Is that because the inner fabric is not waterproof and the primaloft soaks up the condensation?
Jerven Bag
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Is that because the inner fabric is not waterproof and the primaloft soaks up the condensation?
Reading from the company site:
It is made from one layer of water tight fabric.
My uneducated guess is that it is the difference in temperature inside/outside the fabric that causes this condensation.
You might be right, the lining might soak it up, which sounds bad!
Or it might negate the temperature difference?
I do not know!
In my young and wild/creazy days when I placed my sleeping bag ( 4 season down filled Fjällräven) inside XXL sized bin liners when there was a risk of rain, condensation was present mainly when it was cold outside. I then had the sleeping bag fully closed.
Summertime, not do much condens, even with the sleeping bag open or half open.
It is made from one layer of water tight fabric.
My uneducated guess is that it is the difference in temperature inside/outside the fabric that causes this condensation.
You might be right, the lining might soak it up, which sounds bad!
Or it might negate the temperature difference?
I do not know!
In my young and wild/creazy days when I placed my sleeping bag ( 4 season down filled Fjällräven) inside XXL sized bin liners when there was a risk of rain, condensation was present mainly when it was cold outside. I then had the sleeping bag fully closed.
Summertime, not do much condens, even with the sleeping bag open or half open.
I have asked a Norwegian friend of mine. He gave me this answer about the use of the Jerven....
Hey, in my old unit the jerven with primaloft was issued to all men. The unlined one wasn't. I carried it on the outside of my patrol pack roled up. The bag it comes in is huge and not practical so we used it as a trash bag! The jerven was issued as a survival item not a sleeping bag. Every patrol in winter carried a tent per patrol and we all had sleeping bags but the jerven was so much lighter we almost always used it as a sleeping bag. But in trenning it was told to use it as a emergency shelter and that's why we carried it always. We would use it like a tented shelter in the forests for short rests or for observation. Above the tree line I would just throw it over me like a big hunting cover for short rests.
There you go!
Sent from my SM-G903F using Tapatalk
Hey, in my old unit the jerven with primaloft was issued to all men. The unlined one wasn't. I carried it on the outside of my patrol pack roled up. The bag it comes in is huge and not practical so we used it as a trash bag! The jerven was issued as a survival item not a sleeping bag. Every patrol in winter carried a tent per patrol and we all had sleeping bags but the jerven was so much lighter we almost always used it as a sleeping bag. But in trenning it was told to use it as a emergency shelter and that's why we carried it always. We would use it like a tented shelter in the forests for short rests or for observation. Above the tree line I would just throw it over me like a big hunting cover for short rests.
There you go!
Sent from my SM-G903F using Tapatalk
Ah!
Exactly what I thought about!
In my opinion the Jerven bag is sold till today because mainly hunters sit in warm clothing for a few hours in it, breathing out of the bag, perhaps just use it as a poncho-blanket with open parts during the use, and drive home after some hours and dry it out.
The poncho liner reduces condensation, because the temperature difference between inside and outside the fabric becomes lower with the liner, and - yes- the liner soaks up the condensation water.
The Snugpack Special Forces sleeping bag system works like that:
Soldier
in Ulfrotte Woolpower or more clothing
in Winter sleeping bag
in summer sleeping bag
in breathing bivvy bag.
usually the bivvy bag fabric transports the moisture outside. But should that not work perfectly, because perhaps the soldier breathes in the bivvy and sleeping bag during a part of the night, the outer summer sleeping bag sucks up the condensation water.
That happens too, should the condensation point come with falling outer temperatures inside the outer sleeping bag.
Mountaineers use VBL liners (bin bag liners) around the man in clothing. He becomes whet, the sleeping bag stays absolutely dry. No condensation inside the down filling!
If the VBL liner isn't used, with falling temperatures water condensates more and more inside the system:
At first outside the bivvy, than inside, (you can shake away the ice in the morning), than inside the outer areas of the sleeping bag.
In the Snugpack SF System I can pull inner and outer bag in this point from each other to dry the space in between the bags, the outer part of the inner sleeping bag and the whole thinner outer sleeping bag and the bivvy bag seperatly.
That is a modern System.
The Järven bag is an old System, which works nearly like this. But the fabric of the poncho doesn't transport moisture. Here you get always when you close it the same results like only in very cold weather in the Snugpack SF System.
In the eighties the western German soldier got a sleeping bag with a water tight rubber over garment. In the beginning it was fixed, in the end separate, to dry out the sleeping bag faster.
The soldiers became whet from inside every night with condensation water. Better and less than rain water, should it rain. US Poncho Concept and all old NATO Tarp-Bivvy-Ponchos from water tight rubberised fabric used the same system, with liners or sleeping bags or both or clothing inside as insulation.
