Be honest with me Do I really need a -40 bag for winter?

Discussion in 'Sleep Systems' started by Moondog55, Nov 19, 2017.

  1. Moondog55

    Moondog55 Guide

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    This question and trying to assemble a deep winter outfit from 20k' klicks away is starting to drive me a little crazy and I need no help in that direction already being considered a little on the weird side.

    I have a selection of good gear but no matter what I play around with it seems that unless I am willing to drag 7 kilo of sleeping bag and mattress around I can't obtain a -40 conservative rating and I really can't afford a new Snowy Owl from Feathered Friends
    If I have to buy an new overbag I will but how likely is it to get that cold anywhere South of the Arctic Circle?
    I'll be dragging this gear on a pulk and with 14 days planned food and fuel plus an emergency amount I really need to keep my weight as low as is safe and practical.
    Destination plans are not yet finalised but I'd like it to be the Gates of the Arctic NP and the lower parts of the Brooks Range if possible
    I'm happy to regard what I have to be rated to -30C for comfort but it weighs almost 6 kilos mattresses included and that is 2 kilos too much I think
    Let me know if I should add links to all my other questions on the subject, because I have been asking this or similar questions for about 15 months now and I am still confused
     
  2. DKR

    DKR Scout

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    If you plan on camping in the Brooks range in the winter, -40 would be the minimum.

    It can hit -70F in the interior of Alaska. I've camped out in the extreme cold @ the USAF survival school, and that was in stacked mummy bags and inside of a snow shelter. You better have a good stove that you know inside-out. You'll need it to melt ice or snow for all of your water.

    I hope you are going to travel with someone local or at least very experienced. I worked as a Medic in a small Airborne unit when I was first stationed in Alaska - frostbite comes quick and is incredibly painful.

    If I may make a suggestion - start camping in less severe weather - working up to the extreme cold.

    Otherwise, best of luck.
     
  3. ANFwoodsman

    ANFwoodsman Supporter Supporter

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    If you are traveling into that area, then I'd say it is worth having a proven bag in your pulk. What bag and pad were you considering?
     
  4. YukonMusher

    YukonMusher Scout

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    +1 on what @DKR said about temperatures to be expected in interior AK in the winter. However, that also depends on when in winter you want to go. Dec, Jan and Feb are almost certainly colder than March and April (no guarantees of course).

    We mush dogs and do snowmobile and ski/snowshoe tours in the interior of AK and Canada's Yukon and we haul -40C/-40F sleeping and clothing systems.

    One way to do it is to combine two lighter sleeping bags ( I successfully used two -5 C bags combined in -40C weather). I find that an economic way, but not the lightest. If you need lightweight, you should go down sleeping bag. I bought a good quality -30C bag and had it refilled and beefed up with some additional down to make it a -40 bag. Worked well for a reasonable price!

    If you use down on a longer (5+day) expeditions, you should put some thought into how to keep it dry or get it dry, if it happens to get damp/wet. This is your life safer piece of gear! You will sweat into your sleeping bag and eventually your down will get damper and damper and lose it's insulation value. If you have a heated tent or plan to stay in cabins (at least sometimes), you shouldn't have problems getting things dry. But if you plan on cold camping, you should really plan this properly! In that case I would look into a vapor barrier inside your sleeping bag. Certainly reduces your comfort ('cause you will steam bath in your own juices...hmmm), but keeps your sleeping bag warm and safe throughout your expedition.

    For winter use in dry cold climate (like interior AK) I would prefer down over synthetic filling. Down is lighter and your bag will likely last for the rest of your life, if you take good care of it. Synthetic bags lose their loft fairly quickly, in my experience.

    As far as mattresses go: In really cold weather I leave all self-inflating stuff at home! The foam cores are usually so stiff that they don't expand and "inflate" the mat. So you need to blow them into shape. Try to blow into a mattress in -40C weather! Good luck! When your cheeks are cold, you cant even build the air pressure in your mouth to blow into that valve! And if you could, you will continue to blow moisture into the valve. After a few days in those temps I found valves just freeze shut.

