View Full Version : Sleeping Bag Liners
Mitey Mo
06-06-2013, 17:16
I am a cold sleeper. I hammock. I've got the under insulation figured out. I use a Wally World Blue pad and a truck sunshield. Works fine. BUT...I get darn cold through my sleeping bag...on top. I have a down Marmot 15* bag but froze when it got down to 38* one night. I had long underwear, long thick fleece top and bottom over that and clothes over that. I used a silver emergency blanket inside and on top of me and that helped me get to sleep. I KNOW my bag is too big. I need a women's bag as I am 5'2" and 107 lbs (about the size of an 11 yr old) I have a regular size bag. I will be getting a women's bag sometime soon, but for now I would like advice on sleeping bag liners. Are they worth it? Silk or Polyester?
Last night I slept out in the backyard with a Synthetic 45* bag with long underwear and it got to 60* and I was still a little cold. I am trying out various combinations of bags and clothes to see what works at what temps for me.
So, would a liner add much warmth at minimal weight?
Thanks for any advice.
Meriadoc
06-06-2013, 19:04
Two things to check:
1- You say you are wearing a lot of clothes but in a bag that's large for you. Is the sleeping bag getting compressed at all from the inside?
2- Where are you using the silver emergency blanket? Are you letting moisture escape? You may be trapping moisture inside the down of the sleeping bag and negating its insulation powers.
My polyester liner did little to keep me warm. I have not brought it in a long time. In fact, I should get rid of it. Want it? :P
The warmth to weight ratio is pretty low. I am usually better off bringing a second quilt or a set of insulating clothing.
Please don't take this the wrong way, because I am not trying to be snarky. You may do better with a youth's bag than a woman's bag. It may be tough to find, because youth gear is typically "temporary," so there may not be as much high-end stuff. Also, at 5' 2" and 107, your BMI is on the low end of normal. I would guess that you aren't sporting a lot of personal insulation :^). Do you have a small snack before bed? A Snickers and a hot chocolate might help. You could also sleep with a bottle of hot water.
Assuming that you aren't compressing the bag's insulation and that the bag is in good shape, your heat loss should be managed. A smaller bag would give you less space to heat up. Then, all you can do is manage heat production -- stoking you body's furnace, adding hot items (rocks, water bottles, pocket warmers), etc.
Good luck. There are worse problems to have than being thin :^)
pelenaka
06-06-2013, 22:00
You could always rig up a temporary liner to do a test run. I've been sewing myself a liner outta a few thin fleece lap blankets for my Kelty 35 degree bag.
Mitey Mo
06-07-2013, 05:19
Pelenaka, I've thought of sewing myself something. A bag is about as easy as it gets. I would think fleece would be WONDERFUL but I'm concerned about the bulk and weight. I just might try it, though.
Pelenaka, I've thought of sewing myself something. A bag is about as easy as it gets. I would think fleece would be WONDERFUL but I'm concerned about the bulk and weight. I just might try it, though.
Fleece is a little on the heavy side but I still carry a fleece liner. To me it's worth it. I got pill free fleece from Jo-ann fabric and sewed my own to fit me. It's much more comfortable against the skin than the fabric of a sleeping bag. Keeps my bag clean and non sweaty. Easy to wash after 6-7 days out. If temps are not below 55 or 60 it keeps me warm without a down bag. I am a ground sleeper though. Your experience in a hammock may differ.
Teacher & Snacktime
06-07-2013, 07:29
Pelenaka, I've thought of sewing myself something. A bag is about as easy as it gets. I would think fleece would be WONDERFUL but I'm concerned about the bulk and weight. I just might try it, though.
I tried this with ultra thin fleece lap blankets....making the liner was no big deal, but using it was a pain in the tukus.....since I was wearing fleece sleep pants and pullover, everything stuck together and there was no way to eliminate the bunching and grabbing. Either wear something more slippery, or make the liner out of poly or silk.
I agree with all of the comments made thus far. I don't know if liners are "worth their weight" in terms of insulation value. Also, they are just one more dang thing to tangled up in as you sleep. HOWEVER, I often bring one with me (usually silk--but I have a couple of other ones too). I find it helps keep my quilt or sleeping bag a bit cleaner--and MAYBE adds another couple degrees of warmth.
My theories regarding your "cold" sleeping:
1. I agree with others that you are small and are perhaps trying to heat too large of an area by using a regular sized bag.
2. I agree that by wearing so much stuff--you may be actually impairing your own circulation and/or compressing the insulation value of the clothing and/or the insulation value of your sleeping bag.
3. I typically use a quilt in my hammock. HOWEVER, if I use a sleeping bag, I tend to open it up and use it over the top of me--similar to a quilt. In a hammock, I find that opening up the sleeping bag like a quilt is usually warmer (for me) than using the sleeping bag in the traditional manner. (Actually, I often just unzip the bag MOST of the way--and use the partially zipped bottom part of the bag as a cozy spot for my feet.
