Hi everyone,
When buying down products nowadays, is hydrophobic down considered a 'must have'?

I don't generally think so but maybe that's me. I've never knackered a down item whether it was or wasn't.

In short, I’d say no!

Nice to have but not essential

How often does your bag get damp or wet? Although I do believe the coating helps with lofting

If I were looking at two bags of similar specs and one was hydrophobic and one wasn’t, the hydrophobic would sway me. My current bag doesn’t have it and i wouldn’t change my bag because it didn’t

There, I think that’s cleared the matter up?!

PHD reckon that hydrophobic down performs less well than untreated down.

https://www.phdesigns.co.uk/down-gear-in-use

Having once-upon-a-time got a synthetic bag wet I can tell you that keeping water away from any sleeping bag whatever the filling is important.

If you're going to treat yourself to a PHD, and are concerned re damp, get Ultrashell outer (or whatever latest equiv is) - extra 40g and a couple of quid.

Most fabrics used by the better manufacturers are reasonably water resistant to a point. I've spilt small amounts of water on my quilt and having immediately wiped it off there's been no noticeable wetting of the down and it's certainly not a clumpen mess!

Sure, down will get wet if you lay in a puddle of water but then so will a synthetic. You'll have a miserable experience in both.

Even a modicum of care is enough to ensure that a couple of nights, at least, in humid/damp conditions won't affect the performance of down. Don't treat it like a prop forward's jockstrap!

If you wash your down at home hydrophobic dries faster/lofts easier with less agitation, there was a huge difference between washing my coated and non-coated sleeping bags.

Dirt/skin greases tend not to stick to hydrophobic down as much so potentially can smell less (so requiring less washing).

Also hydrophobic down does cause manufacture pollution which is why Patagonia don't use it.

In humid conditions, especially in winter, when after a few nights the bag has accumulated some ice inside the filling from condensated body moisture, regular down would loose a significant amount of loft. Since I use a bag filled with hydrophobic down (from Cumulus), I find that the loss of loft is reduced.
Once back at home, I weighed the bag to find it had put on 250 g of weight, all in form of ice on the inside of the outside fabric. With a less breathable fabric than down proof 7D ripstop nylon (about any other down proof fabric is less breathable than this), the ice accumulation would surely be even more.

Similar issue with a quilt I made for my girlfriend (hydrophobic down I got from Cumulus). Her quilt simply never looses loft.

I don't see the sense in waterproof outer fabrics. They hinder moisture transport from our body to the outside. In winter (freezing temperatures) I often bivy out with no other protection but just the lightest fabrics enclosing down. The bag can be full of snow, but with its insulation properties, the bag is too cold on the outside for the snow to melt. No bivy bag or hard shell fabric needed.
I've come home after winter mountaineering in poor show weather and had snow fall out of the inside of the bag when hanging it up to dry, so have put my bags through some testing situations.

Damp spots from touching a single wall tent have never become a problem, even thin fabrics can handle such situations.

So basically I only find bivying in rain to require protection for a down bag/quilt.

Long story short. If I have the choice of 850 cuin down or 850 cuin hydrophobic down, I choose hydrophobic. If I have the choice for a hard shell outer fabric or lightweight fabric, I choose the latter.

No matter what Peter Hutchinson says. I made my own picture and experience and that counts for me.

This is arguably the most important consideration:

https://responsibledown.org/

Richpips wrote: ↑Sat Jun 20, 2020 6:02 pm PHD reckon that hydrophobic down performs less well than untreated down.

https://www.phdesigns.co.uk/down-gear-in-use

Having once-upon-a-time got a synthetic bag wet I can tell you that keeping water away from any sleeping bag whatever the filling is important.

Good link.
Sounds like the only value in treated down, is that it dries quicker. I took it that the treatment would prevent it from soaking up moisture.
I've only had synthetic bags before, but the lack of compressibility is making me consider a three season down for bike trips.

Dean wrote: ↑Sat Jun 20, 2020 7:34 pm Also hydrophobic down does cause manufacture pollution which is why Patagonia don't use it.

There are different ways how hydrophobicity is brought into down.

First, down contains natural fats and is protected a little bit by its nature.
Some manufacturers believe hydrophobic treatment destroys this natural protection.

Secondly, there are different ways to treat down for more protection. Some are done similar to proofing a fabric (chemical treatments). Nikwax has been producing hydrophobic down without the highly problematic PFCs. Not every chemical treatment is problematic.

Other treatments are done by functionalising the down surface in a gas plasma (physical treatment).
Gas plasma requires a vacuum, a bit of electricity and a gas. Some treatments can be done with nitrogen, argon, helium even oxygen and other gases. I don't know what gases can be used for plasma treatment of down, yet I know enough about chemistry and biology, to know that above mentioned gases aren't problematic.

Lets remember Patagonia still waterproofs their garments with PFCs, stating alternatives aren't as effective, yet Nikwax has proven PFC-free garments to be just as functional. For many a few years now.

A bit hypocritical and misleading from Patagonia to say hydrophobic down (treatment) is too harmful to the environment.