    I have no experience with those Exped down or synthetic filled mats. They may be great nowadays. A friend had one of their first generations...seams fell apart in -40C and the mat was useless! Maybe the newer versions are better.

    My favorite is the Thermarest Z-rest mat. It's a folding foam mattress that looks like an egg carton and it is fairly light. The folding format works really well in cold weather. Roll-up mats are terrible, cause when the foam gets stiff in the cold, you can't get them to "unroll". They will always jump back into the rolled up shape. In really cold weather I use 2 mats. So if you plan on -40 winter camping, bring two. Caribou hides are also very warm and lightweight! If you can get one or two, you may want to add them to your bundle!

    Good luck!
     
  5. Moondog55

    Moondog55 Guide

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    That's strange Yukon Musher because I used the BPL formula for doubling two -5C bags and got a comfort rating of only -22C and that had me worried, really worried
    If a double bag using two bags rated that high is OK I am fine and the bags are cut to layer.
    I'm not intending to traverse the Brooks Range like a mate of mine did a few years ago, I just want to see where he went in person, I'm told it is very impressive country.

    I can make a VB bag easily, VB clothing ditto if needed
    DKR I'm taking baby steps.
    As for the sleeping bags I was planning on layering my Everest summit bag under a Nunatak Alpinist XL/W, RidgeRest Solar and a 12mm CCF plus my S2S mat which they say is good and flexible down to -45. No foam in those just some thin polyester fibre and double layer construction to minimise convection currents
    I was told to leave the mats and sleeping system flat on top of the pulk/sled [ under the tank] ready to go; does that not work well?
     
  6. Haggis

    Haggis Supporter Supporter

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    I'm certainly no expert, (some here are,,, really), but I'm not going any where any more where the bottom can drop below my bag rating; been there too many times already. No sleep means no energy the next day, and a bag that will let me get a good night's sleep is worth it's weight.

    I can't, or rather won't, afford a $1000 or $1500 lightweight down bag, so my Wiggy's -60 does admirably.

    Cut the weight someplace else, not with your sleep system,,, at least 8 hours a day, it's mother's womb,,,,
     
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  7. Seeker

    Seeker Woods Bum Supporter Bushclass I

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    I spent two weeks in -40F nights/-25F days during an Army training exercise in Upstate NY in the early 90s... I had not been issued the 'normal' USGI ECW sleeping bag (which is a pretty good piece of gear), but some experimental bag with a wonder-material cover (Goretex, the magic fabric. keeps you warm, dry, it's bulletproof, and makes you fly!) and only about 2" of loft, probably good to about +20*F. Day and night shifts combined their bags and sleeping mats, and it was still too cold to sleep. The institutional/organizational/leadership stupidity demonstrated during that exercise (and others) was instrumental in my decision to leave the Army after 11 years of service.

    Loft keeps you warm, be it feathers, leaves, fur, foam, newspaper, wood, or wool matting...

    If you can't afford down, get synthetic... but get a bag rated low enough to keep you warm. As Haggis said, cold sleep will suck the life right out of you, leading to poor decision-making at best, disaster at worst, and a bad trip regardless.

    "I go camping to have a good time, and 1/3 of that time is spent in bed."
     
  8. YukonMusher

    YukonMusher Scout

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    @Moondog55 : I don 't know the formula you are talking about. I just combined the sleeping bags on some of my winter trips, 'cause I didn't have anything else until I bought my proper winter down bag. And it worked! However, YMMV since we all feel cold in different ways. Some people are "warmer" than others. You can also acclimatize your body to colder temperatures, simply by being exposed to them over a period of time. Every winter I feel damn cold at -10C when the first snow flakes fly. But four weeks later, it feels just fine and I will run around in a light shirt. What I am trying to say is that a certain sleeping bag system may work for one person, but not the other. Forget all formulas...! |Biggest issue with those combos is the hood area. I was not able to properly close both hoods over my head and get that very tight. That is where I lost the most heat. My girlfriend used two different bags than me, and she had no issues there. But her bags were also warmer. (-15C + -5C)

