AnAvoiding wet down

Posted by: C3PHA5

AnAvoiding wet down - 09/20/12 12:53 PM

Any advice on how to avoid ending up with a damp down bag would be nice. Im not planning to use it in a rain storm or anything,( although thats always a possibility) but is humidity going to be a big factor? Any pointers on times where this is an issue or any other advice would be greatly appreciated.
Posted by: Pika

Re: AnAvoiding wet down - 09/20/12 02:29 PM

You can minimize the effects of humidity on down by 1) squeezing all of the air out of the bag as soon as you get out of it in the morning. This gets rid of whatever water vapor that has accumulated in the air spaces from your overnight perspiration; and 2) Airing and sunning the bag whenever you get a chance during the day. Hot sun will drive out a lot of the moisture that remains after you give your bag it's morning hug. Keeping the bag away from rain and wet tent floors is always a good idea too. It is easier to keep a down bag dry than it is to dry one after it gets wet.
Posted by: lori

Re: AnAvoiding wet down - 09/20/12 05:03 PM

Hand washing my down quilt alleviated any anxiety about wetting the down to the degree that it clumps and loses all loft. It's actually hard to do.

I would worry about down in winter more, when the frost point can move inside the bag shell.

it depends on where you go too, and for how long. A Few nights in a relatively dry climate are nothing. In very humid places, where drying in the sun doesn't do much good, it's harder.
Posted by: OregonMouse

Re: AnAvoiding wet down - 09/20/12 07:35 PM

When you do wash a down item, be sure to replenish the DWR finish on the outside afterwards. The Western Mountaineering website has excellent instructions for laundering down. As already mentioned, when you try to wash a down item, you'll find out how resistant it is to getting soaked.

Note that, despite some claims by the synthetic insulation industry, wet synthetic insulation is no warmer than wet down insulation. (Been there, done that. blush ) Regardless of the type of insulation, you must keep it dry.

In the pack: use dry bags (not stuff sacks) or tightly closed mylar (turkey roasting) bags or line your pack with a 2-mil plastic bag (trash compactor bag--be sure they're unscented) or contractor trash bag or other waterproof liner. Test the liner periodically and replace if needed. Check daily for small holes and use your duct tape. Pack covers will NOT keep your pack contents dry--heavy run runs down your back and into the pack, and if you slip and fall during a dicey stream ford (again, been there, done that blush) it won't keep the water out of your pack.

On the trail--don't wear your insulating jacket while actively hiking; use a thinner mid layer instead (for me, a wind shirt and baselayer top, plus cap and gloves, are sufficient down into the teens F). The idea is not to get chilled, but to at all costs avoid sweating into your insulation. The insulating jacket is to keep you warm when you stop hiking. If it's raining, keep it under your rain jacket.

When camping in the rain, set up your shelter first (it should be accessible without having to expose your pack contents to the rain) when you stop, and take it down last when you break camp. Do all your unpacking and packing under the shelter.

Even here in the Pacific NW during the rainy season, we usually have a midday "sun break." Take advantage of these to air out your tent and sleeping bag. Even 15 minutes helps!

When it's below freezing, a vapor barrier inside your sleeping bag really helps keep the moisture from your body from condensing--and possibly freezing--on the inside of the outer shell of your sleeping bag. Just remember not to wear your insulating clothing inside the vapor barrier, because it will be damp inside. Wear only your base layer (which should be a fabric that doesn't absorb moisture) inside the base layer. Different folks have different reactions to vapor barriers. I do fine as long as the outside air temperature is below freezing. Others have to get into much colder temperatures before the air inside the vapor barrier ceases to become a sauna.

This new dry down stuff sounds interesting but (being a bit of a skeptic and not having much $ to spend at this point) I plan to wait a year or two to find out if it's helpful enough to be worth the extra $$$. It hasn't been around long enough to get widely used in Pacific NW winters, which IMHO are a pretty good test of moisture resistance! I hope that if anyone here tries it, they'll report back!
Posted by: TomD

Re: AnAvoiding wet down - 09/22/12 03:31 AM

Try not to sweat in the bag. If you are sweating, you are too warm. Wear a base layer if it's really cold, but again, open the bag if you find yourself overheating. To keep moisture off the outside of the bag, if it's not made of Goretex, Pertex or eVent, a light bivy cover like a BD Winter Bivy will work. The BD is no longer made, but someone must have something similar. Don't wrap it in a space blanket or anything like that as you will just trap moist air next to the bag,
Posted by: C3PHA5

Re: AnAvoiding wet down - 09/22/12 08:08 AM

Thanks everyone for your advice, you have helped alleviate some of my concerns and given me some things to think about while on the trail.
Posted by: OregonMouse

Re: AnAvoiding wet down - 09/22/12 05:46 PM

My one experience with a light bivy cover involved slipperiness (from the silnylon bottom) and internal condensation. The latter was probably because I toss and turn a lot, so the silnylon bottom of the bivy ended up mostly on top, where the water-repellant/breathable half is supposed to be! With some bivies, you can eliminate this problem by staking it down, but you can't do that inside a tent with a floor.

Makers of lightweight bivies (really sleeping bag covers, not stand-alone bivies) include Mountain Laurel Designs, Titanium Goat, Katabatic Gear, and probably a few others that I don't remember. The above firms will alter the bivy to your specifications (for an additional charge).

A bivy is one of the easiest "make it yourself" projects (it's basically just a bag with a zipper), if you have at least a minimal talent in that direction. If I were going to make one, I'd make it big enough so I can put my thick sleeping pad inside, too, and I'd make the whole thing out of DWR nylon (such as Momentum) instead of a silnylon bottom so it wouldn't matter if the bottom ended up on top. Your mileage, of course, may vary!

Most modern sleeping bags, at least the higher quality ones, have a good enough DWR (durable water repellent) outer shell that the bivy/sleeping bag cover isn't necessary unless you're sleeping under a small tarp. Mine has been "sprinkled" on several times when there was bad condensation in my tent and my dog started his full-body-tail-wag routine before I could wipe down the walls. I just shook it off my sleeping bag and nothing soaked in.