Be careful with down Fill power

6:02 p.m. on May 20, 2011 (EDT)
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135 forum posts

I read a lot about procedures concerning fill power test. So i decided to share some of what i've discovered with you. Everything here comes from the IDFL website or emails exchange with down garments and sleeping bags manufacturers. I sent emails to manufacturers and some of them where very cooperative some not at all. But that's not the point here.

Fill power vs Fill volume :

Many people mistaken and believe  that powerfill is defined as the volume occupied by 1 oz of down. It's not true. This is the loft or the fill volume.

So let's discuss the definition of fill power  : it is the volume occupied by a down sample (usually 30 gr or 1 oz) subject to a certain pressure  at a certain temperature (20 Celsius) and hygrometry (65%). This pressure is due to a mass that's put down the sample. The diameter of the mass equals the diameter of the cylinder where the sample sits. We'll call the compression cylinder.

Now what's the difference between US and EU powerfill :

US 2000 norm :

  1. cylinder  diameter : 241 mm
  2. -conditionning : steaming+3 to 5 days in a sreen box
  3. compression cylinder : non-mechanized cylonder of68,3 grams.
  4. Mass of the sample : 1 oz=28,4 grams.

EN norm :

  1. cynlinder diameter : 284mm,
  2. conditionning : tumble dry +2-5 days in a screen box
  3. compression cylinder : Lorch machine= mechanized cylinder  weighing 94,25 grams,
  4. Mass of the sample :30 grams

Now there is no exact conversion table between those two. But there exist some approximation. The usual one is that US FP=EU FP+50. Which is quite not true.

 But there is an approximate conversion table for the cylinder used. Here we suppose that the methods of conditionning is tumble drying :

For down with a FP exceeding 700 cuin, there is an approximate difference of 4,3%.  if it is between 600 and 700 cuin the difference is about 2,5 % and almost 0 for low quality down.

So a 800 EU FP down is about 840 US FP down.

Since 2005-2006 : the US norm started to use the steaming conditionning which (non artificially) improve the FP by about 50 cuin. So that's why 900 FP down suddenly appeared. Actually it's still a 850 US FP from before 2006 and manufacturer tried to trick us. 

 That's it for today, To be continued.

9:41 p.m. on May 23, 2011 (EDT)
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1,935 forum posts

great insight Brumo on the cylinder test's..But why does the US use steaming before tumbling? Is it to just create more Loft properties?Smaller cylinder diameter as well which means less volume...thats good to know..Look forward to your next installment..Welcome to trailspace as well...

4:40 p.m. on May 29, 2011 (EDT)
76 reviewer rep
135 forum posts

Thank you.

Steaming conditionning is used so that test results are more consistent. The standard deviation is lower with steaming conditionning.

It doesn't improve the filling artificially though. It reveal the full potential of the down. But you'll hardly reach this in real condition. My point is that you have to be carefull with the new results as it give a higher FP value. So you can claim 850 for something that was rated 800 before 2006. Fortunately serious brand like Valandré, WM, FF Triplezero, don't play that game. What is important for the down you use is the maturity of the bird, how he is raised, how down is harversted and processed. From what I learned, for durability maturity is the key factor. Barbes and flakes are stronger bigger and more flexible. Unfortunately there is few informations available for those topics on brand websites. So you better ask the company directly, or check where is their down coming from (the producer not the country). 

7:53 p.m. on May 29, 2011 (EDT)
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Down-filled products from Valandre (bags, jackets, etc.) are  hideously expensive.

Good Grief !!!


 ~ r2 ~

8:05 p.m. on May 29, 2011 (EDT)
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613 forum posts

The price of a given item of gear is directly related to it's performance and I consider Valandre to be fairly priced and the finest sleeping bags, in their Shocking Blue and Bloody Mary models, that I have seen or used in over 46 years of sleeping in cold and remote, rugged wilderness. These bags are not really intended for the recreational backpacker in settled regions where SAR is close by and cellphone towers are everywhere as well as the climate is mild; they are for nights when the temperature is -20*F and you are far away from any assistance should you become hypothermic.

