Cold at night

[robing]

A full stomach always helps too, just like those Ready Brek adverts

[Vorpal]

merino sleeping bag liner?

[mercalia]

maybe these? http://www.halfords.com/motoring-travel/tools-diy/breakdown-essentials/body-warmer

[Sweep]

Aldi from time do some excellent synthetic thermal layers. Dry in no time,

As for you mercalia, i thought your favoured solution was to whip yourself with one of your bargain clarks chains

[pjclinch]

Note the main point of a liner is to keep the bag clean, not to keep you warm. It makes a smidge of difference, but only a smidge, and for extra warmth it makes sense to use thicker PJs than a liner. You can also have those double as extra clothing, either in camp or on the route.

To keep the bag clean with a liner, and don't like the feel of silk, you can get pertex or similar which are lighter than cotton and don't absorb moisture the same way. I use a pertex one when I'm particularly yucky (most often sea kayaking, a layer of salt, sweat and sun cream) as they're easier to wash than silk. PJs help keep a bag clean, but if you're not wearing socks and gloves and a hat not as effective as a liner, and if you have been using the PJs as camp/bike wear they won't be as clean as a liner.

Keeping a down bag clean puts off the day it has it has to be washed, which is a Good Thing, but we'd still be talking quite a long time without a liner. With a synthetic you can just chuck it in a (suitably large) machine, so I'd be less fussed.

I use a liner and i like them, but I think people do get a bit overly bothered about how necessary they are ("not very") and how magical they might be getting you warmer. They'll make you warmer about the same as a thin T-shirt (which is certainly noticeable), but won't extend a bag's range significantly.

Pete.

[mercalia]

well the liner I got from Lidl recently not just a cotten fabric, seems it could also add warmth, I was thinking in a bivvy bag might be a good light weight sleeping bag as long as u also wear normal clothes. Will have to try that some time. I did a test like that without liner early April with 6C temp. I think and the only bits that got cold were legs and feet especially.

[mercalia]

As for you mercalia, i thought your favoured solution was to whip yourself with one of your bargain clarks chains

well I wont be alone

[foxyrider]

PJs help keep a bag clean, but if you're not wearing socks and gloves and a hat not as effective as a liner, and if you have been using the PJs as camp/bike wear they won't be as clean as a liner.

You take PJ's on tour? how very English!

I use a liner and i like them, but I think people do get a bit overly bothered about how necessary they are ("not very") and how magical they might be getting you warmer. They'll make you warmer about the same as a thin T-shirt (which is certainly noticeable), but won't extend a bag's range significantly.

A silk liner will typically add @ 5c to the temperature range of most bags and at @£20 is much more economical than buying a higher rated bag for what might be one or two nights on a trip where you need extra warmth. Occasionally i've resorted to wearing t's/fleece to counter low temperatures at higher altitudes but under 1000m i rarely have those issues. OTOH i only camp between June and September so it tends to be warmer anyhow

[Vorpal]

Note the main point of a liner is to keep the bag clean, not to keep you warm. It makes a smidge of difference, but only a smidge, and for extra warmth it makes sense to use thicker PJs than a liner. You can also have those double as extra clothing, either in camp or on the route.

To keep the bag clean with a liner, and don't like the feel of silk, you can get pertex or similar which are lighter than cotton and don't absorb moisture the same way. I use a pertex one when I'm particularly yucky (most often sea kayaking, a layer of salt, sweat and sun cream) as they're easier to wash than silk. PJs help keep a bag clean, but if you're not wearing socks and gloves and a hat not as effective as a liner, and if you have been using the PJs as camp/bike wear they won't be as clean as a liner.

Keeping a down bag clean puts off the day it has it has to be washed, which is a Good Thing, but we'd still be talking quite a long time without a liner. With a synthetic you can just chuck it in a (suitably large) machine, so I'd be less fussed.

I use a liner and i like them, but I think people do get a bit overly bothered about how necessary they are ("not very") and how magical they might be getting you warmer. They'll make you warmer about the same as a thin T-shirt (which is certainly noticeable), but won't extend a bag's range significantly.

Pete.

The merino Cocoon is supposed to add about +7 degrees C to a sleeping bag. They have this handy chart on their website that shows how liners improve performance. The only one that gets more improvement is the Thermolite radiator. http://www.cocoon.at/eng/show.php?doc=c ... d=90&fab=0

Having layers; that is clothes plus a liner will generally be an advantage over just thicker clothes because it is the retention of air that insulates. Multiple layers will usually insulate better than a single layer, even if the single layer is thicker than the multiple layers. Of course this is also dependent on the materials, as some materials do this job better than others.

[pjclinch]

PJs help keep a bag clean, but if you're not wearing socks and gloves and a hat not as effective as a liner, and if you have been using the PJs as camp/bike wear they won't be as clean as a liner.

You take PJ's on tour? how very English!

Oh yes, old chap, striped flannel ones with a pocket I put my handkerchief in.

(or, with brain turned on, any clothes I happen to be sleeping in)

I use a liner and i like them, but I think people do get a bit overly bothered about how necessary they are ("not very") and how magical they might be getting you warmer. They'll make you warmer about the same as a thin T-shirt (which is certainly noticeable), but won't extend a bag's range significantly.

A silk liner will typically add @ 5c to the temperature range of most bags

Well, so you say, but what is lacking is how a thin piece of silk is going to do that. If a manufacturer could add 5 degrees to the rating by just adding an additional thin silk inner then that's what they'd be doing! But they're not.

