View Full Version : Lets talk about goose down...
Is 800 fill goose down any warmer than 600 or any others, or vise-versa. i understand the size and weight differences. Is 850 fill for real? Any good goose down articles out there. a goose down 101???? I'm looking at the Big agnes Pomer Hoit SL 0° bag as a winter bag. Any one ever use there "overbags"? There are other big agnes bags i like and are cheaper, they are like 600 fill , and weigh more. This bag i need may be used in a southbound thru-hike starting in late Aug. FYI: i will be sleeping in a tent in the dead of winter, and have a BA, mummy, full size sleeping pad.
The number (eg. 600, 800 etc.) is the volume in cubic inches per ounce of down. So higher numbers suggest a bag that gives more warmth (loft) for a given weight of down fill. A bag made of 600-grade down can be just as warm as one made of 800-grade down... but in general it will be heavier and bulkier.
A bag made of 600-grade down can be just as warm as one made of 800-grade down... but in general it will be heavier and bulkier.just because it has the same temp rating doesn't mean the 650 bag is just as good though. mont bell super stretch bags in 650 have less volume with the 650 compared to the 800s. for their 15 degree super stretch.
the 650 has 22 oz fill = 14300 ci
the 800 has 20 oz fill = 16000 ci
143000/16000 = 89% volume in the 650 compared to the 800
so not all x degree bags are equal even from the same manufacturer.
Just look at 850 fill WM BAG'S and be done.:)
Hungarian goose down rocks !!!
Hey G-walk. Sounds like a great hike. We hiked together some between Harpers Ferry and 501 Shelter during your thru in '06. Did the I-81 hike to avoid the flooding, and rode the log skidder.
I found this podcast to be real educational in regard to down.
http://www.practicalbackpacking.com/audio/pbpodcast/PBP-28_Western-Mountaineering.mp3
Edit: Guess they won't allow a direct link. It just gets re-directed back here to Whiteblaze. It will work if you copy and paste the link into a new tab or window.
Wikisearch goose down sleeping bag. Lots of info from industry sites. You have to sort thru the testing labs vs the places that sell products to the "industry council" descriptions, standards, cleaning and testing methods.
From the external links. (Don't recall where the wheat is (as opposed to the chaff) but I found it at one time.)
http://www.idfl.com/articles/fillpower.asp
Note that the fill power rating for down is taken after an exacting laboratory process to completely dry out the down to 0% humidity. In the field, especially in the east or pacific northwest, conditions don't match the lab conditions. Also, whether a bag, quilt or garment, the hiker's body is infusing moisture into the down.
From test results that I have seen on the topic, any down rated above 725 in the laboratory dry condition, actually tests at about 725 at 50% humidity. Oddly, down that is rated at below 725 in the dry condition (say 600), still tests at 600 at 50% humidity.
The explanation of this apparent anomaly, is that low rated fill power down has more "structure" that can maintain loft when damp, whereas high fill power down is too gossamer to support the garment when damp.
So, I guess this should be taken into account when deciding value. Also, if one is into making your own gear, perhaps calculations for loft need to take fill power at field humidity into account instead of the lab ratings.
G-WALK,
Western Mountaineering's website will fill you in on down (not sales hype, either).
MAD777 had a good point - the stuff is measured in a lab, not real-world conditions. What matters is loft. higher-grade down will give you the same loft for less weight (under ideal conditions, anyway), or more loft for the same weight.