opposite side is relatively bulky and heavy.

Since this thread is about breathability, did you feel uncomfortable while sleeping?
No, I didn't. Anyway, as I wrote, I avoided to risk leaving the zipper 5cm unzippered.

bye

Greek soldier

11-24-2009, 08:40 AM

The one-man tent I'm talking about is the Tasmanian Tiger one which is 2.6 kgs, heavier and more expensive than the Ferrino.

The Ferrino I was told has some problems with the waterproofness of the floor.

A tent has the advantages the bivi bags don't have (roomy space for rucksack and other equiment, dress/undress, etc.).

My Snugpak Stratosphere when packed is roughly 1.3 kgs 'cos it has 6+1 steel pegs, alongside the 2 aluminum poles. Without the pegs is less than a kilo.

Sneeuwbaard

11-24-2009, 09:48 AM

My bivi is identical to the one on the picture, and I've never experienced any breathing problems. (Gore-tex works great)

I do have a very fine and effective mosquito net in it though, and I must say that I wouldn't leave the zipper open if it didn't have one, depending on the location ofcourse.
Slept without mosquito net one time, the bug bites (and sounds!) were really annoying. (Not that easy to turn around or itch.)

You can sleap with the zipper open ofcourse, and as long as the rain & mosquitos stay away it will be an dry sleeping place.

It's fantastic seeing it only weights about 600 gram and doesn't need alot of space.

Greek soldier

11-24-2009, 01:14 PM

AFAIK the Dutch Army bivi bags are license-built (made in Spain?) Carinthia bivi tents

http://www.genuinearmysurplus.co.uk/products/detail/rowid=1715

http://www.lutonarmysurplus.co.uk/images/miscellaneous/misc128L.jpg

Sneeuwbaard

11-24-2009, 04:27 PM

Greek soldier

11-24-2009, 04:52 PM

Oh, I see. Thanks for the photo. :-)

seraosha

11-24-2009, 05:36 PM

I feel for you guys...I'm so addicted to forest camping that I'd be despondent without my hammock. But that bivy (heck all of them) look great. Glad to hear about the breathability as well, as I've often wondered.

iacco

11-25-2009, 04:42 AM

@ Greek soldier: The Dutch Army bivy bags looks similar to the british ones (exept for the L-shaped zip and a second frame near the feet).
The shelter you are using seems to be more comfortable than mine: the frame keep the fabric away from the body (and this should avoid condensation drops to go to the sleeping bag). For the rest it looks to be used completely zippered like mine, do you confirm?

@seraosha: the basha/tarp (as roof) and the hammock work fine but only in the temperate climates (with no wind!). Moreover they need something to be hanged to (trees or similar 3m far from each others).
The flexibility of the british/dutch bivy shelters allow them to be used (without frames) as a bivy sac inside the hammock even when it is cold. Anyway, you gave me the idea to test my shelter on my hammock . . . next time. . .

Thanks everybody

IACCO

Greek soldier

11-25-2009, 07:18 AM

@ Greek soldier: The Dutch Army bivy bags looks similar to the british ones (exept for the L-shaped zip and a second frame near the feet).
The shelter you are using seems to be more comfortable than mine: the frame keep the fabric away from the body (and this should avoid condensation drops to go to the sleeping bag). For the rest it looks to be used completely zippered like mine, do you confirm?

Yes. Mine has a mesh vent at the back and a mosquito net at the front (can also be used as second mesh vent), except that it's not Gore-tex.

Never had a problem breathnig when fully zipped.

Without the pegs

http://www.woodlife.co.uk/2008/04/03/snugpak-stratosphere-hooped-bivi-bag-initial-review/

With the pegs

http://www.snugpak.com/forum/showthread.php?t=56

(not my pics)