Sleeping Bag Cover

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DayTrip

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Sort of a derivative question to my shelter question: is there such a thing as a sleeping bag cover? And by cover I don't mean a standalone bivy sack type thing. I have one of those. I have a 20 deg sleeping bag which is not going to cut it for real Winter nights and I'm not sure I'll be able to afford an upgrade this season. So I'm looking more for something that would provide some basic protection against condensation (not bullet proof waterproofing) in the tent getting on my sleeping bag and provide some added warmth to my existing bag. These items also seem to help with keeping yourself on your sleeping pad because it fits inside the sack, which would be an added plus.

Seems like a murky topic on posts I've read. Sounds like the closer you get to a true bivy the more you increase the chances of internal condensation in the bag from lack of breathability. The MSR E-Bivy seems like the kind of product I might be interested in. If anyone has tried a product of this sort and can shed some light on whether or not it is worth the money I'd appreciate the feedback. I have one of those inner sleeping bag liners but it doesn't seem to provide much of a boost in warmth (although I haven't really had much experience with it to this point).
 
I use a removable silk liner in my sleeping bag, it was advertised, and I believe it adds 10F degrees of comfort, as well as keeping my bag clean. In even colder conditions, if I do want to carry a heavier bag, I also have a home made flannel inner bag that works well. As a third option, i also made a fleece liner bag, but it is a bit heavier. Sometimes during warmer nights I might use each liner just by itself for an added option.
 
A bivy or cover will only give you maybe another 5 to 10 degrees of comfort or so, is that worth $100? Not knowing what you use for a pad, you might be better off spending that money on a z-light under you and just wearing more. I use to do some pretty dumb stuff with my 20* set but was able to get down to around 0* comfortably by using a space blanket, hot water bottles, and considering none of my clothing as "extra."
 
A bivy or cover will only give you maybe another 5 to 10 degrees of comfort or so, is that worth $100? Not knowing what you use for a pad, you might be better off spending that money on a z-light under you and just wearing more. I use to do some pretty dumb stuff with my 20* set but was able to get down to around 0* comfortably by using a space blanket, hot water bottles, and considering none of my clothing as "extra."

I have a pretty good pad. It is the Big Agnes Quad Core something or other. Think it has an R value of 4.0 or thereabouts. And no, I really didn't want to spend $100 on an item like that unless there was pretty good feedback out there that it was worth it. I have a Gore Tex shelter bivy that is too heavy and cumbersome for this application (I carry it as an emergency shelter on Winter day hikes) but when I've tried it out to see how it works it was surprisingly warm so I wondered if something comparable might have a similar impact.
 
Sometimes during warmer nights I might use each liner just by itself for an added option.

I noticed that. This past Summer on my Baxter trip it was super hot at night. I was actually sleeping on top of my sleeping bag on the liner I had. As it cooled down a bit I would just get into the liner and it provided the perfect amount of warmth. Not the intended use I had bought it for but it worked out pretty well.
 
Couple of comments:

1. I am assuming you already would be bringing the following preliminarily for sleeping only [and as emergency layers back-up]: mid-weight wool underwear tops and bottom, plush warm socks, wool or fleece liner gloves, fleece vest, and wool or fleece toque - this kit adds a ton of range and flexibility to my sleep system

2. I have a silk liner that keeps the winter bag clean but I don't think it adds noticeable warmth

3. I had great, great success with a down 15 deg F mummy [MARMOT SAWTOOTH] inside a syn 15 deg F semi-mummy [BA ENCAMPMENT]. A very bulky solution but worked extremely well because the inner bag was able to loft inside the outer bag

4. Hoping this isn't as polarizing as discussing religion and politics but....IMO the closed cell foam pad should be top of the air pad for best results; not vice versa

5. If I bought a bag cover to be able to sleep directly on the snow, I would want the top half to be eVent material.
 
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You may be looking for an overbag. A over-sized sleeping bag that will fit over your existing sleeping bag with out compressing it. They typically add insulation with out weatherproofing. A couple of options are the TNF Ocelot or the Big Agnes Cross Mountain or Yampa bags. These bags are rated for around 40 degrees alone and for 15 to 25 degrees when used an overbag. Wiggley's also make a sleeping system that includes layering of bags. The synthetic vs down argument that exists for sleeping bag also exists for overbags.

Other options include an expander which zips into a sleeping bag to increase the width or girth of the bag. Then use the widen bag as the overbag. I think Big Agnes and Western Mountain have expanders. Or using a Thermarest or anther manufactures quilt that fits around your sleeping pad as an overbag. I use a MH Down Upgrade that zips in to my sleeping bag as a liner and it also increases the width of the sleeping bag. It is rated at 40 degrees alone and adding 25 degrees when used as a liner.
 
