Expanding your sleeping bag's range : bag liner or over bag which is better ?

Kevin_t

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It all depends on what you are trying to achieve. I have used two quilts , one inside the other, to below 0 on a good pad.

You can also do the Nalgene bottle trick , which will create a lot of heat for a couple hours.


Synthetic , over down, in long term below freezing can offer some technical benefits. However, most of it is likely more theoretical, and quality of items matters a lot. A liner, keeps you bag cleaner , and can be a bit of a vapor barrier if desired.
 
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Grassymike

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So I have been continuing my research on options for my sleep system. I have been reading up on manufacturers websites on how they construct down bags. On the Western mountaineering site they specifically say that they make their 3 season bags with continuous baffles so down can be shifted for cooler or warmer nights. How many of you guys do this ?
 

fatlander

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So I have been continuing my research on options for my sleep system. I have been reading up on manufacturers websites on how they construct down bags. On the Western mountaineering site they specifically say that they make their 3 season bags with continuous baffles so down can be shifted for cooler or warmer nights. How many of you guys do this ?

Open the bag all the way up, grab the underside at the zipper, give it a shake if you to move down to the top. Do the reverse if you’re hot.


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long hunter

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I have used two mil. issue poncho liners tie them together and place in bag, Think bag in the bag, light weight, reasonable price and keeps me comfortable.
 

B_Reynolds_AK

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What Kevin T of Seek Outside says about layering a synthetic bag/quilt over a down one is very true. However it is not just theoretical. It absolutely works 100%.

In below freezing temps, you will get moisture building up on the outside of your sleeping bag from perspiration. If this is a down bag, the bag will most certainly start to degrade in performance as the days go on, unless you are able to dry it completely every day. By using a synthetic over down layering system, you not only bump up the temperature rating of the main bag, but also you create a temperature gradient that transfers the moisture onwards from the down bag, where it condenses on the outside of the synthetic bag.
I literally used this technique last night while on a hunt in Prince William Sound here in Alaska.
Temps were in the high 20's with zero wind and high humidity.

My Feathered Friends Tanager 20* bag was absolutely dry, while the Nunatak Graupel Apex Synthetic 50* bag that was layered over the top, was absolutely soaking. If I had just been using the FF down bag, it would have been very wet. I would very much recommend going this route for any cold weather camping. The only other way to mitigate the loss of warmth and performance from a down bag would be to use a vapor barrier liner. The option I use is much more comfortable and also gives the added benefit of protection from outside moisture as well.
 
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Grassymike

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So I purchased a new to me sleeping bag today. Found a feathered friends Lark 10 YF on the auction site. I hope it is a real good bag for what I need. Now time to decide on a sleeping pad, hopefully as a Christmas present.
 

AZ_Hunter_2000

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Here's formula when combining items:
x -(70 – y)/2 = z

x = first bag (higher rated/lower degree)
y = second bag (lower rated/higher degree)
z = rating of doubled bags

---
Use a quality bag. Use a higher R-value sleeping pad. Sleep with a base layer (ex: Peloton 97 top and bottom). Sleep with a beanie. Seal up the bag properly.

I have inadvertently taken my WM MegaLite to ~20-21 many times on multiple hunts and was not cold by doing the above. The weather guessers said the lows would be 20+ degrees warmer than reality. If they were more accurate on their predictions, I'd have brought my WM Antelope.

I have no qualms about having to push the limits on a bag for something unforeseen. However, to make it SOP is foolish because at some point Mother Nature will let you know she is there.
 

AZ_Hunter_2000

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What Kevin T of Seek Outside says about layering a synthetic bag/quilt over a down one is very true. However it is not just theoretical. It absolutely works 100%.

