Registered: 02/23/07
Posts: 1735
Loc: California (southern)
I bought what is essentially the same bag in 1983. I, too, have had similar experiences. Mine is still in use, although I usually carry lighter bags on backpacks. One, tough, durable, versatile bit of sleeping gear.
It's just a guess, but maybe it has to do with how densely they were stuffed to begin with. That is, if the older bags were stuffed "tighter," maybe any degradation would be less apparent. I suppose it's also possible that the newer down was processed more vigorously, perhaps to meet newer health standards (pure speculation). It could be time to wash the quilt, too, if it's never been done.
Registered: 10/30/03
Posts: 4963
Loc: Marina del Rey,CA
Fill power is based on an objective test using one oz. of down in a tube with a weight placed on top of it. I posted a link to a site with the testing procedure on it a long time ago; might still be here somewhere. Here is what's posted on Wikipedia- http://en.wikipedia.org/wiki/Fill_power There are links to a test lab at the bottom of the article-same one I linked to, I think.
The bottom line is that higher numbers mean more compressibility. How well an insulator works in a particular product will depend on construction. The idea is to create as much dead airspace between you and the outside air. A 650 jacket could be just as warm as an 800 jacket, just not a compressible and will weigh a bit more.
Edited by TomD (03/07/1007:44 PM)
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Don't get me started, you know how I get.
Tom D I think whats changed is there is no "weighted piston" anymore, no weight given nor diameter of cylinder stated, not weight per square inch remarked. I think they just fluff up an ounce of feathers and put it into a graduated cylinder with no weight and see how much room it takes up AND they do not then compress it down to see whether or not it actually takes up 0NE (1) unit of volume, also done under some un-stated amount of pressure/weight.
It is not obvious that there are in fact any standards or whether the "weighted piston" could be a piece of paper. So the stated fill power whether 700, 800, 850 or 900 has no meaning except price.
The marmot site says "if your down product says it is filled with 800 down, then it is filled with certified 800 fill power down"
Try searching on "down fill certifications" or "certification of down fill" on the Internet. The is NOTHING. You would think that a lab that certified down would be listed huh??? Jim
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These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.
Tom D I think whats changed is there is no "weighted piston" anymore, no weight given nor diameter of cylinder stated, not weight per square inch remarked. I think they just fluff up an ounce of feathers and put it into a graduated cylinder with no weight and see how much room it takes up AND they do not then compress it down to see whether or not it actually takes up 0NE (1) unit of volume, also done under some un-stated amount of pressure/weight.
It is not obvious that there are in fact any standards or whether the "weighted piston" could be a piece of paper. So the stated fill power whether 700, 800, 850 or 900 has no meaning except price.
Try searching on "down fill certifications" or "certification of down fill" on the Internet. The is NOTHING. You would think that a lab that certified down would be listed huh??? Jim
There are good internet researchers, and then not so good ones.
They have a comparison of the DIFFERENT WORLD STANDARDS for measuring down fill and and discussion on DIFFERENT SAMPLE PREPARATIONS that are used in different parts of the world.
Last year I downloaded a dozen documents on this from them.
I've worked as a researcher in science for 30 years before retirement, and learned the importance of trying and trying different search strategies to locate what you want. The key words YOU THINK should be good aren't necessarily the key words that ARE good.
Here are some words from their page on down and feather testing.
IDFL is the foremost leader in down and feather testing and quality assurance. IDFL performs testing in compliance with all major country standards as well as internal company standards. Content, Species, Fill Power, Average Feather Length, Cleanliness Tests (Oxygen, Turbitiy) and more are all performed at IDFL by an experienced and well trained staff. Feel free to contact us or see our Sample Submittal Form for a full listing of down and feather testing options. ...... =========================================================
Here is the page where they link to documents on testing and standards.
We have grouped our articles in the following categories:
* Cleanliness * Content Analysis * Fabric Tests * Fill Power * General Testing Information * News and Announcements * Quality Assurance * Standards and Labeling * Sterilization and Licensing Information * Tolerances
You may need to install Adobe Reader to view some of these files. It is free and easy to install.
After reading every article in the list from the above lab I learned a couple of things: "Down testing has changed in the last 10 years". Meaning that as we surmised, the new high loft down may just be the same old down measured differently. The USA system is cubic inches per ounce - with absolutely no reference to how it is measured, compression, weighted piston etc, except that it may be steamed and fluffed prior to testing. There are many international volume measurement satndards, like different shoe size standards, which may be compared using a table. NO WHERE IN ANY OF THEIR INFORMATION WAS THERE A DEFINITION OF HOW THE LOFT IS ACTUALLY MEASURED. so stuff it, the down I mean. Jim
Edited by Jimshaw (03/09/1008:29 PM)
_________________________
These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.
After reading every article in the list from the above lab I learned a couple of things: "Down testing has changed in the last 10 years". Meaning that as we surmised, the new high loft down may just be the same old down measured differently. The USA system is cubic inches per ounce - with absolutely no reference to how it is measured, compression, weighted piston etc, except that it may be steamed and fluffed prior to testing. There are many international volume measurement satndards, like different shoe size standards, which may be compared using a table. NO WHERE IN ANY OF THEIR INFORMATION WAS THERE A DEFINITION OF HOW THE LOFT IS ACTUALLY MEASURED. so stuff it, the down I mean. Jim
Did you read the document on "Test names and Standards" and did you understand it? Did you see the standard below: "Fill Power (Steam Conditioning) IDFB – 10-B"
Did you notice the lack of public access to the many detailed standards that they have?
You might be able to call them and get a copy. It could be something that they sell as a product. There is no real reason why they should freely publish this. The US FTC has done a poor job of standards control in many consumer areas, and private organizations like ASTM step in to fill that void, and to eliminate the need for the more federal regulation - a big selling point in getting corporations to join ASTM.
You pay to get access to ASTM standards, as a general rule. Private industry does things like this.
Quote:
Test Names & Standards List INTERNATIONAL DOWN AND FEATHER LABORATORY AND INSTITUTE Page 1 9 January 2008
Test Name Standard(s) Content Analysis (Composition) ASTM D 4524, IDFB-3, JIS 6.6, EN 1162 Oxygen Number IDFB – 7, JIS 6.6, EN1162 Turbidity IDFB – 11, JIS 6.5, EN1164 Species Identification IDFB – 12 Fill Power (Steam Conditioning) IDFB – 10-B
You probably glossed over the document "Fill Power Evaluation of Conditioning Methods". It says the following, in part, ...
Quote:
Many different measuring systems and cylinders exist to measure fill power:
• IDFB/Lorch mm/30g • IDFB/Lorch cubic inches per ounce • EN 12130 mm/20g or cm3/g • USA Cylinder cubic inches per ounce • JIS Cylinder cm/30g • China GBT Cylinder cm/30g
All of the above systems can normally be converted to the approximate value of another system with standard factor tables.
However, the most critical part of fill power testing is the conditioning method.Any of the conditioning methods can be used with any of the cylinders and measuring systems. Most countries and regions specify which conditioning method should be used with which cylinder.
So they are telling you, generally, that one uses a SPECIFIC CYLINDER and weight. The standards for each test will specify the cylinder in detail.
So, it appears as if once again, you are stuck with needing access to standards .... which may or may not be free. And, you may need specialized knowledge to figure out how to obtain them.
Not unusual in engineering. You are taking on a specialized knowledge problem and trying to stuff it into a simple Google search.
At least we can see the differences in the approach of a research amateur and a retired professional.
I won't take the trouble to Google the names of the different test cylinders to see if you can get the details free or not. If you are REALLY interested, you can do that.
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