Couple of comments:
1. I am assuming you already would be bringing the following preliminarily for sleeping only [and as emergency layers back-up]: mid-weight wool underwear tops and bottom, plush warm socks, wool or fleece liner gloves, fleece vest, and wool or fleece toque - this kit adds a ton of range and flexibility to my sleep system

Yet another stupid question but I'll ask it anyway: do people actually strip down to their birthday suit in the depths of a frigid Winter night to put on sleeping clothes and then swap back into their hiking clothes in the morning? Seems like a bad idea both loosing all the built up heat you have changing in and out of your sleeping stuff and then putting on frigid clothes in the morning to start the day (I assume you stuff the dirty clothes in your sleeping bag otherwise but that doesn't seem super smart either if they are damp or wet from snow melt, sweat, etc.).

To answer your question I do have a "sleeping clothes set up" of mid weight merino wool top and bottom base layers as well as a hat and/or balaclava and socks with me generally. This adds a lot of weight though and is redundant for me at least in Winter because I'm probably wearing similar layers already (I get much colder than average based on what others say they wear hiking, in all seasons). Does your thought process change at all on a single overnight versus a multi day trip?
 
What about a vapor barrier sack like this one from Western Mountaineering: https://www.backcountry.com/western-mountaineering-hotsac-vapor-barrier-liner?skid=WES000W-ONECOL-ONESIZ&ti=UExQIENhdDpTbGVlcGluZyBCYWcgTGluZXJzOjE6MjQ6YmMtc2xlZXBpbmctYmFnLWxpbmVycw== I presume this really is for long trips. I have read articles about sleeping bags slowly absorbing moisture on huge expeditions to the point where they become absurdly heavy. Wouldn't really apply in my situation. I do use vapor barrier socks often though and they work well so why not the whole body??

And if an over bag is just a warm weather bag maybe I'm ignoring the obvious: I have a pretty light 50 deg Marmot Nano sleeping bag for warm weather. Could I simply use that as my liner? Does combining multiple bags compress the fill and actually makes things worse? (I think my Nano bag would easily fit in my 20 deg bag so I assume no).
 
Yet another stupid question but I'll ask it anyway: do people actually strip down to their birthday suit in the depths of a frigid Winter night to put on sleeping clothes and then swap back into their hiking clothes in the morning? Seems like a bad idea both loosing all the built up heat you have changing in and out of your sleeping stuff and then putting on frigid clothes in the morning to start the day (I assume you stuff the dirty clothes in your sleeping bag otherwise but that doesn't seem super smart either if they are damp or wet from snow melt, sweat, etc.).

To answer your question I do have a "sleeping clothes set up" of mid weight merino wool top and bottom base layers as well as a hat and/or balaclava and socks with me generally. This adds a lot of weight though and is redundant for me at least in Winter because I'm probably wearing similar layers already (I get much colder than average based on what others say they wear hiking, in all seasons). Does your thought process change at all on a single overnight versus a multi day trip?

Sometimes I do, sometimes I don't. Depends on how wet my clothes are and what temps I'm expecting. I wear a lightweight layer for hiking and carry a heavyweight for sleeping/layering. I'll wear my lightweight layer for as long as possible at camp to dry them before changing into or adding the heavyweight set. The cold of changing is a nice motivation to get moving in the morning.
 
Yet another stupid question but I'll ask it anyway: do people actually strip down to their birthday suit in the depths of a frigid Winter night to put on sleeping clothes and then swap back into their hiking clothes in the morning? Seems like a bad idea both loosing all the built up heat you have changing in and out of your sleeping stuff and then putting on frigid clothes in the morning to start the day (I assume you stuff the dirty clothes in your sleeping bag otherwise but that doesn't seem super smart either if they are damp or wet from snow melt, sweat, etc.).

To answer your question I do have a "sleeping clothes set up" of mid weight merino wool top and bottom base layers as well as a hat and/or balaclava and socks with me generally. This adds a lot of weight though and is redundant for me at least in Winter because I'm probably wearing similar layers already (I get much colder than average based on what others say they wear hiking, in all seasons). Does your thought process change at all on a single overnight versus a multi day trip?

Depends. I've worn the same clothes straight through, and also changed. Mostly depends on how tired I am. I am a warm sleeper, so I've also been known to strip down to skivvies when sleeping. And, no, it's not easy to get out of the the bag like that but boy, it does get you going in the morning once you do.

Most occasions, I am in lightweight LJs an a shirt, and socks. If my other clothes are wet, I slip them between my closed-cell and Therm-a-rest pads and they will normally dry overnight.
 
