Companion forum thread to: Episode 46 | Water-resistant Down
Andrew chats with the down experts at the IDFL Laboratory and Institute about water-resistant down.
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Companion forum thread to: Episode 46 | Water-resistant Down
Andrew chats with the down experts at the IDFL Laboratory and Institute about water-resistant down.
Going to bump this as it’s a pretty interesting discussion without getting into proprietary trade secrets (different manufacturers offerings) of down.
Just remember: the Europeans won’t have anything to do with IDFL, because they think the IDFL figures are a bit of a con. You can never get close to those figures in the field.
Cheers
A few things in this podcast were new to me.
– Body heat and moisture helps down loft up and insulate better. That’s why down sleeping bags and quilts are puffier after sleeping in them overnight, not just because they decompressed a little more.
– There are no regulatory requirements for the “water repellent” part of DWR-treated down. But most manufacturers pay to test water repellency on a scale of roughly 15 to 1,000, where 15-30 is untreated down. I can’t recall seeing that number for any down product. I also don’t know if in real life 1,000 is 66 times better than 15.
– Washing improperly is the #1 killer of down. Follow the label instructions. Don’t substitute detergents, use hot water, or dry with heat. I postpone washing down stuff as long as possible.
– Down is a byproduct of raising geese and ducks for meat. If down doesn’t go into a sleeping bag or other product, it goes into the trash. And down has been re-used for new garments for hundreds of years.
Thanks for the enlightenment.
— Rex
What’s wrong with regular old goose down, untreated? It’s worked for a hundred years. I don’t think WM or FF even bothers with the stuff. And then there’s this question—does the chemical treatment out gas into the sleeper’s lungs???
Water-resistant down is still early in its development cycle, at solution seeking a problem.
I don’t think WM or FF even bothers with the stuff.
WM is crystal clear about it:
We have found in our own testing that the performance enhancements of hydrophobic treatments on high quality down are widely overstated. High quality untreated down already has naturally water repellant oils on it left by the geese (makes sense since geese spend a lot of time in water). These oils help repel water and keep down lofted. More importantly is that these oils last indefinitely. Hydrophobic treatments wash out like a DWR and remove the natural oils during the application process. Because of this, and the water resistant capability of our shell fabrics, we feel that hydrophobic down does not provide a considerable impact on performance and could actually inhibit performance over the lifetime of our products.
Amen Todd T—end of story.
If the oil on down lasts indefinitely why do geese (and other birds) have to preen themselves, applying oil from the uropygial gland?
Chris…..I believe this site will help you understand the preening process and why it is necessary.
I know why birds preen, for waterfowl one of the reasons is thought be that it helps waterproofing. My question is over the assertion that natural oils last indefinitely.
A solution seeking a problem? Not quite, just marketing seeking something that sounds good in a press release even if meaningless in reality.

Cheers
Having washed down bags in the tub, it can take quite a bit to get the water throughout.
Having washed down bags in the tub, it can take quite a bit to get the water throughout.
I was going to make the same comment. And in the subject podcast, the IDFL guy spoke of a test where they had to shake the down in a jar of water for about a half-hour (IIRC) to reach saturation. A half-hour!? And we need to augment its water resistance?
It’s all marketing.
Haven’t used these guys yet, but intend to when I need to wash my premium down gear
https://www.cleanwithtersus.com/collections/cleaning/products/insulated-down-jacket
Get out the pitch forks ;0)
popcornman
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