2 person sleeping bags

[salbrecher]

I'm wondering if anyone has any experience using commercially available 2 person synthetic sleeping bags or has made there own? If so what company made yours and how well did it work for warmth compared to company ratings? what was the weight and price? If you made your own, how well did it work and are there any things you would do differently if you made another one? what was the weight of it and what synthetic fill did you use? looking for one in the -4 celcius to -9 celcius range. anyone here have any experience using one on a route? good or bad experience? More of an alpine thing and less of a cuddling with the girlfriend type bag

 

stefan

[PLC]

My wife and I just zip our sleeping bags together. We each have 0 degree bags, and we've found we sleep significantly warmer with the bags zipped together. If it gets really cold, we add a dog.

[rob]

My wife and I have a pair of synthetic 15F bags that zip together (one is a lefty and one is a righty). No complaints yet, and they work well-enough by themselves. They zip together nice even though hers is regular and mine is long.

 

I don't remember the brand, I could check if you're interested.

 

I have a friend who used a "permanent" two-person bag on his PCT trip. I think it was this one. He loved it.

Edited January 7, 2007 by robmcdan

[Dechristo]

Is there a chart for determining what size dog to use with differing sleeping bag temp ratings against outdoor temps?

[TrogdortheBurninator]

We have a regular and a long that zip together. I think this is fairly common in the industry for long and regular to have opposite zippers. I actually never found it warmer because it is harder to seal off.

[salbrecher]

PLC, can your recomend a lightweight alpine dog? 2 bags zipped together is not what I am looking for since they weigh the same as 2 sleeping bags and are colder due to more airspace than a single despite more body warmth. A 2 person bag weighs less than 2 sleeping bags and is warmer.

[genepires]

I have used a down bag that was made to sleep two people from feathered friends, can't remember the model right now. It is a sort of rectangular bag that zips out to a fairly rectangular shape (zipper goes out all the way across foot section), with a nylon piece that zips into the bag to allow two to sleep under the single bag. There are sleeves for the pads to go in to keep you off the ground and also prevent one person from "stealing all the covers".

 

I see you are asking about synthetic bags, but I bet you could find a synthetic bag to work with this feathered friends doubler for a lightweight sleeping system. They have two of this type, one is lighter than the other. Now finding a good cover (double bivy?) for this is a struggle.

[Mark_Husbands]

Nunatak has some pretty fancy ones.

 

http://www.nunatakusa.com/Sleeping_Bag_Dual_Alpinists_Sleeping_Bag.htm

 

seems like a pretty good hood on your parka would be important.

[Couloir]

Big Agnes? Perhaps they have a bag that isn't necessarily a "2-person sleeping bag" but may be able to offer something in between that has a favorable weight.

[Jedi]

My partner is going to build one in a month or two. Probably looking at PG Delta insulation or PL. Design will be the same as Nunatak's Arc double bag... http://www.nunatakusa.com/Sleeping_Bag_Dual_Arc_Alpinists_Sleeping_Bag.htm

He has made one before and said it worked quite well. This one will have more insulation.

If it pretty cold, then a parka (syn fill) with a hood is important and synthetic fill pants help.

 

The pad system is pretty important too.

 

Rating......that's a tough one.

 

[Kevin_Matlock]

Saw Steve House when he was in Salem talking about the Rupal Face climb. He talked a little about how he makes his own double bags.

 

Found a little blurb related to this...

http://www.getoutdoors.com/goblog/index.php?/archives/1083-Saving-Weight-in-the-Mountains-Nunatak-Half-Sleeping-Bag.html

 

[PLC]

PLC, can your recomend a lightweight alpine dog?

 

Well, the Siberian Husky is essentially zero weight, since he'll be able to walk anywhere you can climb, but I wouldn't recommend trying to put one in your sleeping bag. I tried putting one in a tent once, and even that didn't work out too well (tent destroyed in less than 60 seconds). Apparently, they don't take to confinement.

 

[Marko]

A fairly easy way to do it is to cut a vee shaped piece of light fabric and sew a separating zipper to it so that it zips into your full zip mummy bag. (I believe Senor House has mentioned this idea.)

 

So you unzip the mummy bag completely and zip in the vee to create the bottom of a 2 person bag. I've used this a bunch of times and it's light, warm, and cramped as hell. 2 1/4 lbs for a full on winter 2 person bag. It helps if the bag is a little long so you can bunch it around your shoulders.