If my other clothes are wet, I slip them between my closed-cell and Therm-a-rest pads and they will normally dry overnight.

Might be creating drift in my own thread but is it necessary to have two pads in Winter? If you have a good insulated inflatable does the closed cell pad matter? That does seem like a good idea sandwiching the wet clothes in their though. Will have to remember that tip.
 
Might be creating drift in my own thread but is it necessary to have two pads in Winter? If you have a good insulated inflatable does the closed cell pad matter? That does seem like a good idea sandwiching the wet clothes in their though. Will have to remember that tip.

I cut the ridge-rest into a 1/3 and 2/3 piece. The 1/3 piece goes everywhere with me. It's a seat on a cold rock, something to stand on, goes inside my pack to protect anything from poking me, dayhikes, working in the yard, stadium seat. etc. The 2/3 piece is a bench insulator for my custom-built kitchen that's dug into the snow. At night, lay them both out under the Therm-a-rest as they are warmer (T/R's can sometimes be colder as there is air in there). It also helps to have an extra layer of insulation in the snow as you move about inside the tent.
 
Yet another stupid question but I'll ask it anyway: do people actually strip down to their birthday suit in the depths of a frigid Winter night to put on sleeping clothes and then swap back into their hiking clothes in the morning? Seems like a bad idea both loosing all the built up heat you have changing in and out of your sleeping stuff and then putting on frigid clothes in the morning to start the day (I assume you stuff the dirty clothes in your sleeping bag otherwise but that doesn't seem super smart either if they are damp or wet from snow melt, sweat, etc.).

To answer your question I do have a "sleeping clothes set up" of mid weight merino wool top and bottom base layers as well as a hat and/or balaclava and socks with me generally. This adds a lot of weight though and is redundant for me at least in Winter because I'm probably wearing similar layers already (I get much colder than average based on what others say they wear hiking, in all seasons). Does your thought process change at all on a single overnight versus a multi day trip?

I do change out in my tent. A couple of jumping jacks after, or processing some wood after, is all it takes for me to warm back up. The temporary cold can be very focusing. We aren't talking "To Build a Fire" temperatures here; I have never camped out in temps that are causing the trees to crack. I aborted a chance to camp out in -20 F a number of years ago & the opportunity hasn't presented itself again.

In the winter, I hike the valley trails with a pulk and ZEALOUSLY try to avoid sweating into my base layers; I have no problem hiking very slowly since I have no fixed destination except "deeper into the woods" :). I only occasional hit a summit from a base camp but it would have to be a bluebird day.

The only difference for me on multi-night trips is that I push all the warm air out of my sleeping bag immediately after I get out of it and, if camped in a sunny spot, I hang the bag in the sun in an attempt to sublimate any frost in the bag (but no idea if that really does anything worthwhile).
 
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And if an over bag is just a warm weather bag maybe I'm ignoring the obvious: I have a pretty light 50 deg Marmot Nano sleeping bag for warm weather. Could I simply use that as my liner? Does combining multiple bags compress the fill and actually makes things worse? (I think my Nano bag would easily fit in my 20 deg bag so I assume no).

That seems to be an option you could try and then tell us how it works out. Personally, I think adding a down 50 deg. bag inside a synthetic 20 deg. bag would still not be warm enough for subzero temps. My other concern would be that the down might absorb lots of perspiration while you're sleeping. You would not notice it until you wake up cold and then, how do you get warm again?
 
That seems to be an option you could try and then tell us how it works out. Personally, I think adding a down 50 deg. bag inside a synthetic 20 deg. bag would still not be warm enough for subzero temps. My other concern would be that the down might absorb lots of perspiration while you're sleeping. You would not notice it until you wake up cold and then, how do you get warm again?

A 20 and a 50 should get you to right around 0. I use the formula x-(70-y)=z when stacking. IME, the moisture pushes through the down and freezes towards the outside of the synthetic. The synth isn't going to lose much loft so it isn't really an issue unless it gets saturated. Not likely much sweating going on when you're pushing comfort levels.
 
That seems to be an option you could try and then tell us how it works out. Personally, I think adding a down 50 deg. bag inside a synthetic 20 deg. bag would still not be warm enough for subzero temps. My other concern would be that the down might absorb lots of perspiration while you're sleeping. You would not notice it until you wake up cold and then, how do you get warm again?

Both bags are synthetics. And I sleep cold. Pretty rare for me to be sweating in shoulder season/Winter season temps. So I don't think that would be a huge issue but until I try it I have no idea.
 
Both bags are synthetics. And I sleep cold. Pretty rare for me to be sweating in shoulder season/Winter season temps. So I don't think that would be a huge issue but until I try it I have no idea.

My mistake. I forgot Marmot made synthetic bags.
 
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