Non-emergency use of space blankets

[stevage]

I seem to recall seeing space blankets showing up in some people's ultralight pack lists, and not just for emergencies. How well does this work? Anyone use a space blanket to keep rain off? How many times can you use one? Other comments or suggestions?

I'm very curious, and bought one when I saw how cheap and light they are. Slowly tiptoeing towards tentlessness... I was thinking of going with just a sleeping bag (synthetic I guess), exped downmat, and space blanket for an overnighter where I'm not expecting it to rain.

[Lonesome Luddite]

I have used an Adventure Medical Thermolite Bivvy on a couple of trips with mixed results (http://www.adventuremedicalkits.com). 

One was a weeklong kayaking trip at Isle Royale in Lake Superior.  Temps were in the high 50s at night and I was reasonably comfortable with long underwear and the bivy.  I woke up damp a few times because the bag isn't very breathable (especially if I tucked my head inside), but I didn't suffer too much for it. 

The other was a minimalist overnighter on the bike to a nearby trail/campground.  It was the 4th of July and I was expecting temps in the 70s at night, but just as I was falling asleep a huge T-Storm hit and temps dropped into the low 50s suddenly with heavy wind and rain.  I was using a poncho as a tarp and it didn't provide as much protection as I would have liked.  The bivy kept me from getting hypothermic, but it was one of the most miserable nights I've ever spent out. 

One of these days I'll drag it out and try it again.

[stevage]

Ah yes, that looks a bit bigger and fancier than I bought. My thing weighs almost nothing and folds to perhaps 5cm by 4cm by 2cm.

Your data point is very informative, though...

[AZTtripper]

I had one of these for the AZT in 06 I destroyed it the first time I used it (they claim to be 30% stronger now).

I am not a big fan of space blankets as they are not breathable and you end up wet.

I can see a use for them as a safety item for long days but I wouldn't want to use one much.

With a synthetic you should be fine as the bag is still going to keep you warm even if you are soaked in your own sweat.

Lately I have been using down bags and I like to keep dry. I used to use an REI bivy sack with a small tarp for over my head. Then a poncho replaced the tarp but now I have one of these http://www.seatosummit.com/products/display/61 it is small when stuffed but makes a good sized shelter (not the two person they say but one for sure) I think i can stay dry under it so I dropped the bivy. I took it on the Coco 250 but never did need it so I can't say for sure yet how it will do in a rain. Hopefully we will get some rain soon (we always need it) and I can set it up near the house and see how it does.

[Mike Brown]

It wouldn't exactly be an emergency- I've come really close to using mine as insulation in the bottom of my hammock in sub-30 temps. I've figured out other solutions since (better sleeping pad).  I would still consider this use if necessary.

[jeremy11]

The small ones are really fragile, I consider them one time use.  One time I tried one as a ground cloth - on slightly sloping snow.  It was like sleeping on a sled.  For single overnighters it could be done with care and style, but I wouldn't plan on more than one night.

[Pivvay]

The emergency blankets are crap but the heatsheets stuff works great for $15 and 3.5 ounces plus they pack tiny. I've used one as a bivy and groundsheet for a while. Not really good with a down bag inside as you get wet but it works in a pinch when you don't expect rain or on their own for short sleeps and not crazy cold temps. I bet in the 40s you could easily do a short race with one. Jefe does long races with them but he's a manimal.

For a race longer than ~3 days I would bring a "real" bivy if I was going to bring a sleeping bag. For short races or times with no sleeping bags, the heatsheets get pressed into service and work for me. Mine has a couple packing tape patches but I bet it's been used at least a dozen times overnight. It's worth having in the pack for possible benightment too. A heck of a lot of warmths and wind protection for 3.5 ounces.

[wookieone]

Hey I have used a couple different E-bivies. The space blanket ones are, as mentioned, very fragile, and noisy. I used another I believe mentioned above, it is a weaved material that reflects and has a touch on insulation. This puppy was warm! But it too does not breath and after even a few hours gets pretty wet inside. So they work, but don't breath, an ok emergency add on shelter, but again not good with down and after one night not so welcoming at the end of the day! I am unsure what I will be sleeping/napping in next season, but something breathable, but still freak out how big even 1# down bags are! Man I am sick if I can legitamatley say that! So maybe a sleeping bag/bivy combo, but all that stuff for only 2-4 hours of usage a day, that could be food, or batteries,or......hey, peace JEFE