There's nothing magic about silk or making it in to a big sack. To insulate you'll want it to be effective at trapping static air, and while it does that a bit it's only a bit because you just don't have the thickness. I'd suggest your 5 C is somewhat optimistic, based not only on personal experience but the basic physics underpinning it. Also stop and have a ponder about why silk PJs are sold as something cool for hot weather, rather than warm for cold weather.

If you want to add noticeable warmth, wear thermals designed to trap air, rather than sleep in a very thin sack that isn't.

Pete.

[NATURAL ANKLING]

Hi,
Agreed .................some ones been on the drink or has read two many blogs................................

If only it were true

I remember my night on the Cheviots with my square " Woollies " sleeping bag.

I had no Mat
A cheap "Campari single skin + a basic fly tent.
I took off my jeans and jumper and laid them under my bag and my shirt was wrapped around my neck.

Shivered all night, 2 O'clock and the water in my can was frozen.....................................

If you ever get caught out that's better than wearing your clothes in the bag.

SO WHY DON'T marines wear silk jamies......................................They of course go Commando...................so do I.........

[pjclinch]

The merino Cocoon is supposed to add about +7 degrees C to a sleeping bag. They have this handy chart on their website that shows how liners improve performance. The only one that gets more improvement is the Thermolite radiator. http://www.cocoon.at/eng/show.php?doc=c ... d=90&fab=0

I'd be interested in exactly how "supposed to" has been quantified. It might be with the same test used for standardising sleeping bags... or it may not. We don't really know, but one is mindful that among sleeping bags not using the standardised tests there are some remarkably optimistic claims. Having said that, the Merino liner there is half a kilo, which is the weight of a moderately serious down jacket, so it damn well ought to make you a bit warmer!

Having layers; that is clothes plus a liner will generally be an advantage over just thicker clothes because it is the retention of air that insulates. Multiple layers will usually insulate better than a single layer, even if the single layer is thicker than the multiple layers. Of course this is also dependent on the materials, as some materials do this job better than others.

The point about multiple layers isn't that they work better in keeping you as warm as possible, but that they work better in keeping you as warm as you want to be over a large range of temperatures. If you're too hot in 3 jumpers, take off one and that's fine. If you're too hot in a down jacket take it off and now you're too cold because it's all or nothing. But if you want to be as warm as possible the downie will see you better than the three jumpers, because it will trap more air.

If you add a layer in the form of a thin sheet of silk the air trapping of the whole system is not really changed much. Because it's a sack there's plenty of dead space possible for convection currents so it's less efficient than the same material cut close as clothing. And if you have clothing rather than a liner it's useful as, well, clothes.

The main virtue of a silk liner is it's thin enough and sheer enough to take up hardly any space and weight while remaining comfy and keeping the pit clean. Certainly heavier silks will be warmer (thicker, so more air trapping), but unlikely to be warmer than a thermal shirt and leggings actually designed to keep you warm and trapping heat right at the skin for better efficiency.

The most efficient way to be warmer is a higher rated bag, because down is the most efficient insulator in the system. Take a look at http://www.mountain-equipment.co.uk/exteme-sl and note how the comfort ratings are 5 degrees apart. The difference is 150 grammes of very high quality goose down, and I'm afraid I don't buy that a thin silk sheet will make the same difference as 150g of top grade down.

Pete.

[foxyrider]

maybe my bloods thicker than yours!

[pjclinch]

maybe my bloods thicker than yours!

I tend not to use all of these extras myself on a routine basis, but different people do sleep relatively cold or warm.

I used to have an ME Iceline, which I bought after getting bloody cold one night in Glencoe in a 3 season bag when it hit about -20. Over the subsequent 7 years I managed one night with the zip done up all the way, somewhere around -25 outside and my tent-mate spending the night shivering in two sleeping bags while I was toasty (it was actually nicknamed "the Toaster"). I'd done up the shoulder collar but not the hood, but I did wear a hat. I eventually sold it on because it was just too darn hot, but I sold it to a pal who really likes its extra horsepower. While I still had it I lent it to another even colder sleeping friend who liked to use it in summer and had it zipped up while I was wishing my Dewline (with 1/3 of the filling) had a zip. She eventually "made do" with a Rab Classic 1000 her dad had spare. God knows what she'd have needed to go snowholing!

Pete.

[Vorpal]

The most efficient way to be warmer is a higher rated bag, because down is the most efficient insulator in the system. Take a look at http://www.mountain-equipment.co.uk/exteme-sl and note how the comfort ratings are 5 degrees apart. The difference is 150 grammes of very high quality goose down, and I'm afraid I don't buy that a thin silk sheet will make the same difference as 150g of top grade down.

Pete.

The most efficient way to be warmer is a higher rated bag, but the problem with sleeping bag only is that it may mean owning, or even carrying multiple sleeping bags.

The OP is in Norway, and could encounter a 15 or 20 degree difference in night time temperatures this time of year between near sea level and in the mountains or on a high plateau. Personally, I'd rather the extra weight of a sleeping bag liner for additional warmth than an extra sleeping bag. If the merino liner weighs too much, maybe one of the thermal ones that have a similar warmth improvement, but weigh less. Wearing an extra layer of clothes is a reasonable alternative, and it's probably the first one that I would try. But I'd rather have a sleeping bag liner than wear all of my clothes at night. I also don't want to have to take off 3 layers to wee if I can help it.