Sleeping bag shell materials

[George in VA]

Hi All,


As someone who hasn't purchased gear since the mid 1990's and has been recently doing heavy research here on WhiteBlaze, I'm curious about something -- I've looked through dozens of posts on sleeping bags and I've never seen any advice on water resistant shell materials.

As hiking in the rain, setting up a tent in the rain, sleeping in the rain, breaking camp in the rain, etc is a reality on a long AT hike; I'm wondering about keeping a down bag dry if the side or footbox gets pressed up against the tent wall all night or there is a leak. -- Do the new bags all use some sort of water repellant coating? Is there some new shell material that is so ubiquitous that nobody even thinks about sleeping bags getting wet anymore? Or do thru-hikers just get in the habit of wrapping the footbox in their rain jacket and staying centered on their air matress to stay dry?

I've seen posts where someone opts for a bag with a different type of shell material but no discussion as to why it was purchased or what some of the good shell materials are. I'm just curious, talk about shell materials was all the rage back in the day and I'd like to know what to look for.


Thanks for helping me get back up to speed,

George

[Snowleopard]

You still have to worry about keeping your sleeping bag dry, but the new stuff is better, more resistant to accidents (spills). The fabric in a sleeping bag needs to be breathable or your insulation wets out from condensation. I always air out my bag in the sun whenever I can to keep it dry.

The term to look for is DWR:

DWR is a fabric treatment, DWR stands for Durable, Water, Resistant. This durable water resistant treatment coats the fibers of the fabric
with a hydrophobic finish, that causes water to bead up and roll off of the fabric. The DWR treatment does not close off the tiny
openings between the fibers of the fabric, in turn keeping the fabric breathable. http://www.titaniumgoat.com/DWR.html

Goretex and Event also use a DWR plus a waterproof membrane, but many light nylons have a DWR without the membrane.

There have been advances since 15 years ago. There are a number of very breathable water resistant, not waterproof fabrics. My new winter bag uses a Pertex Quantum Endurance shell which is pretty remarkable stuff -- throw water at it and it splashes off or beads up. Feathered Friends (high end sleeping bags) use Epic or Event fabric; Event is waterproof, similar to Goretex but more breathable, Epic is water resistant and breathable. You wouldn't want to sleep out in the rain in any of these with no other protection. For waterproof/breathable Event is the way to go except for price ($$$). Nowadays I wouldn't consider a Goretex shell and would prefer a good water resistant breathable fabric, followed by Event (maybe Event first for really wet conditions)

If you have an old down sleeping bag that is still good, use it. My summer bag (old but good) has plain old nylon for the shell fabric; all the fancy stuff was too expensive for me when I bought it and it works fine. If you want more protection, use a light bivy sack.

[George in VA]

Thanks Snowleopard. I appreciate the information and the link. I now understand what manufacturers are talking about when comparing finishes to Event or Epic. Or when someone is talking about Membrain and how it performs compared to base DWR technology. Thanks!

George

[fiddlehead]

The lighter and less waterproof it is, the more it breathes.
I use a tent or tarp to keep the rain or dew off my bag and use the lightest weight, most breathable fabric for the outside that i can.
Just my 2 cents.