4) Decades ago, I met plenty of people who were convinced that wearing LESS clothing in a sleeping bag was often warmer than wearing more clothing. The theory being that the only warm thing inside the sleeping bag is YOU. Sleeping bags don't generate heat--you do. The air space and "loft" of the sleeping bag just traps the warmth generated by your body and insulates it from escaping (and it also insulates you from the colder air which is outside of the bag). Since YOU are the only thing that heats the air space inside of the sleeping bag, the theory is that if you wear lots of clothing inside the sleeping bag you are keeping the heat and warm air trapped right next to your body. Thus, a great deal less warmth from your body escapes from the clothing to heat the air space inside the sleeping bag. Think of it this way...Imagine that you heated up a couple of hot water bottles to put inside your sleeping bag to help provide you with additional warmth--but you wrapped the hot water bottles in so much insulation that the heat from the hot water bottles never escapes to help heat you!
DeerPath
06-07-2013, 09:36
I am a cold sleeper. I hammock. I've got the under insulation figured out. I use a Wally World Blue pad and a truck sunshield. Works fine. BUT...I get darn cold through my sleeping bag...on top. I have a down Marmot 15* bag but froze when it got down to 38* one night. I had long underwear, long thick fleece top and bottom over that and clothes over that. I used a silver emergency blanket inside and on top of me and that helped me get to sleep. I KNOW my bag is too big. I need a women's bag as I am 5'2" and 107 lbs (about the size of an 11 yr old) I have a regular size bag. I will be getting a women's bag sometime soon, but for now I would like advice on sleeping bag liners. Are they worth it? Silk or Polyester?
Last night I slept out in the backyard with a Synthetic 45* bag with long underwear and it got to 60* and I was still a little cold. I am trying out various combinations of bags and clothes to see what works at what temps for me.
So, would a liner add much warmth at minimal weight?
Thanks for any advice.
I have a silk liner and it works great. Don't know if it really gets 10 degrees lower, but it really makes a difference.
Happy Trails
Kerosene
06-07-2013, 09:47
I've found that silk liners don't seem to add much in the way of warmth: 5 degrees maybe. They're better for keeping your bag clean (skin oils eventually compress the loft) and I've found that it helps to eliminate the little cold spots around my neck when it's too warm to cinch the sleeping bag hood tightly. That said, I rarely bring a liner anymore in order to save 6 ounces.
My second night out in my new, high-end (read expensive) Western Mountaineering UltraLite 20-degree bag was in Georgia as the temp dropped below freezing. I wore everything I had to bed and was still so cold that I didn't get much sleep. Since then, I only will wear long johns to bed and have been much more comfortable on the coldest nights, as I think the extra clothes either compressed the loft and/or kept the bag's interior from heating up.
FarmerChef
06-07-2013, 10:49
I use a silk liner and agree with others that it gives maybe, maybe 5 degrees of bump. It's very light and it does help keep the bag cleaner. Plus if it's really warm (not the issue here) I can just sleep in that with the bag open.
With regard to what others have said, it sounds like you're a little small for the bag you've got and fighting a losing battle to heat the air in the bag. And I strongly recommend having a complex/simple carbohydrate snack right before bedtime. I really feel it when I don't and it's amazing how much warmer I sleep when I have it. Snickers snack size bars are great for this. A granola bar could work as well. If you wake up absolutely cold in the middle of the night, consider having another snack before going back to bed. You're in a fasting state by early morning and your body doesn't have as much to generate heat with. Getting that snack without waking everyone up....that's another story ;)
Mitey Mo
06-08-2013, 05:19
Thank you so much, everybody. I've just ordered a Big Agnes Petite Synthetic 0* bag. 4 lbs but I gotta stay warm! Being afraid of being cold is keeping me at home! I, also, have heard the theories of less clothing being warmer and I was actually trying that out in the backyard this week. I will continue to do so until I feel comfortable enough to go "out there" by myself. The neighbors must think I'm nuts, (my family does), but I don't care :).......Hey! I've just found my quote!!!!
Thank you so much, everybody. I've just ordered a Big Agnes Petite Synthetic 0* bag. 4 lbs but I gotta stay warm! Being afraid of being cold is keeping me at home! I, also, have heard the theories of less clothing being warmer and I was actually trying that out in the backyard this week. I will continue to do so until I feel comfortable enough to go "out there" by myself. The neighbors must think I'm nuts, (my family does), but I don't care :).......Hey! I've just found my quote!!!!
Good for you MM. That's that way we learn.
rocketsocks
06-08-2013, 06:40
The neighbors must think I'm nuts, (my family does), but I don't care
You have officially crossed over...welcome, and congrats.....your in good company :)
I picked up a Grand Trunk silk liner. Amazingly warm. small and compact, even has a sewn in stuff sack. Great for just hot summer sleeping also.
Regarding the hypothesis that "less clothes will keep you warmer," that is false UNLESS the additional clothing constricts your blood flow or compresses the insulation. If you can avoid those conditions, more clothing adds more insulation and keeps you warmer. A quilt with enough room to add insulating layers creates a versatile sleep system. When it's very cold, add all your layers. When it is warmer, use fewer. You can also pull the quilt tighter and reduce the air space you need to warm up, but not past the point where there is any constriction.