RE: Down Bag weigh gain

Nelson,
	Hmmm....18oz is a lot, even given the penchant for manufacturers to always err on the low side with weights. Many bags are listed with two weights, Total weight and Fill weight. You might have the wrong number to compare?
	Yes. Over time a bag will pick up oils and fine dust. This rarely adds more than a half ounce, though. Shell materials over the past 30-40 years or so have been very finely woven. 'Corse this depends on where you hike. This lets them resist everything except the very fine dust. On one of my trips last year, I weighed my bag before and after and got only a 1.375oz(1-3/8oz) difference after two weeks. But I suspect this was due to moisture more than anything, since the bag felt damp and lost almost a quarter it's normal (clean) loft. I did not try simply drying it though... Even though it lost much of it's loft, it still worked OK, keeping my feet and legs warm... (Smaller air pockets are more efficient than larger air pockets as insulators, so I suspect it might have lost 25% of loft but stayed around 85% of full warmth.)
	Anyway, just a thought . . .
		jdm  
	
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Nelson
Sent: Thursday, February 28, 2013 5:24 PM
To: [email protected]
Subject: [BackpackingLight] Down Bag weigh gain

I have a TNF down 20 degree bag("Orion") about 15 years old. Have washed it twice, most recently 3-4 months ago. Curious, I weighed it and found it was about 18 ounces heavier than the original, listed weight; this was the first time I had ever weighed it. I have always worn clothes while using it.Thinking it might be moisture, I put it in a dryer it a week ago for about 45 minutes; the weight was unchanged. Can't quite figure this out.