In below freezing temps, you will get moisture building up on the outside of your sleeping bag from perspiration. If this is a down bag, the bag will most certainly start to degrade in performance as the days go on, unless you are able to dry it completely every day. By using a synthetic over down layering system, you not only bump up the temperature rating of the main bag, but also you create a temperature gradient that transfers the moisture onwards from the down bag, where it condenses on the outside of the synthetic bag.
I literally used this technique last night while on a hunt in Prince William Sound here in Alaska.
Temps were in the high 20's with zero wind and high humidity.

My Feathered Friends Tanager 20* bag was absolutely dry, while the Nunatak Graupel Apex Synthetic 50* bag that was layered over the top, was absolutely soaking. If I had just been using the FF down bag, it would have been very wet. I would very much recommend going this route for any cold weather camping. The only other way to mitigate the loss of warmth and performance from a down bag would be to use a vapor barrier liner. The option I use is much more comfortable and also gives the added benefit of protection from outside moisture as well.
Not all down bags are equal.

Had a POS down bag that would "trap" moisture no matter the temperature. I froze in that damn bag and it did not matter it if was 30 degrees or if it was 60 degrees. That SOB led me to buying a WM Antelope which led to buying a WM MegLight. Massive difference in quality under all conditions.

Zero issues with my WM bags with moisture. Over 30 nights last year (WM MegaLight) in daily (multi-hour thunderstorms 1+ times every day), in a hammock, continuous humidity higher than Kodiak, and the bag never wetted out. Hell the foot box got exposed (see post from last year) and the SOB was dry in the AM which was never supposed to happen based upon the gloom and doom that gets tossed around. About 30 days in the field in AK on my WM Antelope with all of its "balmy" weather and never had an issue with the bag wetting out.

But that is just my personal experience.
 

B_Reynolds_AK

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So I purchased a new to me sleeping bag today. Found a feathered friends Lark 10 YF on the auction site. I hope it is a real good bag for what I need. Now time to decide on a sleeping pad, hopefully as a Christmas present.
Thats a fantastic bag. Good choice. Feathered Friends & Western Mountaineering are top tier.
 

B_Reynolds_AK

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Not all down bags are equal.

Had a POS down bag that would "trap" moisture no matter the temperature. I froze in that damn bag and it did not matter it if was 30 degrees or if it was 60 degrees. That SOB led me to buying a WM Antelope which led to buying a WM MegLight. Massive difference in quality under all conditions.

Zero issues with my WM bags with moisture. Over 30 nights last year (WM MegaLight) in daily (multi-hour thunderstorms 1+ times every day), in a hammock, continuous humidity higher than Kodiak, and the bag never wetted out. Hell the foot box got exposed (see post from last year) and the SOB was dry in the AM which was never supposed to happen based upon the gloom and doom that gets tossed around. About 30 days in the field in AK on my WM Antelope with all of its "balmy" weather and never had an issue with the bag wetting out.

But that is just my personal experience.
WM are most certainly the best you can do, along with FF. However it doesn't make the technique described unnecessary in certain conditions or expand a sleeping bags range as the OP's question was concerning.
 

JohnB

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What Kevin T of Seek Outside says about layering a synthetic bag/quilt over a down one is very true. However it is not just theoretical. It absolutely works 100%.

In below freezing temps, you will get moisture building up on the outside of your sleeping bag from perspiration. If this is a down bag, the bag will most certainly start to degrade in performance as the days go on, unless you are able to dry it completely every day. By using a synthetic over down layering system, you not only bump up the temperature rating of the main bag, but also you create a temperature gradient that transfers the moisture onwards from the down bag, where it condenses on the outside of the synthetic bag.
I literally used this technique last night while on a hunt in Prince William Sound here in Alaska.
Temps were in the high 20's with zero wind and high humidity.

My Feathered Friends Tanager 20* bag was absolutely dry, while the Nunatak Graupel Apex Synthetic 50* bag that was layered over the top, was absolutely soaking. If I had just been using the FF down bag, it would have been very wet. I would very much recommend going this route for any cold weather camping. The only other way to mitigate the loss of warmth and performance from a down bag would be to use a vapor barrier liner. The option I use is much more comfortable and also gives the added benefit of protection from outside moisture as well.

