DIY DWR for down ??

I used nikwax down wash direct on my down vest which has both treated and untreated down.  It seemed to work okay.

Although my bias is to not use DWR down.

I have a sleeping bag with pre-treated DWR down and I don’t really think it’s a huge advantage. I have a big white cockatoo, too. Birds get wet. Body heat and air dries their feathers and they get fluffy again. Getting feathers wet is not dangerous for the lifespan of feathers.

From Western Mountaineering’s FAQ:

Why doesn’t Western Mountaineering use hydrophobic down in any products?

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 repellent 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.

Once before I used Grangers wash+repel down 2 in 1 which is supposed to add DWR to untreated down

It seemed to work okay

I think in the future I’ll just use the nikwax which doesn’t add any DWR to the down

I think I’ll use the Grangers for washing a DWR rainjacket that has no down in it

I think I was given the Grangers and bought the Nikwax because I didn’t want to risk damaging my down.  No reason to wash it with a DWR treatment.

Naysayers of down treated with DWR just don’t get it – or refuse to believe it works.

Nope, we’re just waiting for evidence.  Water resistive treatments on everything else have to be reapplied after a year or two at best, so why should I believe they will last forever on down?  It’s an extraordinary claim that requires solid evidence, especially given how seldom untreated down has caused anyone any problems.

Maybe naysayers refuse to believe it works because it doesn’t work?

In my opinion, DWR or regular down work about equally good.  I have a vest with both in it (because I ran out of the DWR down so I used some regular).  I can’t tell a difference between the two.