The guis became whet, till Goretex was created, if they didn't sleep in their tents.
The Only other option in this time: Rubber poncho under you, cotton tent sheet or US cotton bivvy bag over you. That worked well till it rained to much.
But the armies hadn't really tent sheets in the right sizes.
German scouts had very large tent sheets which made a very good and nearly water tight cotton bivvy bag. We payed attention that they where hanging over the poncho ground sheets, so that water couldn't float on the poncho and under us. And we had to avoid lakes on us, for that the cotton fabric wasn't water proof enough.That worked very well.
Because we construct lavvus with that sheets, where we can light an open fire inside, the system is still in use.
-- like the Jerven bag!
German boy scouts love a system from the twenties of the last century. Norwegians love a system from the eighties, created by the US Army in the seventies.
Why not??? It works!
For a good nights sleep on solo camping tours modern Systems like the Snugpack special Forces Sleeping bag System or Hilleberg survival Bivanorak are the better and especially lighter options!
In the cotton-tent-sheet-bivvy I slept very well too, but it was relatively heavy. Only an option today, if I have the four sheets together with my friends, to construct the fire heated lavvu!
(See for the tent the video "Kohtenaufbau auf Zeit")
That's what I think currently about it.
In the beginning of this thread stands a link to a sold out cheaper copy of the Järven bag made from breathing fabrik!
That would be a newer system. But the Norwegian hunter doesn't need a newer system. And so they sell the old one with success.
For short intermissions or an evening while hunting that surely works fine.
And yes: How I wrote in the beginning, I slept round about hundred times in a rubber poncho bivvy bag and got always a whet sleeping bag.
I knew it and did it always once more and once more, if I was on a way without cotton tent sheet, to save the weight.
If you are used to harder weather, if you run around in the snow in Bavarian leather shorts, if you are used to swim in incredibly cold water like Scandinavians do it all over the year, or usually hopp out of the Sauna nacked in the snow, it's no problem to sleep in a rubber bivvy bag. The complete german army did it for may be 20 years, nearly every german man did it!
In the fifties in german youth hostels in some Bavarian forests the cold water tab was reserved for the girls, the boys washed themselves in the snow. On our hikes in spring and autumn we didn't visit heated swimming halls, we jumped in ice cold water, even in the nineties, and better german boy scout groups do it till today.
Yes, uncomfortable. But somehow funny too! Why not!
Germanic tribes aren't made from sugar!
And so can survive a rubberised bivvy poncho in Norway.
In the morning they light a fire and dry it out and it's fine!
Exactly what I thought about!
In my opinion the Jerven bag is sold till today because mainly hunters sit in warm clothing for a few hours in it, breathing out of the bag, perhaps just use it as a poncho-blanket with open parts during the use, and drive home after some hours and dry it out.
The poncho liner reduces condensation, because the temperature difference between inside and outside the fabric becomes lower with the liner, and - yes- the liner soaks up the condensation water.
The Snugpack Special Forces sleeping bag system works like that:
Soldier
in Ulfrotte Woolpower or more clothing
in Winter sleeping bag
in summer sleeping bag
in breathing bivvy bag.
usually the bivvy bag fabric transports the moisture outside. But should that not work perfectly, because perhaps the soldier breathes in the bivvy and sleeping bag during a part of the night, the outer summer sleeping bag sucks up the condensation water.
That happens too, should the condensation point come with falling outer temperatures inside the outer sleeping bag.
Mountaineers use VBL liners (bin bag liners) around the man in clothing. He becomes whet, the sleeping bag stays absolutely dry. No condensation inside the down filling!
If the VBL liner isn't used, with falling temperatures water condensates more and more inside the system:
At first outside the bivvy, than inside, (you can shake away the ice in the morning), than inside the outer areas of the sleeping bag.
In the Snugpack SF System I can pull inner and outer bag in this point from each other to dry the space in between the bags, the outer part of the inner sleeping bag and the whole thinner outer sleeping bag and the bivvy bag seperatly.
That is a modern System.
The Järven bag is an old System, which works nearly like this. But the fabric of the poncho doesn't transport moisture. Here you get always when you close it the same results like only in very cold weather in the Snugpack SF System.
In the eighties the western German soldier got a sleeping bag with a water tight rubber over garment. In the beginning it was fixed, in the end separate, to dry out the sleeping bag faster.
The soldiers became whet from inside every night with condensation water. Better and less than rain water, should it rain. US Poncho Concept and all old NATO Tarp-Bivvy-Ponchos from water tight rubberised fabric used the same system, with liners or sleeping bags or both or clothing inside as insulation.
The guis became whet, till Goretex was created, if they didn't sleep in their tents.
The Only other option in this time: Rubber poncho under you, cotton tent sheet or US cotton bivvy bag over you. That worked well till it rained to much.
