DAM vs. UQ?

[wisenber]

It's a shame you went with the DAM if you were concerned about moisture. I use a BA insulated air core that is synthetic and has a 4.1 R value. Even though I'm 6', I got he petite which is 66" for the weight savings. If I have to go to ground, I just put my pack under my feet. In my hammock, I don't need the full length.

That being said, I use both an UQ and a pad when it's below 30. I put the pad between my hammock and the UQ. I've used that combo with a peapod and -7 F was fine on the bottom. My No Sniveller and the pad had me warm at 15. If it looks to be colder than that, I bring my Huskie-Shepherd in my hammock for an extra 20 degrees.

[Just Jeff]

Do you recon that the 'cold to the bone' that we sometimes experience in cold humid conditions is due in part to our basic insulation being compromised by moisture penetration?

I guess it could be. It probably gets worse after several days of moist weather b/c you keep putting moisture into your quilts but, even though it's cold, the moisture can't evaporate as readily. This necessarily reduces its effectiveness. I know my quilts lost some loft on my FT trip b/c it was cool and moist every night for only a few days. Perked right back up when I finally took the time to dry them in the sun.

One thing I've always wondered about is how to dry the DAM's inside. There's only one valve so you can't create airflow. Maybe you could lay the DAM in the sun, on a slope, with the valve on the uphill side and open? Or you could just inflate/deflate several times in a dry environment. Otherwise, it seems that moisture would eventually build up and never escape.

But I just store mine with the valve open and it still works for me...haven't noticed a significant loss in warmth after maybe 30 nights on it, some in moist and some in dry conditions, so maybe this is all academic unless you're in prolonged cold/moist conditions.

[MacEntyre]

But I just store mine with the valve open...

That should work fine in a dry storage environment. If the vapor pressure of water inside the DAM is high, it will dry out on the inside, until it reaches equilibrium with the ambient air. It doesn't matter that the hole is small, or that there is no flow. It just takes time.

Since it takes time, the real problem is mold.

/engineer mode off/

[Youngblood]

...
One thing I've always wondered about is how to dry the DAM's inside. There's only one valve so you can't create airflow. ...

My Stephenson's DAM only has one valve but my Exped DAM has two. I think I recall reading somewhere where you could open both valves and use a hair drier (maybe on air only when it isn't humid?) to blow air in one of the valves to quickly circulate the air to dry it out quicker.

[HappyCamper]

My Stephenson's DAM only has one valve but my Exped DAM has two.

I was just going to say same thing. My down Exped 9 Deluxe has two valves. I never thought of the mold aspect. Good to know that I can try the hair dryer technique.

[Just Jeff]

Hrm...this made me go check my Downmat and it does have two valves. My thermarests have only one valve...guess that's where my brain fart came from. So the hair dryer trick sounds like a good plan for the Downmat and the heat should help kill any mold inside. That works good between trips...I wonder if anyone has actually experienced a significant drop in the insulation value of a DAM over a prolonged cold/damp trip. Anyone?

On a related note, I just got the REI version of the ProLite3 short and it says to blow into it to finish the inflation. Same deal...only one valve and blowing into it introduces moisture. But it's OCF inside so it shouldn't reduce the insulation at all. I guess it'll dry out eventually if I store it with the valve open, too.

[Big D]

I appreciate all of your responses. I had not considered the insulation in the mat getting wet from the humidity. The hair drier trick sounds like a great solution.

You guys are a wealth of information. Thanks for shortening my learning curve.

[Big D]

I actually bought a Syn mat. I found it for 35 bucks, so I got it. I had not considered the humidity affecting the insulation. I was thinking more of rolling fog and blowing rain.
It is nice to know how effective the insulation works for you. I have not used either of my new toys, so I look forward to experimenting with them soon.