If you had make a guess how much colder do you think the 50 degree quilt let's you push your 20 degree bag? I've kinda wanted a quilt for summers and also a warmer bag for late season hunting so the concept of doing both as well as taking advantage of some of the Black Friday sales has my interest piqued.

Edit: I'm 6'2" and currently have a long Mountain Hardware Phantom 15 degree bag that I feel good in down to about 20 wearing most of my clothes on a Xtherm. Is it reasonable to assume that a 40 degree long/wide EE quilt would give me another 15 degrees or so?

Edit2: Well I answered my own question. Enlightened Equipment says it'll add 30 degrees which seems a bit optimistic. https://support.enlightenedequipmen...0588-How-to-layer-quilts-for-sub-zero-camping
 
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B_Reynolds_AK

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If you had make a guess how much colder do you think the 50 degree quilt let's you push your 20 degree bag? I've kinda wanted a quilt for summers and also a warmer bag for late season hunting so the concept of doing both as well as taking advantage of some of the Black Friday sales has my interest piqued.

Edit: I'm 6'2" and currently have a long Mountain Hardware Phantom 15 degree bag that I feel good in down to about 20 wearing most of my clothes on a Xtherm. Is it reasonable to assume that a 40 degree long/wide EE quilt would give me another 15 degrees or so?

Edit2: Well I answered my own question. Enlightened Equipment says it'll add 30 degrees which seems a bit optimistic. https://support.enlightenedequipmen...0588-How-to-layer-quilts-for-sub-zero-camping

If you had make a guess how much colder do you think the 50 degree quilt let's you push your 20 degree bag? I've kinda wanted a quilt for summers and also a warmer bag for late season hunting so the concept of doing both as well as taking advantage of some of the Black Friday sales has my interest piqued.

Edit: I'm 6'2" and currently have a long Mountain Hardware Phantom 15 degree bag that I feel good in down to about 20 wearing most of my clothes on a Xtherm. Is it reasonable to assume that a 40 degree long/wide EE quilt would give me another 15 degrees or so?

Edit2: Well I answered my own question. Enlightened Equipment says it'll add 30 degrees which seems a bit optimistic. https://support.enlightenedequipmen...0588-How-to-layer-quilts-for-sub-zero-camping

I’m not sure I would be able to give an exact rating. I think it would depend on numerous factors like AZ-Hunter stated. There are some good blog posts about this if you do some searching online. Ryan Jordan from Backpackinglight has some good insights into layering. Try a search with his name and quilt layering.

I haven’t pushed my setup to its limits yet. I may try some experimenting this winter. If it’s well below freezing, I’m most likely using more insulated clothing as part of the system too.
My Tanager is rated for 20. With the 50 degree overbag, I’d personally be fine taking it down to 10f.
I think your 15 degree improvement would be reasonable.


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AZ_Hunter_2000

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If you had make a guess how much colder do you think the 50 degree quilt let's you push your 20 degree bag? I've kinda wanted a quilt for summers and also a warmer bag for late season hunting so the concept of doing both as well as taking advantage of some of the Black Friday sales has my interest piqued.

Edit: I'm 6'2" and currently have a long Mountain Hardware Phantom 15 degree bag that I feel good in down to about 20 wearing most of my clothes on a Xtherm. Is it reasonable to assume that a 40 degree long/wide EE quilt would give me another 15 degrees or so?

Edit2: Well I answered my own question. Enlightened Equipment says it'll add 30 degrees which seems a bit optimistic. https://support.enlightenedequipmen...0588-How-to-layer-quilts-for-sub-zero-camping
That is for T Limit which they point out. Reality should be closer to 5*. The math: 20-(70-40)/2=5.

Actual results will depend on gear, gear condition, sleeper, etc but you get the gist.
 