    There are also a lot of ways to pimp your bag and improve sleeping while out there! When it is colder, you can wear more clothing inside! I know, some will say: don't wear anything inside but your underwear. I still don't understand that theory! If it is too cold: add insulation! I also use my down jacket as a bag over my feet (with sleeves pulled into the jacket). That makes a huge difference! I also find I lose most heat to the cold ground. So good mattresses are key. If what I have is not enough, I add layers of spare clothing on my mattresses. In super cold I also add a nalgene bottle with warm water, which I place between my thighs to help warm my blood flow. I wear a face mask and a neck warmer. I make sure I am very well hydrated and well fed, before going to bed. I go pee as soon as I need to (I know, it sound silly...but you may be surprised...).

    I am not sure if it works for you to keep the sleeping system open on your pulk. My pulk would not have been big enough. Just try it! Sounds like a good idea...

    Have fun!
     
  9. Moondog55

    Moondog55 Guide

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    I was going to sleep in my down parka if my sleeping bag system didn't cope, my down parka is very warm, about the same as the Feathered Friends Icefall parka
    That picture is of the Everest bag with my parka inside it. Too warm at -25C in the Adirondacks
     

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  10. CharClothed

    CharClothed Supporter Supporter

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    I personally love the idea of being warm no matter what.
     
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  11. gohammergo

    gohammergo Still running against the wind..... Supporter Bushcraft Friend

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    I really have nothing of value to add here to be honest. I've never camped in the very cold.

    The only thing I can say is that comfort is the key, and a good night sleep could quite be the highest priority of a trip like that.

    When I camp, the first nights sleep is often not so good. Strange place, strange sounds, the excitement of being out. The next day I feel somewhat zombie like at first. Takes awhile to get my mind straightened out.

    I can only imagine how it would be in that kind of cold. Spending relatively sleepless nights and trying to function in the cold.

    I wish you the very best in luck and hope you share your adventures with us. :)
     
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  12. arleigh

    arleigh Guide

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    I have camped on snow just as a training with Search and rescue .
    Mistakenly I had nothing more than my military down mummy sleeping bag and tent bottom to separate me from the snow I tried to sleep on. I'd gotten more rest setting by the fire keeping it going .
    Years sense I've used a boogie board to lay on ,while working on the snow cats at work and though it is quite stiff, it is far more comfortable than the snow .
    The base of the bookie board is some kind of Teflon surface so it slides like a dream , IMO a great sled for the winter ,regardless of the surface your traversing. plus it is in fact floatation . many I have played with have plenty of tie down handles and a means to secure your gear . this time of year you can find them cheap at thrift stores .
     
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  13. Moondog55

    Moondog55 Guide

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    I was planning on using a Paris Expedition sled as the basis of a pulk, I suppose I could cut a section of foam wall insulation to fit into the base of the pulk but I thought a large thick CCF pad would do the same job
     
  14. Moondog55

    Moondog55 Guide

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    Went to the factory shop today to do two things
    Drop in my old bag for a factory rejuvenation and check on an outer bag to use 2 sleeping bags doubled up
    Using my old Everest bag as an inner and this Large shell as an outer we got over a foot of loft, that should be OK even if it hits -60C
     
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  15. mulepacker

    mulepacker Tracker

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    Yes. Travel light freeze at night.

    Mulepacker,
     
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  16. Moondog55

    Moondog55 Guide

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    I have no intention of freezing or even being cold
    But the weight and bulk of a -60C system has been a bit of a shock to the system
     
  17. Moondog55

    Moondog55 Guide

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    Here is a copy of an email that I just sent to a mate in Connecticut in reply to a similar question he just asked me.

