So, I've been carrying a blizzard survival bag for a while, mostly on solo trips, and/or to remote areas, or to where it's easy to imagine getting stuck in wet/cold conditions. I used to carry lots of extra clothes, but finally faced the fact that I very rarely wore any of that stuff, and the extra clothes were probably not enough for anything but mild conditions, if I were not moving. The 13.8 oz for the emergency bag is lighter than all the extra stuff I used to carry.

I'm now moving toward making the survival bag an almost constant part of my emergency gear; but I still pack pretty light. So would like some advice on one important issue:

I need a warm pad to keep me from freezing my ass off, if I have to use the bag. I'm trying to keep all this stuff so light that I'm not tempted to leave it behind.

I know that one of the best ways to make sure you have a pad is to use a rucksack with a removable pad. Well that could help somewhat; but I use a wide variety of packs, and none currently have removable pads. Besides, I'm already planning on using the pack as part of the under-body insulating system.

So what I'm thinking of is this:
Gossamer 19"x29.5" torso pad (folds to 10"x19") -- just 2.5 oz.

It looks like this pad would even fit along the inside back of my REI Flash 30. I've never seen this thing, less used it or know what it is like.

Another possibility is to cut this in two. (2 oz, if I believe REI)

Ideas?

I use three fiths of a z-ridge pad, folded into thirds stuffed into my aging Serratus Genie. Unfolded, the pad fits my shoulders to my hips and makes a decent bivi pad for mid summer overnights.

ExcitableBoy wrote:I use three fiths of a z-ridge pad, folded into thirds stuffed into my aging Serratus Genie. Unfolded, the pad fits my shoulders to my hips and makes a decent bivi pad for mid summer overnights.

Thanks, I've thought about that. I don't have an old one, but might buy one just to make a 4 oz (2/5) and 6 oz (3/5) pad.

If I don't plan to use it often, I might go for laminate flooring foam underlay:
http://www.instructables.com/id/How-to- ... -underlay/

It's very cheap, so not much expense in trying.

The cheap blue foam pads are probably not ideal as they are not warm (especially compressed after several uses) and are less conveniently stored than the folding option.

Remember, I'm not aiming to use this system for regular bivys -- the blizzard emergency bag can be reused, but it will never be back to the same packed size; it's really an emergency item. So it's OK is the foam pad gets used only once (or a few times) as an actual sleeping pad.

I bet just by wandering around your local home improvement store you could find a number of interesting materials to try. I saw some mylar 'bubble wrap' type material that was tough, light, and cheap and seemed to give a bit of cushion. No idea how the insulative value is though.

MoapaPk wrote:

ExcitableBoy wrote:I use three fiths of a z-ridge pad, folded into thirds stuffed into my aging Serratus Genie. Unfolded, the pad fits my shoulders to my hips and makes a decent bivi pad for mid summer overnights.

Thanks, I've thought about that. I don't have an old one, but might buy one just to make a 4 oz (2/5) and 6 oz (3/5) pad.

If I don't plan to use it often, I might go for laminate flooring foam underlay:
http://www.instructables.com/id/How-to- ... -underlay/

It's very cheap, so not much expense in trying.

Also very thin. For what you're talking about using it for, it's probably worth about what you'd pay for it! Bubble wrap would give you better bang for your buck.

Buz Groshong wrote: Bubble wrap would give you better bang for your buck.

I've seen it reviewed relative to other materials. It is extremely bulky and not very good at insulation... and if not "bang," it tends to give a lot of pops for the buck!

I looked at the floor underlayment -- very cheap, but the "gotcha" was that you have to get an entire 100' roll. It's so light, that I would have tried enough for at least two layers. I just went ahead and ordered the Gossamer Gear pad.

MoapaPk wrote:

Buz Groshong wrote: Bubble wrap would give you better bang for your buck.

I've seen it reviewed relative to other materials. It is extremely bulky and not very good at insulation... and if not "bang," it tends to give a lot of pops for the buck!

I looked at the floor underlayment -- very cheap, but the "gotcha" was that you have to get an entire 100' roll. It's so light, that I would have tried enough for at least two layers. I just went ahead and ordered the Gossamer Gear pad.

Other than a vacuum, some sort of aerogel, or fluorocarbon-filled foam, you can't get a decent insulation value without bulk. So the best you can do is to get something that is light. That says that your best bet would probably be to cut down a regular sleeping pad.

Oh, and insulation values can be deceptive - when insulation is on top of a warm body in a cold environment, convection can degrade the insulating value of something like bubble wrap, but between cold ground and a warm body convection is not really a factor. So, for this purpose, it's probably better than whatever values (R-value, k-value, or u-value) you are getting for it.