 

I also bought a synthetic quilt thing made by Golite and sewed on a windproof bottom and hood. It's about 3 1/2 lbs and fits 2 pretty comfortably. 3 of us used it in a bivy tent for a few nights up in Alaska. Worked out OK.

 

Obviously a route with tiny or no ledges pretty much kill the double bag idea.

[featheredfriends]

Stefan, can you explain your reasons for wanting a synthetic bag? For the application you describe, a synthetic bag would be bulkier and heavier than a down bag, both of which are considerable drawbacks for alpine climbing. I would be greatly surprised if you found a -9 C synthetic two-person bag that weighed less than 1700g/3.75 lb.

 

The main reason most people seem to want synthetic bags these days are because of the old "it keeps you warm when it's wet" story. Now that shell fabrics (like eVent) have reached the point where they are waterproof, highly breathable, and reasonably light, that is a harder argument to make. Furthermore, since synthetic bags are much less durable than down bags, that is another disadvantage to them.

 

Regardless of fill type, the 2-person bag design is inherently inefficient in colder weather (i.e. below -9 C). The enormous opening at the top of the bag doesn't do a great job of preventing warm air loss, and in the interest of saving weight a lot of 2-person bags forgo the ever important zipper draft tube.

 

That being said, Feathered Friends makes 2-person sleeping bags rated to as low as -20 F. This sounds a bit excessive for your needs. If your intended use for the bag was summertime alpine climbing below 4200m in the lower 48 or Canada, then a Penguin model rated to 20 F/ -6.7 C and an ultralight groundsheet would be a comfortable option. Total combined weight is 3.4 lb. or 1560g.

 

 

 

The total cost for a Penguin 20 with groundsheet is in the neighborhood of $460. Not the cheapest, but you get the premiums of excellent water resistant fabric, 850+ fill down, and the ability to add hoods to the bag later. If you don't want the hoods we can make it without the extra zippers and that would save another couple ounces.

 

Link to Feathered Friends Penguin sleeping bag

[salbrecher]

Marko, thanks for the idea, a zipped in light synthetic v shaped piece of fabric sounds perfect and light. Featheredfriends, even with waterproof coatings down bags still get wet from the inside from brought in snow on clothes, spindrift and body vapour. Durability of synthetic is not an issue as it will hopefully be used only a few nights. My down dryloft -30 bag was 100% useless after 4 of 8 days on a climb last year in alaska. even a 0 degree celcius synthetic would have been far better. Lesson learned.

[mattp]

A bit off topic, perhaps, but I have always felt that zipping bags together made both participants colder (though some but not al of my girlfriends before marriage and my wife now may disagree). There is a lot of extra space in the bag, and it is inefficient. Part of the problem lies with the fact that it is difficult to close off the top of the bag around your necks and shoulders, and it helps to use exta clothing - maybe down jackets - as a baffle.

[chris]

Marko, thanks for the idea, a zipped in light synthetic v shaped piece of fabric sounds perfect and light. Featheredfriends, even with waterproof coatings down bags still get wet from the inside from brought in snow on clothes, spindrift and body vapour. Durability of synthetic is not an issue as it will hopefully be used only a few nights. My down dryloft -30 bag was 100% useless after 4 of 8 days on a climb last year in alaska. even a 0 degree celcius synthetic would have been far better. Lesson learned.

 

Sal, even with a synthetic bag you'll still get the freezing vapor inside the bag in the conditions you describe. FF's comment about durability is in the long-term, not a few short nights. I use a -20 bag on three week Denali climbs annually without incidents.

[JayB]

I have also found that doubling up sleeping bags was significantly colder than sleeping in single bags.

[salbrecher]

Mtnfreak, yes you'll still get freezing condensation inside a synthetic, but it will still be warmer than a down bag with frozen condensation. Durability, as i said, is not an issue. It would only be used a few nights for one route and hopefully never again. Jay, as said before, we are not looking to zip together 2 full bags for the reasons mentioned above. Please read above posts before posting people...

[Mon_Col]

If you've got the time and the energy, making your own two person synthetic quilt is a possibility. http://www.rayjardine.com has some that they have used in Antarctica and Greenland. I haven't made the quilt but I've made the tarp and am really happy with it. I believe the collar on the quilt helps with the draft problem. I think the kit costs about $70. However, if you're only going to use it once then it may not be worth the time.

[Jedi]

I problem I have found, with down bags in arctic conditions, is they work well if you have the opportunity to dry them out. On longer routes, you pack them 1st thing in the morning and usually unpack them and dive in at the end of the day. They do not get a chance to dry out and the loft is greatly reduced. As the down collects moisture, it gets heavier.

