[pct-l] Beeping Slags

["David B. Stockton" <davstock@tiac.net>]

>>
I am considering trying an ultra-light down sleeping bag instead of my 
North Face Climber 3D, but am concerned with moisture, since I use a tarp 
when backpacking.  Does anyone know of a source that uses some kind of 
"dry-loft" coating on a down bag, or is this a bad idea because of moisture 
buildup in the down?
<<

Personally, I can't see any reason to have any coating or GoreTex or 
whatever on a sleeping bag, except to prevent your hot cocoa from soaking 
it if you spill (not a valid reason for this discussion).  One's PRIMARY 
goal is get moisture out of it at all times.  If one is concerned about 
snow cave drips, use a bivvy sack.

All the various coatings, etc, do is slow down the vapor transport out of 
the bag, especially that of one's insensible perspiration, which is 
considerable.  Using a GoreTex bag even in dry conditions without special 
drying efforts (read: "No walking") during the day soon results in a cold 
bag.  (I used a GoreTex down bag for 350 mi of PCT in '94)

A tarp, in my opinion, just helps, because it promotes airflow, which will 
help pull the moisture out of the bag.  Even under conditions when the 
flowing air is very moist, such as in a heavy downpour in a 
properly-pitched tarp, one's body heat will help drive out the moisture.

By pitching a tarp before pulling my homemade Hollofill II bag with its 
plain ripstop shell out of its waterproof sack, I can prevent solid water 
from hitting the bag, and it will stay warmer night after night.

-- Dave

David B. Stockton
davstock@tiac.net


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