Mar 26, 2014 at 1:07 pm #1314860
Hello, I recently scored a 7 lb down comforter for $2 at Goodwill. I figure there's at least a 3-4 pounds of down inside I can harvest for some MYOG projects.
How can I test the fill power of the down at home (preferably using "regular" items from home, if possible)?
I searched online and on BPL and found bits of info here and there, but I'm looking for an detailed accepted method to estimate fill power to at least the nearest 100 (500 vs 600 fill).
If there is a forum thread I'm missing please post it.
Thanks!Mar 26, 2014 at 2:35 pm #2086420
@sharaldsLocale: Gallatin Range
Western Mountaineering describes the testing process in medium detail here:Mar 27, 2014 at 4:09 am #2086594
@jamesdmarcoLocale: Finger Lakes
Atually, testing down fill is fairly easy. Weigh out as accuratly as possible a 1ounce sample. Shake it up and see where it settles. There are certain set sized diameter tubes that are used, I think it was 3.25"(Note: looked it up, below) in diameter. The volume is the fill power. If it takes up 500ci, then it is 500fp.
Basically, loft is measured by placing a sample in a cylinder with a weight and checking how far the weight descends. From wikopedea:
lofting power of 400–450 is considered medium quality, 500-550 is considered good, 550–750 is considered very good, and 750+ is considered excellent.
US 2000 norm: cylinder diameter: 241 mm conditioning: steaming +3 to 5 days in a screen box compression cylinder: non-mechanized cylinder of 68,3 grams. Mass of the sample: 1 oz = 28,4 grams.
EN norm: cylinder diameter: 284mm, conditioning: tumble dry +2–5 days in a screen box compression cylinder: Lorch machine = mechanized cylinder weighing 94,25 grams, Mass of the sample:30 gramsMar 27, 2014 at 6:27 pm #2086855
Thank you both for the info.
Last night I messed around and conducted a very makeshift test:
1. I marked on my bearvault can increments of 100 cubic inches up to 700.
2. I measured 1 oz of down (straight from the comforter, no conditioning) and placed it inside, screwed the lid on and shook it up. The down nearly filled the can after letting it sit for a bit (~650 cu in).
3. I cut a circular piece of cardboard (~30 gram) and placed it on the down. The down compacted to around 500 cu in. The weight of the cardboard is not in sync with Standard test for multiple reasons, one of them being my "cylinder" is much wider and therefore applies a different pressure to the down.
4. When I removed the weight the down remained wedged in the can.
My big question is: What role does the weight play determining the fill power?
Its my understanding that "A piston weighted to 68.4 grams is placed on top of the down and when it comes to rest the volume of the down is measured in cubic inches" (Western Mountaineering). How much is the down compressed by this weight? From my test I conclude that the weight has a significant effect on what the reported fill power would be.
Do you know why the specific weight of 68.3 grams is used?
ThanksMar 27, 2014 at 6:42 pm #2086859
How much is the down compressed by this weight?
Read again the last two paragraphs posted by James .Mar 27, 2014 at 9:15 pm #2086902
Let me clarify my question: I was wanting to know a percentage (or some quantity) of how much the down is compressed during a test. Example: 1 oz of down takes up 1200 cu in before the weight is applied and it takes up 600 cu in after the weight is applied (50% loss).
In your first paragraph about testing down fill, is a weight applied to the down? The link from Standard Fiber does not mention a weight. "Maximum loft" would be achieved with no weight, right.
Are fill power and loft (or lofting power) the same thing? If different, how so?
Thanks!Mar 28, 2014 at 2:15 am #2086937
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
> I was wanting to know a percentage (or some quantity) of how much the down is
> compressed during a test. Example: 1 oz of down takes up 1200 cu in before the weight
> is applied
Two problems here
* There is NO standard for measuring the volume before compression, and I doubt you could ever get consistent results for that idea either.
* You MUST condition the down before measuring it if you want to relate your results to anyone else's.
So there is no answer to your Q about percent compression.
CheersMar 28, 2014 at 4:40 am #2086945
@jamesdmarcoLocale: Finger Lakes
I don't know that there IS some standard number for applying to a down sample.
1) Static electricity
3) Age of sample
4) Type of cleaning, (wether cleaned at all)
5) Bleaching agents used for cleaning (bleach will remove plume barbs)
6) Organics left over from processing
7) Differences between samples
and so on…
Each item will add maybe a 20 ci difference, with some adding more than others. Some are spec'ed to maintain controll's and others are not. There are more(turbidity and oxygenation…likely beyond scope of a home tester.) Higher qualty down fills will compress MORE than low quality fills, hence the importance of using a standard sized glass tube. The methode described with your bear vault would be good, except the flotation area will change vs a standard test. The second thing is that you need two numbers, generally 24 hours apart, though there is some tollerance of unknown time. Example: 12+ hours could be rounded to a day…12- hours could not.
A lot of things go on to achieve the best numbers and worst numbers depending on who is doing the testing. Off hand, I would say you are lucky to get within 200ci of a standard test.
Usually, comforters with "down" fill as opposed to "feather" fill are around 450-550. Old pillows are usually "feather" fill which means 50% of the fill is chopped or unchopped feathers. Feathers have a "stalk". Down does not.
So, IFF you stick to the standards, you *might* come within 100fp. Using your bear ball without standard drying/washing/humidity you will be within 200-300fp.
Anyway, yes, a maximum lofting would be achieved with no weight. Fill power and loft generally apply to the same thing. Example: 600FP (Fill Power) down will give you a 2" loft. FP is a cubic measurment of volume. Loft is the result of X amount of Y FP down in a known space, Z or roughly a linear measument. Not to worry, we know what you mean with either term by the context. (I HATE english, it lets this happen.)
The terms "down" and "feather" are often misused. The US simply say the majority. So, >50% is DOWN, and <50% is FEATHER. But, I am not sure what they consider "down." I do not consider anything with a stalk, down. Even the tiny little feathers that will occasionally pop through a bag. They *might* consider the downy bottom of a feather down. A BIG difference.
So, often this is where integrity comes in. I would trust the measurments done by WM, FF, or Nunatak. I would not trust Coleman, or some others that "use" down without testing. Producers rarely test more than one or two samples. More if they have integrity, meaning their supplies are likely to be more varied, less so if they really consider feathers/down a byproduct.Mar 28, 2014 at 3:08 pm #2087148
@anthonyjhuhnLocale: Mid West
If you used a 57.4g weight in your BV500 you would at least have replicated the us2000 test pressure
EDIT: The weight of 68.3g is over an area of 456.17cm2…. therefore to get the same pressure over the BV500's 383.60cm2 you need a weight of 57.4. as Pressure is force/area.
The weight isn't really that important, its the pressure that is important
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