 

So, the longer the route, the heavier it gets, at some point surpassing the weight of the synthetic bag.

Isn't synthic insulation a little more hydrophobic?

 

Sure, for an open bivy, Epic, Event and the like works great. But those material do not breathe as well as LESS waterproof materials. The more breathable shells are also lighter and compactable.

The problem is moisture given off by your body that ends up in the insulation. From the inside out.

So you want that moisture to pass as easily as possible, right?

 

So your insulation gets more damp as the days go on. You are also getting higher where it is getting colder, as luck would have it. This is where your insulation needs to be working it's best and it's at it's worst.

 

What unpacks worse, wet down or wet synthetic insulation? (I don't have experince with wet synthetic)

 

If it is only a couple days (three at the most), I prefer down. Anything longer than that synthetic starts looking more attractive. UNLESS you have part of a day you can "dry" the bag out (in a sun warmed tent or on the tent).

This option is route dependant and not really an option on a route you are carrying a double bag.

 

This is why synthetic parkas are nice. It's your one piece you can pretty much count on.

 

Whatever you end up doing, let us know.

 

Sounds like someone needs to make a parka and double bag combination that zip together. Maybe the top of the bag zips to the shoulder hood area of the parka (horribly complex).

Maybe a draw string system that you put your heads in and it snugs the top of the bag where the most heat loss is taking place.

 

 

 

Jedi

[genepires]

Hey salbrecher, maybe you could give the good folks at integral designs a call. Maybe they could whip up a double bag for you to your exact specs?

 

And Jedi, maybe I am old and tired but three days on a route? Are there more than one colin type out there?

[Jedi]

 

And Jedi, maybe I am old and tired but three days on a route? Are there more than one colin type out there?

 

I wish I was Colin's age but I'm pretty slow/old (I'm 39 now).

But I'm hoping we get a chance at the Cassin and can climb it in a "respectable time".

Dag, if I was 21..........alas...........I might would be on Colin's heels (HA) or most likely, in his dust a little way back. hehehe

 

Anyway........

I was comparing a route like the West Buttress vs something like the Infinite Spur when talking about synthetic & down insulation and more than 3 days on a route.

[featheredfriends]

I problem I have found, with down bags in arctic conditions, is they work well if you have the opportunity to dry them out. On longer routes, you pack them 1st thing in the morning and usually unpack them and dive in at the end of the day. They do not get a chance to dry out and the loft is greatly reduced. As the down collects moisture, it gets heavier.

 

Jedi, in theory your point makes sense, but in practicality my experience is that down dries out quickly. Over 4 separate 4 to 6-day trips in the N Cascades last year I tested out bag prototypes in conditions from 20 degrees with snow to 4 degrees with rain. Even when my bag was damp from repeated entry and exit from a Bibler in the rain, each morning I awoke to a dry bag because my body heat had dried it out during the night. Adding a hot water bottle to the bag accelerates the process. This is an easy thing to do once you make camp and get the water going. Plus it is nice to have a pre-heated bag to climb into at night.

 

One difference between synthetic fiber insulation and down that many people don't realize is that down is much more breathable. This is one reason why a zero degree down bag is more comfortable on a +40 night than a zero degree synthetic bag. More breathability means better ability to transport moisture out of the insulation. A slightly, or even moderately, down bag is easy to dry out, even in wet conditions. The catch is that there is a tipping point past which, if you get your down TOO wet, it is hard to recover from. Getting your bag this wet, however, is pretty hard to do and is usually the result of an unforeseen catastrophe or incompetent gear management.

 

Sure, for an open bivy, Epic, Event and the like works great. But those material do not breathe as well as LESS waterproof materials. The more breathable shells are also lighter and compactable.

The problem is moisture given off by your body that ends up in the insulation. From the inside out.

So you want that moisture to pass as easily as possible, right?

 

Correct. Epic and Event work great for an open bivy, but their benefits are equally valuable on long trips in a tent where prolonged exposure to condensation can be a problem. Another problem is cold conditions where water vapor freezes to the tent walls and creates an indoor blizzard. It's true that neither Epic nor Event breathe as well as untreated taffeta nylon, but just because they are less breathable doesn't mean that these fabrics are not breathable enough. Have you ever slept in an Epic or Event shelled bag for a few nights? The breathability of these fabrics is pretty darn good. It's like the speed difference between a Ferrari and a BMW. Sure, the Ferrari can go 190mph, but you can still outrun the cops at 140mph in your BMW.