HeavyAssault

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I didn't really see it covered so I'll just speak for my experiences.
1) Get off the ground, meaning the least amount of direct ground contact possible. Air mattress or just use the area foliage to build a bed. Something like 2-3" stacked will crush down overnight but then you can reconstitute the area day-to-day.
2) Windproof layer: Think something like a Gore-Tex bivy sac. It can be a double edged sword so you just need to see what works for you. You are sealing yourself inside a bag...just use something that breathes well but protects from air getting in.
3) Sleeping bag rated "right at" or just over expected outside temps. Don't buy a 20*F bag for 40*F outside temps. You will end up using layers to make your 40*F bag comfortable to 20*F outside temps.
4) Decide what layers of clothes work for you. Merino wool or of the such types tend to work great next to the skin, Any other clothing can be lined inside the bag....no real need to wear them. Don't forget you will be sweating while sleeping. Not like a 20 mile run but your body/skin is going to sweat.
5) Extra sleeping bag or bivey sac liners: As above they can be squeezed down to small sizes compared to crushing your sleeping bag. Lining the bag/bivey inside or even outside help build that air space that the body will warm.

I found that all those wonderfully thick wolly bully things were not helping me. Thinner layers worked best on my body. Then the concept extended to the sleeping system. Yes, I might end up with more items by shear numbers but they worked best with multiple combinations or configurations. You can always leave stuff in a pack that you don't use while sleeping, but you can't add stuff to your pack once you are in the wood line.
 

sneaky

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If you had make a guess how much colder do you think the 50 degree quilt let's you push your 20 degree bag? I've kinda wanted a quilt for summers and also a warmer bag for late season hunting so the concept of doing both as well as taking advantage of some of the Black Friday sales has my interest piqued.

Edit: I'm 6'2" and currently have a long Mountain Hardware Phantom 15 degree bag that I feel good in down to about 20 wearing most of my clothes on a Xtherm. Is it reasonable to assume that a 40 degree long/wide EE quilt would give me another 15 degrees or so?

Edit2: Well I answered my own question. Enlightened Equipment says it'll add 30 degrees which seems a bit optimistic. https://support.enlightenedequipmen...0588-How-to-layer-quilts-for-sub-zero-camping
The formula for figuring it out was posted in this thread a few replies above your question
 

MattB

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WM user, I’ve founds that from unzipping the side of the bag/draping an arm out to zipping it up fully and drawing down the hood closure to the smallest degree you can stand it can make a bag comfortable over a 15-20 degree range. No need for more stuff although I acknowledge some guys can’t sleep with only a softball-sized opening for your mouth.

Add a beanie and thermals to give you even more warmth.
 

gabenzeke

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I have a bag liner that I use with my quilt. But I don't know that it increases warmth all that much. I mostly use it to help with drafts if my taro is set wrong for the wind. And then it only helps a little.

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BBob

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I acknowledge some guys can’t sleep with only a softball-sized opening for your mouth.

Add a beanie and thermals to give you even more warmth.
That’s me. I’ve never really been able to use a hood and really dislike draft collars. I can’t even pull the upper drawstring on quilts or hoodless bags very tight without it bothering me and tend to clutch them closed with a hand when it gets cold. Claustrophobia can be a bitch 😀

In addition to a beanie and because of the above I’ll drape a shirt or a puffy partially over my head and shoulders when the temps start pushing my bag limits.
 
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E6ylK

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Others have said this, but if using both synthetic and down, the synthetic should be on the outside (when practical), due to condensation.

Don’t discount the importance of a sleeping pad with a high r value in cold weather. I’ve found this to make a huge difference in warmth and would rather a marginal bag with a blanket (woobie, cheap down, etc) and good pad, vs a great bag on a low r value pad.

I’d look for a minimum of ~5 r value ASTM for cold weather (winter, snow, etc). Also, r values are additive, so two pads of 3 and 2 equal 5 total.
 
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