Using two sleeping bags for winter camping

[Shadow]

Hi All,

Quick question for this learned population. I plan on a winter trip to do Macnaughton in a few weeks, but don't have my winter bag anymore. What do you all think about using a 30 and a 40 degree together (one inside of the other)? Any recs on what should be the outside bag?

Thanks

Shadow

 

[sierra]

I used that technique when first starting out. Keep in mind that those rated bags will still fall short in holding heat as thier insulation qualities are just not there. I would guess you could go to 20 degrees or there about with those two bags. You should also consider using a sleeping pad (a must), sleeping in some clothes, ie.long underware, a hat, good socks. Bottom line, i wouldnt do it anywhere but car camping, this method would not be suited for the backcountry.

 

[DougPaul]

Double bagging can work well, but I doubt that 30F+40F is a good combination. For instance, they probably don't have hoods... At best, I suspect that you might get the equivalent of a 10F bag out of them. (10F is marginal for the WMNF--temps can get down to ~-40F.)

I have used a double bag system very effectively: a 15F down bag inside a 0F polyester bag, but it was heavy and took up a lot of space in my pack. (Polyester should be on the outside.)

This topic has been discussed before--see the prior threads:
Furthest below your bag's rating?
http://www.vftt.org/forums/showthread.php?t=8069
Sleeping bag ratings
http://www.vftt.org/forums/showthread.php?t=14481

Doug

 

[Little Rickie]

I do it all the time. A 20 mummy inside a 40 rectangle along with a double wide emergency bag if I feel cold. I'll keep doing this until I get tired of the weight or dig deep for -20 goose down.

The most I've done this for is two nights. For extended trips I would have to get a good single bag and a vapor liner bag. Most of my trips are weekends.

 

[Chugach001]

I used two 30-40f bags for years when I was starting out. They were comfortable at zero and less so at -20. But they still worked and it's a great way to save money for other things.

Good luck,

 

[dug]

Just be careful that they aren't too tight. If they get tight, you may lose your loft, and defeat the purpose.

I too have done it, a 0 mummy inside a 20 rectangular. It's not preferred method, though.

 

[Brambor]

it should work

as others have said: it will work until certain temperature and it is only up to you to figure out what it is. Just camp outside of your house overnight and you will know before you go.

Here are a few other pointers:

If you don't have a hood or a mummy bag then just dig deep into the rectangular, cinch the top by hand and only leave a bit of space for breathing.

You can of course wear a hat... and cinch the rectangular around your neck. It works.

Hot water bottle - works like a champ. Take a nalgene and fill it with boiling water. It will last 4-5 hours. I don't know how long. I'm sound asleep by then but waking up around 4 am realizing it's cold.

If it gets very very very cold (and if you don't have a pad) - lay on your belly with your hands on your privates. Not a very comfortable position but it will help elevate a lot of the body off the cold ground along with some vital organs

as a kid with no money I did a lot of winter camping in a cotton bag. brrrr. but still better than staying home.

 

[hikerfast]

i put a 20 bag inside of a 20 bag and slept out when it was maybe 10 below. it worked fine but its real bulky inside your pack and heavier. certainly doable. i like the idea of being inside a rectangular bag

 

[Chip]

Your sleeping bag (or bags) is one (slightly over-rated) component of your winter camping comfort. I have never double (sleeping) bagged, but I've been in situations where I wish I had. Plenty of pre-down-sub-zero-rated-bag campers have survived the night. There are a number of components that aid warmth. Here's a partial list:

- You, your garments, socks, underwear, bag, etc need to be BONE DRY. Don't expect to be warm if ANYTHING touching you or next to you is even reminiscent of damp. Change out everything before bed.

- Use 2 long and wide sleeping pads.

- Use a $35 breathable Sleeping Bag Cover, all the time everywhere regardless. This adds about 10 degrees to the bags rating, keeps it dry, keeps you, your bag and the pads in one place and gives you something to pull over your face and breath into during the night that isn't freakin horribly cold. It also evens out cold spots caused by your bag and by you tossing and turning.

- Eat something high in fat before sleep.

- Use a Pee-Bottle. It won't go away. As soon as it wakes you, take care of it.

- Wear a nylon or fleece balaclava, down booties or wool socks and fleece or wool gloves...as long as they're DRY.

- Sleep in a winter tent. This adds another 5 -10 degrees and is free of drafts.

I keep 2 water bottles in insulated cozzies inside the bag cover but outside the bag to keep them from freezing, but I've never been comfortable with the "hot water bottle in the bag for warmth" technique.

Take everyone's suggestions and then sleep in the yard with what you have this weekend, even if it's a summer tent, double bags, whatever. Ultimately some people sleep cold and others hot and you need actual experience to determine how you'll be comfortable.

Good Luck. WINTER CAMPING ROCKS !!!

 

[DSettahr]

If you use the hot water bottle method for added warmth, make sure you crack the bottle open just a little bit after a few minutes to allow the built up pressure to escape. Otherwise, it can leak.

 

[DougPaul]

The hot water bottle trick can give you an initially warm sleeping bag and keep you warm for a little while, but won't help after several hours. It is not a substitute for a bag that is warm enough for the conditions. (Since you have to keep water bottles inside your bag to keep them from freezing anyway, they might as well be hot...)

