Sleeping Bags, Liners and proper use.

[CamKelley]

Hey guys,

So as I'm beginning to stash gear away for the fall/winter camping season, I've begun to ponder on buying another bag. I currently have a 35F Western Mountaineering down bag, and a bulky synthetic 0deg bag. The latter is not really feasible for much travel unless I'm packing in for one or 2 days and can go light everywhere else. So in my research, I came across the Thermolite liner that claims 25 degrees extra warmth. I'm a furnace as it is, so I could probably squeeze it to max potential but regardless... most all the reviews seem to be crap. This brings me to the point...


In your experiences, how close are your bags to their temp rating? I've been in the mid 20's in my bag without issue. BUT, I also learned from my 'Nam vet scout master years ago.. sleep in skivvies and pack the rest around your feet. So, next question, how do you sleep in your bag? I think I may invest in a liner vs buying a new bag this year since moving is going to consume a ton of free finances and just buying cold weather gear in general will be a big step. Anyone have good results with a liner?


-Cam

[randalmartin]

I would be very skeptical of a liner claiming any more warmth than a few degrees. Temp ratings are pretty poor from many bag manufacturers and the combination of variation in individual comfort levels and bag ratings make it difficult to be too precise. Having said that, I believe the best choice to be a quality down quilt. They are adaptable to a range of conditions and so they work well for 3 season use. For a great value, consider the Enlightened Equipment - Revelation series of quilts

http://www.enlightenedequipment.com/revelation/" onclick="window.open(this.href);return false;

On the high end, the single best sleeping quilt for 3 season use is this bag made by Katabatic Gear, a local Colorado company.

http://katabaticgear.com/shop/palisade-sleeping-bag/" onclick="window.open(this.href);return false;

[ezabielski]

On the high end, the single best sleeping quilt for 3 season use is this bag made by Katabatic Gear, a local Colorado company.

http://katabaticgear.com/shop/palisade-sleeping-bag/" onclick="window.open(this.href);return false;

I own two Katabatic bags (Palisade and Sawatch) and they are fantastic. I used my Palisade for a PCT thru hike, and it's definitely conservatively rated vs most bags, it's warmer than probably any other 30 degree "rated" bag. Though in the OP's situation it would be a bit redundant with his 35 WM bag. The Sawatch (15F) or Alsek (22F) would be a good compromise.

[Kent McLemore]

With skivvies, my Western Mountaineering bag seems good to 20 deg. as advertised.
I tried a liner for a few trips and couldn't stand it - always felt tangled up. Plus, I don't think it added much warmth. It was a Sea to Summit model.

[Chase_Rowdy]

I have a Kelty Dualist (1/2 syn 1/2 down) , rated at 32 Degrees. I'd say its really only comfortable in +40 temps. I added an REI microfiber liner and it easily added 15 degrees of warmth without being too constricting.
I even use it even when it not cold, because it makes keeping your bag clean so much easier!

However, where I really added warmth to my sleeping system was through my sleeping pad. You really do lose a ton of heat to convection to the ground. Having a good sleeping pad with a high R rating makes a big difference!

[TallGrass]

I came across the Thermolite liner that claims 25 degrees extra warmth. ... how close are your bags to their temp rating? ... So, next question, how do you sleep in your bag?

Unless that liner is 1/2" thick, I'd say it's bunk, or based on a highly unrealistic in-house "experiment" like taking two microwaved potatoes, wrapping one, then setting them both outside for 5 min.

Too many variables, and countless more opinions, for the second. Besides different makes, models, shapes, and lofts of bags, people have different body fat (insulation), height, weight, skin surface area, metabolic rate (heat production), diet (fuel), circulation (cold feet?), and camp on different surfaces (rock, leaves, snow, pine needles, foam pad, air pad), in different tents in different weather. Also, bags are typically rated for the lower "survival" temp rather than the higher "comfort" one.

I use a silk liner which adds a little warmth because it keeps my bag cleaner thus the loft loftier, warmer, and can be all that's needed on warmer nights. To avoid twisting, get in it first and tension it out like a potato sack race, then get in your bag. Don't stuff it in the bag and then try to get in any more than you'd stuff your base layer and fleece into your coat and then try to put it on.

Systems and interactions.
If your goal is staying as warm as possible, think through how heat transferred and how to minimize it. Convection - dead air insulates while moving cools. Baffles are one dead air pocket, but you can have others within a bag due to a liner. Breezy tents are colder tents, while woods and windbreaks are less breezy. Conduction - sleeping on a rock slab will suck the heat out of you (nice in the shade on a hot day) as will wet clothes or gear from precipitation or perspiration. Radiation - ... Think of how heat is generated, and maximize that (food, hot water bottles, ...).

