Bivy as stuff sack for down quilt?

Hi John,

It did this on a few trips but with a Waterproof bivy and it worked Ok.

Cheers,

The bivy would have to be completely waterproof and seam-sealed to keep your quilt dry. Of course then it will be wet inside from condensation!

not only that, you'll need the bivy to be as dry as possible when packing, inside and out. Even if the bivy is waterproof, compression would force any remaining humidity in. Waterproofness is always a relative term.

I use a stuff sack as a bivy for my quilt.

Actually, I never use stuff sacks, but I use my pack liner (compactor or nylofume bag)as a lower body bivy over my sleeping bag. It works well w/ my 9 x 7 foot tarp to keep spray off my lower left and give me a little more flexibility to move around a bit under the tarp w/out fear of getting my down wet. GL!

I have been storing my quilt in my bivy for years now. I get out of the bivy, pull the mat, then zip up the bivy. I loosely roll it up and put it in the pack. In real wet areas or stream crossing I will pack everything up in a bag as well. The issue is that the water will soak out your quilt if it enters your pack in a major way. But this system keeps your quilt clean, eliminates two stuff sacks and allows a loose pack in pack with will allow the quilt to fill the nooks and crannies among your gear. But completely waterproof, at least my bivy is not.

My bivy is the stuff sack for my quilt when it's not raining. When it's raining, they go into my over sized clothing stuff sack, and all that goes into a plastic bag.

I don't really use the bivy as a stuff sack for water protection, but for convenience. The downside is that I often get condensation in the floor of the bivy, so I have to take time at some point to dry it out unless I can hike while airing it out.

The MLD Superlight Bivy is not a waterproof bivy, therefore, to specifically address your question: The MLD Superlight Bivy may not keep your bag/quilt dry if your backpack goes into a stream or if you encounter hours of rain.

That is what a dry bag is for. Be it a dedicated dry bag or one of the plastic trash compactor bags (just make sure you learn how to close it good enough to prevent water entering it, should your backpack go under while crossing a river) that people like to use these days.

As a SUL/XUL hiker, a dedicated 15 gram (half an ounce) bonded cuben fiber stuff sack that is 100% devoted to keep my sleeping bag and down jacket dry – no matter what – is 15 grams worth having. Your sleeping bag is arguably the most important item in a SUL/XUL backpack, do what you have to in order to allow it to do its job when it comes time to needing it.

Where is the best place to purchase a cuben dry bag for my quilt?

http://www.mountainlaureldesigns.com/shop/product_info.php?cPath=48&products_id=148

http://www.zpacks.com/accessories/dry_bags.shtml

+1 on the cuben dry bag. Very good items….keeping that down bag dry is super important on a lot of trips.

You can go with light cuben (0.5oz or 0.7oz) and it'll do pretty well for a while….maybe 40-50 days. Eventually the cuben near the roll top will start to delaminate due the stresses of rolling and squeezing. I'm using a 1.2oz cuben dry sack now that should last for years….slightly heavier at ~20g vs about 13g for my old one (Granite Gear Uberlight CTF3, 13L).