    The formula is that from BPL used to approximate the combined rating of doubling up sleeping bags


    I think it is a formula that works well down to 0F, after that I think after all the research I have done that I would simply measure free loft. I would use the US Army insulation tables then, work out how much insulation a fit and healthy 25YO would need, add the extra needed for every decade after that [ plus 12mm/half inch per decade] then add an extra inch for comfort.


    So for me at 65YO that is an extra 50mm of insulation needed; which actually explains why I needed the down half bag to get the -25C rating from my UL winter bag. So to be safe at -30F you really do need to add that margin for age.


    I have been doing a lot of research and the base metabolic rate when sleeping is not related to general fitness when you pass 50YO, it is simply a function of aging and we can't do anything about it except add warmth


    Army tables say that at -20F you need 3.0 inches of insulation or 7 inches of loft; -40F 3'5 inches and -60F 4 inches or 8 inches of loft for SURVIVAL, obviously at least an inch more for comfort; IF you are a fit 25YO


    Talking to other folks lately adding two 0F bags together should be fine even if the BPL formula is pessimistic because 2 layers using 2.5 inches + gives enough loft.


    It is this whole size thing that brings people down I think, it took me 3 goes to get comfortable with the sheer size needed for an overbag, especially if the sleeping bag you already own is big to start with because you yourself are no longer a skinny 25YO and simply need a bigger bag for comfort


    That is the easy part What is really, really hard is finding an outer bag big enough to layer with.


    My outer bag is HUGE, not heavy, simply physically enormous by normal standards.

    The outer bag I have on order is over 6 & a half feet in girth and almost 8 feet long external
     
  18. Blackhawk45hunter

    Blackhawk45hunter Pronounced sim-bee-duh Bushclass II

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    Believe it or not, it’s gotten down to -20f here in southern Ohio in the winter and it routinely gets down to -50 up in the Great Lakes and that’s all WAY farther south of the arctic circle than the Brooks Range.
     
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  19. Moondog55

    Moondog55 Guide

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    I believe you, but I guess I missed all that on my last trip, it was raining a lot of the time, even in Ohio near the lakes in January
    I have extended Family in Cleveland, but we went to see the R&R Hall of Fame anyway
     
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  20. Newtothis

    Newtothis Supporter Supporter

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    @Moondog55
    I had not heard this before. Is this saying a 20* bag will work for a 25 year old but not a 45 year old?
    as a general rule anyway.
     
  21. Blackhawk45hunter

    Blackhawk45hunter Pronounced sim-bee-duh Bushclass II

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    Not as a rule, it’s based on personal metabolism and such. I’ve got buddies younger than me (I’m 27) than can’t handle cold anywhere near as well as me, and I’ve known dudes in their 50’s and 60’s who could sleep colder with less insulation than me any day of the week. Don’t buy into the whole body fat - sleep warmer BS either. Some of my most cold-intolerant friends are overweight to some degree or other.
     
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  22. Newtothis

    Newtothis Supporter Supporter

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    That might be a correlation.

    All in all, I'm just wondering if I should plan for the 20* Slick bag or the 0*. I think I sleep cold as it is.
     
  23. Blackhawk45hunter

    Blackhawk45hunter Pronounced sim-bee-duh Bushclass II

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    That said, I have one buddy who has not an ounce of excess body fat and he needs a winter bag to stay warm when it’s 40 out and I have another buddy who is quite stocky and can sleep in 30* temps with nothing more than a USGI woobie. (For real)



    It really is a case by case thing. Everyone regulates temp differently.


    Unless it’s possible for temps to be significantly warmer than normal, I always shoot for the warmest bag. I’d go with the 0*.
     
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  24. Moondog55

    Moondog55 Guide

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    While we are all different it is true as a general planning tool. Lots of good research into the matter. Have you ever wondered why old peoples homes seem so warm to you? It's simply that us old folk in general generate less heat internally when we are sleeping.
    Better a little too warm that too F******** cold
     
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