Many people like bubble wrap; I didn't for a few reasons; one is real, the others may be over-thinking.

Real:
1) I tried laying on bubble wrap on the hard linoleum floor of our lab, and simulated getting up and down in a limited space. In not long, I had managed to pop a lot of the bubbles under my butt and shoulders and elbows as I left the "tent."

Overthought:
2) the channels between the bubbles are connected and rather wide, and can undergo forced convection when you move.
3) the bubbles are fairly large, larger than the recommended 1/4" max for insulation air space (maybe I should calculate the Rayleigh number and do a stability analysis ); and they deform, so rolling over them can produce forced convection within a cell (if not just buoyant, heat-driven convection).

Extra credit:
4) I couldn't resist the urge to pop the bubbles.

MoapaPk wrote:Remember, I'm not aiming to use this system for regular bivys -- the blizzard emergency bag can be reused, but it will never be back to the same packed size; it's really an emergency item. So it's OK is the foam pad gets used only once (or a few times) as an actual sleeping pad.

But in an emergency, wouldn't you want every advantage you could get?

If this was a concern of mine, I'd follow along the lines of excitableboy. I'd get a Cascade Designs SOLite foam pad and chop it to fit my pack. I've had one of them for about a year now, and I'm super surprised by how warm the thing is in most conditions. Shoot, get the large and make a couple for your different packs.

I think Buz was talking about the bubble wrap that is between two layers of silver mylar, which is more durable and has better insulating value that shipping bubble wrap. I found this works well in a pinch for wrapping water botles and whatnot, but is of course not as durable as something specifically designed for that purpose. But again, it is light and cheap....it's all trade offs, huh?Personally, I'd probably cut a z-pad down, not the lightest, but bomber.

crackers wrote:

MoapaPk wrote:Remember, I'm not aiming to use this system for regular bivys -- the blizzard emergency bag can be reused, but it will never be back to the same packed size; it's really an emergency item. So it's OK is the foam pad gets used only once (or a few times) as an actual sleeping pad.

But in an emergency, wouldn't you want every advantage you could get?

If this was a concern of mine, I'd follow along the lines of excitableboy. I'd get a Cascade Designs SOLite foam pad and chop it to fit my pack. I've had one of them for about a year now, and I'm super surprised by how warm the thing is in most conditions. Shoot, get the large and make a couple for your different packs.

I have one of those pads-- the full length version is 4 oz heavier than my 1995 (or earlier) ridgerest, about a lb, so I plan to use the aluminized version only for snow camping. I've been comfortable with the old one in 20F weather. I realize one might cut it down for emergency use, but it's still extremely bulky. Even cut down, it would take up most of the space in my pack, partly because it just rolls.

If I were planning on any significant chance of a bivy, I would have something better than a blizzard survival bag. A big attraction of the blizzard bag is that before the seal is broken, it packs very small. Remember I'm trying to keep this light enough that it becomes a permanent part of my emergency kit. My normal day pack is 30L, and it is normally stuffed to the gills. In an emergency, the pack itself would become part of the insulation, and I'd likely scrounge for conifer boughs, and might end up half-sitting through the night.

CBakwin wrote:I think Buz was talking about the bubble wrap that is between two layers of silver mylar, which is more durable and has better insulating value that shipping bubble wrap. I found this works well in a pinch for wrapping water botles and whatnot, but is of course not as durable as something specifically designed for that purpose. But again, it is light and cheap....it's all trade offs, huh?Personally, I'd probably cut a z-pad down, not the lightest, but bomber.

We actually have a roll of that stuff-- we use it to make reflective window blocks for cars (it's fairly hot here in southern Nevada-- unless you are in the nearby 11-12k' peaks). I ruled it out because it is not really very light... but maybe I'll cut a piece off now and rethink. It might be good for a back rest, even just a 12"x18" piece-- but I'd probably have to examine it for rips after each trip, even if I just leave it in place. My pack gets ripped nearly every trip-- my biggest worry with the Blizzard bag is that the vacuum-packed plastic case will get ripped by normal wear as it bounces around the pack. (My old one-layer mylar emergency sack, even though it has never been taken out of it's think plastic bag, has become de-aluminized on the edges.)

EDIT: Ok, just cut a 19" x 20" piece of the mylar-reflective bubble wrap, doubled it over and put in the back of my 30-L pack, behind the small flap for the hydration bladder (which I don't use). The aim would be to pad the area from my rump to my shoulders, and use the pack itself for the rump.

Likes:
--for this piece, just 2.3 oz
--easily foldable and stiff
--cheap

Dislikes:
--fragile. I popped a bladder just putting stuff in the pack, and there were 4 spots already popped in this small piece (which I cut out of a "new," still-packed roll), apparently just from packaging and transport