Keeping dry in a snow cave?

[Vern]

Hi,
I am looking to hike into Mt Field again this winter and will be staying in a snow cave. In the past I have just used a plastic drop sheet to keep my sleeping bag from getting wet.
Does anyone know of any cheap alternatives to this? I was contemplating purchasing and wrapping an AMK Thermolite 2.0 around my sleeping bag?

[Azza]

Orange plastic emergency bag, I assume you can still get these.
Only one step up from a plastic drop sheet but at least its enclosed.

Something like this..
http://www.outdoorgear.co.uk/eshop.asp? ... =MAIN_DESC

wow... there is a even a wikipedia article...
http://en.wikipedia.org/wiki/Survival_bag


Cheers

Aaron

[Liamy77]

i havn't tried it yet personally but i have heard of people using Tyvek home wrap - Corvus has mentioned in one of his posts that if you wash it with detergent you can get rid of the Crinkle noise... i have been told that the tyvek tape makes a waterproof join if you wanted to make up a tube... there is a tyvek topic on this forum too.... when i can get hold of some i will put this all to the test myself - dunno about the snow cave yet though?!

[mikethepike]

I think that if i were to go snowcaving again in Tassie, I'd consider using a synthetic rather than a down sleeping bag. It will still get damp but would presumably retain a bit more of its insulating properties. Tyvek sounds promising but wouldn't the plastic type covers be substituting dampness from snowcave drip with dampness from body moisture though the latter is warmer I guess, at least initially.

[Liamy77]

It'd be nice to have a goretex bag cover/ bivi... $$

[jose]

I agree with Mikethepike about sleeping enclosed in plastic. I tried that once on a survival exercise, on a severe frosty night and, after only a few hours in a spacebag with many layers of clothes, I was very damp and cold. It would have taken longer to feel the damp if I had been in a sleeping bag, as you intend to be, so maybe it would be OK for one night but if you are planning several nights in the snow cave, your bag would be damp and cold to get into by the 2nd night. Breathable material would need to be used if you want to enclose yourself in a waterproof bag and stay dry otherwise I would stick to the plastic sheet over me which would enable moisture to escape at the edges.
Take the time to smooth the inner walls really well and you will not have the problem. Any snow melt will work its way down a smooth wall instead of dripping onto you. I have shared a snow dome with two others and the two sleeping against the wall had space blankets tucked under their sleep mats and folded over their sleeping bags on the wall sides. The one in the middle had no waterproof cover and none of our sleeping bags were wet.

[rucksack]

Liam77 has hit the nail on the head. I have two Goretex bivvy bags and I always take one of them when winter walking, snow camping, or xc skiing. No wet sleeping bag, dry clothes in the morning (just throw them inside the bivvy bag at night) and no worrying about rolling over during the night and unravelling that strategically placed bit of plastic. There is the cost, of course, there always is, but you will stay dry and warm. If you do a lot of winter walking or xc skiing, a waterproof, breathable bivvy bag is the way to go. Adds a few degrees to the sleeping bag, which can be entirely helpful too. If you get caught out, or just want to practice the delicate art of snow cave or igloo building, a bivvy bag solves a myriad of problems and prevents others from arising.

rucksack