Fleece bag liner for extra confort or not!

[Dazzy001]

Newbe to hiking; Is there any value in the extra weight of a sleeping bag fleece liner, would i be better of just getting a AMK Thermo-Lite 2 Bivvy Sack to add extra comfort to my North Face 0 deg sleeping bag. for cold and/or wet nights.

Darren

[take-a-knee]

What is an AMK theromlite bivy? Is this an overbag?

[scope]

I assume this is a lightly insulated (thermolite) bag with a more substantial exterior shell to be called a bivy. Probably fuller cut to be used as an overbag, which is something I prefer to an interior liner.

The overbag is going to be more comfortable/warm for cold/wet, but there is a risk of interior condensation if the bivy doesn't breathe well. Sounds like it might be useful as a summer bag as well.

To me, the liner benefit would be lower weight - you've got a zero degree bag so you don't need much extra - and it will help keep your NF bag cleaner (less funky) if you're out for extended periods.

[awestberry]

Cheap solution - buy two lightweight fleece blankets and sew the two long sides and one short side together to make a liner. I made one last winter and have loved it. Total cost was $6 - blankets were $3 each on clearance and I already had the thread. Only downside is that it is baby blue.......

[Dazzy001]

Here is a like for the Thermolite bag: http://www.alpineer.com/istar.asp?a=6&id=118102!lib01.

[Dazzy001]

I thought about that too, Its just that the new Black Diamond Lightsabre Bivy Sack is not completly waterproof, thus i don't want to get cought out in bad weather and frezze my nuts off all night. I thought this might add a eliment of warmth and comfort unlike just adding a fleece insert. As it is supost to be robust enoth to withstand a down poor.

[take-a-knee]

Here is a like for the Thermolite bag: http://www.alpineer.com/istar.asp?a=6&id=118102!lib01.

Most definetely not a good idea. It is waterproof, the outside of your bag would be soaked in the morning. I have an old patagonia thermolite overbag that works well but it is just insulation and nylon, it breathes.

[Dazzy001]

Forgive me for being simple, but i was thinking of putting this over the top of me NF sleeping bag, It has a fleece liner inside of it, why would my bag would be soaked in the morning??????

Sorry for being an silly!

[scope]

Forgive me for being simple, but i was thinking of putting this over the top of me NF sleeping bag, It has a fleece liner inside of it, why would my bag would be soaked in the morning??????

Sorry for being an silly!

Condensation.

In your setup, you're not allowing your bag to efficiently get your body heat, so you might actually be colder with this thing on the inside.

Your zero degree bag ought to be good enough on its own for down to the teens. A cheap summer bag would do nicely for an overbag for temps below that.

[canerunner]

Here is a like for the Thermolite bag: http://www.alpineer.com/istar.asp?a=6&id=118102!lib01.

DO NOT use this as an overbag or bivy. I use one fo these as my emergency "space blanket", and it's not breathable. It will soak your sleeping bag. I have used mine inside my sleeping bag when I got into a situation where my bag wasn't warm enough, but never on the outside of my bag.

This Thermolite will keep you from freezing to death if used right, or it could cause you to freeze to death if not used right.

I carry a liner, and it will extend the temperature rating of your sleeping bag, but not that one. The one I have is the Sea to Summit Reactor Thermolite. It's a breathable fleece like material that I find very comfortable to sleep in.

[take-a-knee]

Forgive me for being simple, but i was thinking of putting this over the top of me NF sleeping bag, It has a fleece liner inside of it, why would my bag would be soaked in the morning??????

Sorry for being an silly!

Don't take this the wrong way dude, if you don't understand the concept of insensible perspiration, convection, conduction and the like, you really need to read up on it before you get out in the woods and become a statistic.

[tlw08]

So please confirm for me, a simple SPACE emergency bag will function properly within a sleeping bag and add some degree of warmth to an evening's sleep, yes?

[Appalachian Tater]

I wouldn't waste the weight or space for a fleece liner. A silk liner, yes. Better even would be long underwear, socks, hat, made of wool or some other heat-conserving material.

[saimyoji]

Dazzy,

I recommend you go on some practice campouts. No need for long hikes, sleep out in your back yard and test your sleeping comfort range. You may find that that 0* bag is more than enough to keep you comfy in conditions you'll encounter out in the woods.

I myself sleep out in the backyard 2-3 times a week.

[scope]

So please confirm for me, a simple SPACE emergency bag will function properly within a sleeping bag and add some degree of warmth to an evening's sleep, yes?

Essentially the answer is probably Yes to "some degree of warmth". However, the radiant heat comes from your body and is reflected by the blanket back to you. That means your sleeping bag is not going to receive as much of your body heat to warm it up, and thus it will stay cooler.

These things are meant for lightweight emergency uses and not as a liner or overbag. You ever slept on a bed that had a waterproof pad on it? (I have a toddler in toilet training, so I'm experienced in this matter ) Your body moisture gets trapped under you so that you wake up wet like you've been sweating.

Fabric liners offer a bit of warmth and comfort while still radiating the heat to your bag and allowing moisture to evaporate. Personally, I use my summer bag over my 20 degree bag when I think I need it. I've also slept with a bivy over my bag and achieved about the same warmth.

[take-a-knee]

So please confirm for me, a simple SPACE emergency bag will function properly within a sleeping bag and add some degree of warmth to an evening's sleep, yes?

It will function as a vapor barrier of sorts, your insensible persiration would create a moist damp environment between your skin and the space blanket, any clothing you were wearing would be damp in the morning. It wouldn't be very pleasant. A full vapor barrier liner works but you can't wear a lot of clothing or it'll get pretty wet. Just wrapping up into a blanket inside of a bag would dump some moisture into the bag, not a good idea.

In a survival situation where you would normally use a space/emergency blanket, you would be so cold your sweating response would be minimal or non-existent. You also would not be sleeping long enough (if you slept at all) for a lot of moisture to collect inside the blanket.

[take-a-knee]

I wouldn't waste the weight or space for a fleece liner. A silk liner, yes. Better even would be long underwear, socks, hat, made of wool or some other heat-conserving material.

I agree, mulituse equals lighter pack. I think the main advantage of a liner would be keeping the bag clean on a long hike, thereby preserving it's loft.

[Dazzy001]

I clearly understand now, It all make sense now, i will get a silk bag liner and ditch my original idea...... Thanks to all.

Darren

[Tinker]

Hey, Darren.
I'd just like to add my two cents. I think you'd get the most use of the weight on your back if you wear long underwear in your bag, or even fleece pants and jacket or pullover instead of a liner.
The point is that the liner is just that - a liner. Not much use for anything else, yet you have to carry it all day and only be able to use it at night (and only in your bag).
An extra set of oversized long underwear to wear over your regular size would keep your bag clean and keep you warm when you go looking for a tree in the night.

[Dazzy001]

That's a great suggestion i will look into that.