But the armies hadn't really tent sheets in the right sizes.
German scouts had very large tent sheets which made a very good and nearly water tight cotton bivvy bag. We payed attention that they where hanging over the poncho ground sheets, so that water couldn't float on the poncho and under us. And we had to avoid lakes on us, for that the cotton fabric wasn't water proof enough.That worked very well.
Because we construct lavvus with that sheets, where we can light an open fire inside, the system is still in use.
-- like the Jerven bag!
German boy scouts love a system from the twenties of the last century. Norwegians love a system from the eighties, created by the US Army in the seventies.
Why not??? It works!
For a good nights sleep on solo camping tours modern Systems like the Snugpack special Forces Sleeping bag System or Hilleberg survival Bivanorak are the better and especially lighter options!
In the cotton-tent-sheet-bivvy I slept very well too, but it was relatively heavy. Only an option today, if I have the four sheets together with my friends, to construct the fire heated lavvu!
(See for the tent the video "Kohtenaufbau auf Zeit")
That's what I think currently about it.
In the beginning of this thread stands a link to a sold out cheaper copy of the Järven bag made from breathing fabrik!
That would be a newer system. But the Norwegian hunter doesn't need a newer system. And so they sell the old one with success.
For short intermissions or an evening while hunting that surely works fine.
And yes: How I wrote in the beginning, I slept round about hundred times in a rubber poncho bivvy bag and got always a whet sleeping bag.
I knew it and did it always once more and once more, if I was on a way without cotton tent sheet, to save the weight.
If you are used to harder weather, if you run around in the snow in Bavarian leather shorts, if you are used to swim in incredibly cold water like Scandinavians do it all over the year, or usually hopp out of the Sauna nacked in the snow, it's no problem to sleep in a rubber bivvy bag. The complete german army did it for may be 20 years, nearly every german man did it!
In the fifties in german youth hostels in some Bavarian forests the cold water tab was reserved for the girls, the boys washed themselves in the snow. On our hikes in spring and autumn we didn't visit heated swimming halls, we jumped in ice cold water, even in the nineties, and better german boy scout groups do it till today.
Yes, uncomfortable. But somehow funny too! Why not!
Germanic tribes aren't made from sugar!
And so can survive a rubberised bivvy poncho in Norway.
In the morning they light a fire and dry it out and it's fine!
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Yes, you are correct, these are emergency equipment.
A poncho is too. Cover yourself in case of a gas attack, to cover yourself for the hour you manage to sleep.
A plastic binliner is not even that, that equipment is pure craziness!
It is the masochist in every bushrafter ( including scouts) that make them so popular!
The worst with getting your down sleeping bag wet is that they start moulding after a week or two.
I have lost several to this.
A poncho is too. Cover yourself in case of a gas attack, to cover yourself for the hour you manage to sleep.
A plastic binliner is not even that, that equipment is pure craziness!
It is the masochist in every bushrafter ( including scouts) that make them so popular!
The worst with getting your down sleeping bag wet is that they start moulding after a week or two.
I have lost several to this.
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Having delved into the jervan bag a little more since this thread was started I think if I had one it would sit around for ages and get used very very rarely and almost never for sleeping in since I already have better and lighter alternatives........but I still kinda want one and that cheaper arktis version will probably pop up on here one day in stock somewhere and I'll impulse buy it in a weak moment lol
Incidently and kinda connected. I do have a hill people gear mountain Serape and jacks R better poncho quilt that do get used and I'm quite taken with both of them
It's not the same as a jervan bag at all but similar multi use type garments
Incidently and kinda connected. I do have a hill people gear mountain Serape and jacks R better poncho quilt that do get used and I'm quite taken with both of them
It's not the same as a jervan bag at all but similar multi use type garments
Yes, but if you like to become whet during the night a used rubberised german or Austrian poncho for 20€ in combination with a used US Army poncho liner or the low quality Miltec poncho liner would surely be a fantastic option too.
And this ponchos are real survival ponchos: They had been called "ABC Ponchos", what means, they are recommended against nuclear, biologic and chemical attacks!
I am totally convinced, that this rubber sheet works very well if somebody should throw a nuclear bomb on you.
And this ponchos are real survival ponchos: They had been called "ABC Ponchos", what means, they are recommended against nuclear, biologic and chemical attacks!
I am totally convinced, that this rubber sheet works very well if somebody should throw a nuclear bomb on you.
We had to practice with the soldiers in ABC preparedness with ponchos. For us officers, that meant once every 15 months.
The ABC specialist in our unit was not the sharpest knife in the drawer ( hence why he became an ABC spec)
And it was always very funny to hear him trying to get a clever, good sounding answer on questions like:
How many kilotons can it take?