You do not keep warmer by wearing less ("skivvies"). Wonder if that started with people getting out of wet clothes to sleep then mis-attributing the "warmth" to removing clothes versus removing conductive dampness. Wearing dry, lofty clothing will keep you warmer -- increasingly, cotton shirt, flannel, fleece, puffy. Sweat and body oils reduce loft (including that from body hair), so both cleaning up and clean clothes before the sack helps, as well as prolonging the life and interval of sleeping bag washes.

Considering that, you can see how a grungy "potato" sheltered under a tarp on an exposed slab with a 20F bag in skivvies could be colder than one cleaned up in a tent on a thick pine needle bed in the woods with a 40F bag.

[CamKelley]

Thanks for the replies everyone.
TallGrass awesome read. I understand the variables, i just meant by experience but I guess that proves asking 5 people isnt a good enough control group. I sleep on a 3/4 thermarest with my pack usually under my feet. The sleeping in underwear has proven positive for me just for the sweat factor. Too much clothing and I sweat making me cold. The foot insulation is also a positively tested in my personal experience. I've found it true in lots of places even at the house. The difference in socks/no socks is night and day. Maybe its just my long and lanky nature with foot circulation problems. Just seems to have worked for me in most all my environments both personal and Military.

I may invest in a liner just for dirty days keeping my bag clean as you've stated, but keeping a bag or quilt in my future purchase list. I'll probably see colder temps in CO than I'm used to so adjustments will have to take place. Thanks for the advice!

[Scott P]

Wonder if that started with people getting out of wet clothes to sleep then mis-attributing the "warmth" to removing clothes versus removing conductive dampness.

There was a time in history when wearing less clothing before getting into a sleeping bag had merit. Polar explorers used to consider it dangerous to get into a sleeping bag fully clothed because their sleeping bags were made of reindeer skins and every tiny bit of moisture brought into the sleeping bag would soak into the leather, never dry, and would build up over the days, weeks, and months.

For example, the book Conquering the Arctic Ice, written by expedition leader Ejnar Mikkelsenin in 1909 about the 1906 expedition, says the following:

Being absolutely safe, one can undress and get naked into the sleeping bag, and thus avoid carrying in moisture from one's clothes.

In the accounts of the 1912 Australasian Antarctic Expedition, Douglas Mawson alludes to something similar as well, though he doesn't mention sleeping completely naked (they were actually using three person sleeping bags, and Mawson was upset when one of the members got into the sleeping bag while clothed).

So, 100+ years ago the idea of removing clothes before sleeping in order to stay warm in the long run did have merit. Unless anyone is still sleeping in heavy reindeer sleeping bags for weeks or months on end, it no longer holds true.

[CamKelley]

I may just have to try that!
I guess my next time out, I'll sleep in my method and clothed to see if I tell a difference.

[TallGrass]

So, ScottP, how are the gals over at ReindeerBagDating.com? Interesting history info, and I totally agree on leather, moisture, plus cold.

CamKelley, play with liner, liner+longwear, along with open/flapped/zipped options to fit you and the given night. Start chill adding where needed when needed.

Few other thoughts to the choir. Baby wipes before bed. Clean feet and don tomorrow's clean socks (old ones air out or go straight to biohazard bag 'til laundry day). Rolled down socks can cover just the forefoot if only toes get cold, rolled up as needed. Start bed like starting a hike -- a little chilled 'cause you'll warm up, and if you start warm you end up sweating. Have an adjustable sleep system (pad, bag, zippers, liner, fleece, ...) as both inner bag and outdoor temps shift during the night. Just the liner in an open bag, bag top flopped over, zipped up, add fleece, etc. as temps drop. Prior comment should've been warmth and cleaner. Find the fabric you like against your skin (nylon, cotton, silk, ...). Buy a white liner for the same reason paper towels are, but not bags; good wash-time indicator ("Hey that maroon color must be from the Bells... back in 2008..." ). Breathing in your bag retains the heat (+) but also H20 (-) lost during respiration -- past an initial shivering warm up could lead to a damper bag. Soon as tent-ly possible, unsack that bag and get it loftin'; same for sunny meal breaks can help too.

Again, when it comes to campsite, location-location-location can make ##degrees difference, and think through what's going on and how gear can be tailored for your needs. Highest capacity/weight is between the ears, and its mountain-full day is a great replay slideshow to nod off too.

[lkk8815]

A bit off topic from the original question, the REI garage sales have some sweet deals on sleeping bags. I scored a 0° Marmot down bag for $95, it's worth checking out instead of worrying about liners.

Also, sleeping in skivies to "stay warmer" was just about the worst advice I heard tried once in the army. Shivered miserably all night lol. Warm layers keep you warmer.

[Voshkm]

I am not sure if this is relevant but your damp clothes are not the only possible source of moisture in your bag. A little clothes could help keep bag dry.