After owning and using a custom-made original Marmot Mtn. expedition bag from the early Grand Junction days when they still hotcut every piece of fabric, a Feathered Friends ultralight bag I had them make me in 1989 for sheep hunting and a WM Alpenlite, a fine bag but too snug for my large shoulders plus a full custom bag by Integral Designs, that will keep me cozy at -40, I will flatly state that  the BEST sleeping bag I have ever owned is my Valandre and I wish I had had this since I was a youngun spending 6+ months a year, mostly alone, in the BC mountains.

If, I bought another down parka and I have and have worn out some superb ones, I would buy ONLY a Valandre or a Westcomb, the price reflects the functional quality and one does not worry about a couple of hundred bucks when it is -40 and you still have over five miles to go on snowshoes before you get home.

8:42 p.m. on May 29, 2011 (EDT)
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Good testimonial, Dewey.

Perhaps (?) if I look at the numbers in Euros (smaller) it won't seem to cost as much.

~ r2 ~

9:39 p.m. on May 29, 2011 (EDT)
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613 forum posts

Very simply, if I were a recreational backpacker in a settled region of the USA, I would not bother to buy a Valandre as there is no need for such a bag. Why spend the coin when you do not need and cannot use the functional qualities inherent in gear of this type?

But, for those who are into serious winter campiing in more remote areas of North America, or climbing or hunting in colder regions, these bags actually give a level of value that is outstanding and are worth the price, in any currency.

4:05 a.m. on May 30, 2011 (EDT)
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135 forum posts

Valandré is expensive, because the US dollar is artificicially low to increase US export. In Europe their price are not that high. And I have to say that they are amongst the only down gear manufacturer from which you can track the source of their down and be sure of what you get. 

Down is great because it is durable, eco friendly and last a life time if it is mature and carefully processed. So you may pay a lot for a high quality down product but it's never a bad investement. The main point here is to have a very durable product that suits your needs. It goes again the usual planned obsolescence trend that we live in for decades now. People buy cars and computers every 2 our 4 years. Do they need it, is it worth the price. No. With high end down product coming from serious manufacturers you have a long lasting product that can even save your life in extreme situation.

The purpose of this kind of forum is to give useful informations so that people can make the right decision. You may pay extra money but if you know exactly what you buy, I think it's ok.

4:56 a.m. on May 30, 2011 (EDT)
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135 forum posts

I'll give more info about conditionning. I think it is usefull because it also gives hints to maintain the loft of our sleeping bags or down garments.

As I said labs use different conditionning methods. The reason being that after a long travel, the down loose some of its initial loft. For example, the producer is Canada but the lab is in Ontario let say. 

before 2006, all labs used Tumble drying and then let the down in a screen box for some days. Now for the US and Japanese test they are steamed. This steaming procedure add moisture. Moisture is important for the loft. From what I understood you need a certain amount of moisture to reach the full potentiel of the down. Too dry is not good, too wet is not good neither.

The other think is that up a certain point, the more days spent in the screening box the better the test is. After 5 days you get a better result than after 3 days. The minimum period is 2 days. But you don't know if the 850 was reach after 2 3 or 5 days.

This is not really important as you know now what this number is really about. But what is interesting is how to apply this to the field.

Before going back packing you can tumble dry your sleeping bag or down garment and add a wet tissue inside the dryer to add moisture. Also Loft increase when you use it because of your perspiration and heat. 

Finally never dry clean your down product (like Canada goose suggest). The chemical product will dissolve the precious oil present in the flakes. Your down will consequently be less lively and loose its loft and its durability. 

7:23 a.m. on May 30, 2011 (EDT)
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I have learned a great deal from you, Brumo ... and, you also, Dewey.

Thank you, both.

~ r2 ~

3:24 p.m. on May 30, 2011 (EDT)
76 reviewer rep
135 forum posts

Thanks Robert. 

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