How long can it withstand 100 000C temp?
If I need to take a crap during a biological attack, can I use a corner of it?
All of us had to be able to spend 6 hours underneath one, a simulated gas and bio combined attack.
We sprayed teargas and a coloured oil.
It was always somebody that did not put on the gasmask properly, or got the oil on the skin. Failed and had to do it again next time.
We all felt it was 100% pointless. The worst was for me that I could not have a cigarette.
Not 100% off topic, as that was the main reason these ponchos are designed the way they are. ABC protection. Second permitted use an emergency shelter.
The ABC specialist in our unit was not the sharpest knife in the drawer ( hence why he became an ABC spec)
And it was always very funny to hear him trying to get a clever, good sounding answer on questions like:
How many kilotons can it take?
How long can it withstand 100 000C temp?
If I need to take a crap during a biological attack, can I use a corner of it?
All of us had to be able to spend 6 hours underneath one, a simulated gas and bio combined attack.
We sprayed teargas and a coloured oil.
It was always somebody that did not put on the gasmask properly, or got the oil on the skin. Failed and had to do it again next time.
We all felt it was 100% pointless. The worst was for me that I could not have a cigarette.
Not 100% off topic, as that was the main reason these ponchos are designed the way they are. ABC protection. Second permitted use an emergency shelter.
The German Army didn't use it as rain poncho. They used the tent sheet for rain protection before they got Goretex suits.
That's the reason, why now a days we can buy this stuff in nearly unused conditions.
Most old US Army ponchos we are offered are really used, because they used it as rain protection too.
That's the reason, why now a days we can buy this stuff in nearly unused conditions.
Most old US Army ponchos we are offered are really used, because they used it as rain protection too.
They are larger than most new stuff.
They are 210x165 cm.
That means, folded in a half that's large enough as a bivvy bag:
210x 82,5 cm. The snaps need some space, and that open line should show to the ground. Here you can use round about 205x80 cm
The new ponchos with 210x 150 cm or less let you only 205x 72cm and that is TO SMALL AS A BIVVY BAG. Some have only 145cm!!!
The new ones do not cover the arms.
The Bundeswehr Poncho covers the arms of a person who is 165 cm tall.
But it works for me too, I am 185cm tall.
The Holland Army poncho is a bit larger. I think it fits perfectly with the Snugpack Jungle Bag as the far better poncho liner.
But I never got the Dutch one.
As ultra light option as poncho tarp I only know the a bit to short but wide enough Defcon 5 poncho, it has 165 cm too, but is only 190 or 200cm long. I forgot it. Would work as an emergency bivvy bag. It has a Nato Stock number.
It weights only 400g. In combination with Snugpack Special Forces Bivvy Bag 340g the lightest well working option I know.
You can take the Defcon 5 Poncho as raincoat an tarp, with Snugpack Special Forces Bivvy bag and one of the Special Forces Sleeping bags that works well, the SF 1 is very light and packs very compact.
The Robens Couloir Sleeping bags I didn't try out.
I think that will work too for experienced people.
I prefere Zipper over Zipper!!! Robens Couloir ultra light sleeping bags have central zippers like SF1 or 2 and the SF bivvy bag and nearly the same shape or cut.
That's an interesting summer option for example with the lightest Robens.
They are 210x165 cm.
That means, folded in a half that's large enough as a bivvy bag:
210x 82,5 cm. The snaps need some space, and that open line should show to the ground. Here you can use round about 205x80 cm
The new ponchos with 210x 150 cm or less let you only 205x 72cm and that is TO SMALL AS A BIVVY BAG. Some have only 145cm!!!
The new ones do not cover the arms.
The Bundeswehr Poncho covers the arms of a person who is 165 cm tall.
But it works for me too, I am 185cm tall.
The Holland Army poncho is a bit larger. I think it fits perfectly with the Snugpack Jungle Bag as the far better poncho liner.
But I never got the Dutch one.
As ultra light option as poncho tarp I only know the a bit to short but wide enough Defcon 5 poncho, it has 165 cm too, but is only 190 or 200cm long. I forgot it. Would work as an emergency bivvy bag. It has a Nato Stock number.
It weights only 400g. In combination with Snugpack Special Forces Bivvy Bag 340g the lightest well working option I know.
You can take the Defcon 5 Poncho as raincoat an tarp, with Snugpack Special Forces Bivvy bag and one of the Special Forces Sleeping bags that works well, the SF 1 is very light and packs very compact.
The Robens Couloir Sleeping bags I didn't try out.
I think that will work too for experienced people.
I prefere Zipper over Zipper!!! Robens Couloir ultra light sleeping bags have central zippers like SF1 or 2 and the SF bivvy bag and nearly the same shape or cut.
That's an interesting summer option for example with the lightest Robens.
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