 

There is definitely a weight difference between heavier water resistant fabrics and their not-so-water resistant nylon counterparts. In an expedition bag this weight difference can be six ounces, in a summer bag it can be three ounces. Is the performance benefit worth it? It's for you to decide. There is always some tradeoff when you save weight. In many years of stuffing and unstuffing sleeping bags, I have observed no appreciable difference in the compressibility of an Event bag versus a nylon bag. This is a myth. Just yesterday I had no difficulty compressing a nylon bag and an Event bag into the same stuff sack to demonstrate this point to a skeptical customer.

 

I don't think there is some objective superiority of one sleep system or insulation over another, just different pros and cons. It's like ice tools. Everyone finds something that works for them and suits their style of climbing and hopefully can focus more on the climbing than on their gear.

 

 

 

[Jedi]

 

One difference between synthetic fiber insulation and down that many people don't realize is that down is much more breathable. This is one reason why a zero degree down bag is more comfortable on a +40 night than a zero degree synthetic bag. More breathability means better ability to transport moisture out of the insulation. A slightly, or even moderately, down bag is easy to dry out, even in wet conditions. The catch is that there is a tipping point past which, if you get your down TOO wet, it is hard to recover from. Getting your bag this wet, however, is pretty hard to do and is usually the result of an unforeseen catastrophe or incompetent gear management.

 

 

Sure, for an open bivy, Epic, Event and the like works great. But those material do not breathe as well as LESS waterproof materials. The more breathable shells are also lighter and compactable.

The problem is moisture given off by your body that ends up in the insulation. From the inside out.

So you want that moisture to pass as easily as possible, right?

 

Correct. Epic and Event work great for an open bivy, but their benefits are equally valuable on long trips in a tent where prolonged exposure to condensation can be a problem. Another problem is cold conditions where water vapor freezes to the tent walls and creates an indoor blizzard. It's true that neither Epic nor Event breathe as well as untreated taffeta nylon, but just because they are less breathable doesn't mean that these fabrics are not breathable enough. Have you ever slept in an Epic or Event shelled bag for a few nights? The breathability of these fabrics is pretty darn good. It's like the speed difference between a Ferrari and a BMW. Sure, the Ferrari can go 190mph, but you can still outrun the cops at 140mph in your BMW.

 

There is definitely a weight difference between heavier water resistant fabrics and their not-so-water resistant nylon counterparts. In an expedition bag this weight difference can be six ounces, in a summer bag it can be three ounces. Is the performance benefit worth it? It's for you to decide. There is always some tradeoff when you save weight. In many years of stuffing and unstuffing sleeping bags, I have observed no appreciable difference in the compressibility of an Event bag versus a nylon bag. This is a myth. Just yesterday I had no difficulty compressing a nylon bag and an Event bag into the same stuff sack to demonstrate this point to a skeptical customer.

 

I don't think there is some objective superiority of one sleep system or insulation over another, just different pros and cons. It's like ice tools. Everyone finds something that works for them and suits their style of climbing and hopefully can focus more on the climbing than on their gear.

 

 

 

 

I had never heard that synthetic was less breathable. Cool info.

 

That is true about cars. I use to out run the police in my 145 hp eagle Talon. it's all about the driver (back when I was still immature) hehehe

ummm back to the topic.... I wish my SnowBunting had an Event or Epic shell instead of Dryloft. Yes, there seem to be little tradeoffs and you have to pick your poison.

I have a Marmot Lithium bag that breaths quite well. It is nearly see-through. I can see some of the damp feathers stuck to the shell of the bag in the morning (no, I don't breath in my bag).

One things about it, you can't beat the compressiblity and weight of down.

 

One thing about a double bag is it is not as warm. Reason being is that you can't "seal" you bodies up in it like a classic mummy bag. The mummy is all about trapping your warm air around yourself. So, you do not develop the heat (outward force that drives moisture out of insulation). The same thing that makes breathable shell work, right? So would the down dry in a bag like this? If not, then not synthetic insulation either. So which one is better damp?

 

If you are looking at using a double bag, it probably will not be used more than a couple nights in a row so down sounds a good way to go. Unless you get stuck in a snow cave.

Diclaimer, I have not used a double bag. My ramblings, theories and jibberith come from experience with mummies. Hope to use a double bag made with down this weekend.

 

Jedi

owner of a few Feathered Friends products

 

 

Edited January 17, 2007 by Jedi