Waterproof down blankett??

[DanDan The man called Dan]

I was just having a think rather than working like I'm supossed to be. I like to use a tarp , sleepmat bag and bivvi combo when out and about but I also like the idea of just using a lightweight blanket.

Instead of sleep Mat, Sleeping bag, bivvi bag etc..I'm thinking waterproof downblanket and sleeping mat.

I guess it would need to be completely waterproof though to stop any moisture getting the down or perhaps complete water barrier of some sort of material oneside and goretex the other but would there be any adverse/negative effect on the warmth benifit of the down.

Good idea/bad idea????

Dan

[tedw]

My vote: BAD!:(

Down + damp = cold:eek:. I doubt you could keep the down dry in outdoor conditions. Breathable fabrics are not 100% waterproof and a truly waterproof top layer will likely get condensation from your body heat on the inside surface which would then soak the down.

Sorry to puncture your balloon!

[andy_e]

Not entirely sure how a breathable upper on a down blanket, as Dan is suggesting, is *that* different to using a down sleeping bag inside a breathable bivi-bag. Have never had a problem using down bag and breathable bivi combination myself, most of the dampness I've experienced has always seemed to come from me not the outside.

As far as I can see, the main issues are ensuring you stay warm and draft free and of course ensuring that no rain/splash/moisture soaks the down from the sides, as you don't then have that *enclosure* of the bag. So, I think you'd have to either make it wider than it strictly needs to be or build in wings to tuck under you, like the Wanderingstar hammock blanket and others.

If you're using a tarp as well then it seems quite similar in some respects to the top-only sleeping bags that ultra-lighters go for.

If you planned not to use a tarp at all then I'd say you're better off with a bivi.

It could be an expensive experiment but then again it could work really well for you.

[wentworth]

If you're using a big tarp (8x10'), then you don't need a waterproof blanket. Generally down gets a bad rap from people who can't keep it dry or have never tried it.

I used my down quilt for two solid weeks of rain and had no problem. I was using a 10x10' tarp closed like a tent.

Note, one quilt maker is using cuben, a waterproof non breathable material for his quilts, with a strip of waterresistant/breathable material on top to allow the quilt to loft up. This means the quilt acts as a vapour barrier.

And waterproof breathable membranes like goretex are waterproof. In that their pores are actually smaller than water molecules. If they're smaller, water can't get through. If you sweat inside it, that's another issue. Sweating inside goretex is commonly blamed on it not being waterproof.