I always wear a heavy wool or polyester balaclava in a winter sleeping bag--not only does it reduce heat loss, it helps to keep skin and hair oils from getting into the bag.

Doug

 

[DSettahr]

Oh, and if you use a pee bottle, make sure it's larger than 1 liter. 1.5 liters minimum, 2 liters isn't a bad idea. Nalgene bottles do come in larger sizes, but you usually have to special order them.

The advantage of a bigger pee bottle is that it's easier to tell the difference in the dark between drinking water and pee, and you're less likely to have an overflow.

As for hot water bottles, I agree that they should not be relied upon as a primary source of warmth, and yeah, they do cease to give out more heat sometime during the night. One thing that I do is I keep them in their coozies when I bring them into my sleeping bags- this way, the heat is given off more gradually throughout the night.

 

[MichaelJ]

One thing that's going to chill you down is the condensation as the perspiration off your body works its way through the bag to the outermost layer. If you're too warm and sweaty you can produce enough moisture to form frost on the outside of the bag, and of course any dampness within the bag will reduce loft and conduct heat away. This is why you don't want to overdress, why a breathable sleeping bag cover is a good idea as it provides an independent surface for that moisture to wick to (or freeze on) and keep your bag nice and dry, and why you need to really use caution when using two sleeping bags that everything still breathes well enough to keep you dry.

It also means that you must do the hot water bottle trick carefully. I find that when I'm in the bag with boiled bottles, I'm often too warm. Then I fall asleep and wake up a few hours later either with frosted sweat all over the bag, or find that I pulled my arms out, unzipped, etc. and am myself now freezing. You can start out with bare bottles to pre-warm the bag before you get inside, but then definitely cozy them to reduce the heat when you get in.

 

[DougPaul]

One thing that's going to chill you down is the condensation as the perspiration off your body works its way through the bag to the outermost layer. If you're too warm and sweaty you can produce enough moisture to form frost on the outside of the bag, and of course any dampness within the bag will reduce loft and conduct heat away. This is why you don't want to overdress, why a breathable sleeping bag cover is a good idea as it provides an independent surface for that moisture to wick to (or freeze on) and keep your bag nice and dry, and why you need to really use caution when using two sleeping bags that everything still breathes well enough to keep you dry.

Actually, a cover does not protect the bag from inside moisture. It may protect against outside moisture.

Your skin is moist and always emits insensible perspiration when the adjacent humidity is less than almost 100% (which in practice only happens if you are wearing a vapor barrier layer (VBL) close to your skin). Thus moisture is always diffusing through the sleeping bag. Some of it will condense and that which condenses out beyond the frost surface will freeze. (There is a temperature gradient across the insulation--the frost surface is the surface where the temp is 32F.)

Being hot and sweaty makes the problem worse, but it still happens. The amount of moisture that collects in a bag is generally not serious for a weekend trip (1 night), but on longer trips the loft of a down bag can decrease significantly. Polyester bags are less affected by moisture and frost in the insulation.

One can keep body moisture out of a bag by using a VBL--see http://home.comcast.net/~pinnah/DirtbagPinner/vb.txt for a discussion of their use.

Doug

 

[Brambor]

not that I would advocate

not that I would advocate recommending TWO bags system but theoretically you can reverse the two bags and get one more night in a dry bag out of this

 

[Chip]

Hi All,

Quick question for this learned population. I plan on a winter trip to do Macnaughton in a few weeks, but don't have my winter bag anymore. What do you all think about using a 30 and a 40 degree together (one inside of the other)? Any recs on what should be the outside bag?

Thanks

Shadow

Looks like it's going to be about 13 friday and saturday night on LI, Shadow. Good trial temp. Colder Sunday night, but you might not want to go to work the next day if you're up half the night.

 

[DougPaul]

not that I would advocate recommending TWO bags system but theoretically you can reverse the two bags and get one more night in a dry bag out of this

Might not be such a good idea--your body heat will drive the moisture from the (new) inner bag and into the (new) outer bag. This will, of course, chill the heater (ie you). The worst place for moisture is in the inner layers of your insulation.

In an earlier post, I stated that if you mix polyester and down bags, the polyester should be on the outside. This is because the polyester bag will be less affected by the moisture/frost and the down will stay dry/drier. Polyester bags tend to be stiffer than down and more subject to pumping air in and out as one breathes. The down bag will fill the space within and greatly lessen the pumping.

Doug

 

[Craig]

One would think the weight of the outer bag would compress the inner bag cutting down on loft.

 

[DougPaul]

One would think the weight of the outer bag would compress the inner bag cutting down on loft.

I would expect to lose some loft in the combination, but the down inner was very effective in preventing pumping from the polyester outer. FWIW, the my combination was very warm--just big and heavy to carry.

Doug

 

[coldfeet]

Hey Shadow, I'm in Plainview and IndianChris is near the Nissy river (I just drive to his house, I'm bad with town names)...we are planning a short hike tomorrow in Caumsette, pm me if your interested, we are going really early, to listen for owls, don't ask what time, you would think we're crazy