Quilt with a PU coated shell

Have you heard any advice on this?

I’m ready to drop serious coin on a PHD M.Degree 200K. I have two choices of fabric for this; their 7X 7D fabric, the lightest they offer. I suspect this is similar to RBTR’s Membrane 0.56 fabric.

The other option is their “hypershell” which sounds like a 7D with PU coating, they say 1000mm HH which is pretty good. Sounds like like the other similar fabrics out there. It only adds 15g to the total weight for potentially a lot of water resistance benefit… though to be honest I don’t expect to have many issues with how I camp, and I can always put that weight into better rain protection (eg bivy or tent or tarp weight).

I’m mostly worried that the breathability of the PU coating will be pretty low. The down isn’t treated down, its rediculous 1000 loft stuff. So I’m worried sweat vapour won’t escape well enough particular on longer trips, affecting the down lofting. And of course it won’t dry out anywhere near as fast if it does get a bit wet.

The other thing is I suspect that because of the PU coating despite being heavier it won’t be as durable as the 7X option. Given the amount of coin I’m dropping (even though it really isn’t an issue, this is a present to myself for finishing my masters) it more just sucks if the thing gets a tear somewhere.

I’m guessing if the 7X is similar to RBTR’s membrane 0.56 then it will have a decent DWR so the gap between that and 1000mm HH for the kind of random drips and light spray it might experience isn’t really that big of a deal.

Anyone have any thoughts on the matter?

Hmm. My older Feathered Friends Lark has a PU shell and I’ve had no issues with it…At least 80 nights in that bag.

I’ve not had any issues with the shell on my own quilt, the shell is the UL Robic fabric with similar specifications, ditto the shell on my DAS parka

My experience is that the type of Polyurethane coating that deteriorates most easily is the kind made with a water soluble base. For a time it was advertised as being more eco friendly, in reality it didn’t last as long as the solvent based coatings. I don’t know of anyone still using the water based formula in quality gear. It was a cheap alternative.

Sort of like the cheap pale canned salmon that advertised “doesn’t turn pink in the can”.

Storing PU wet is not good for it. Tumbling your bag on warm in the dryer for a few minutes before you store it might be a good idea.

I had an early Goretex down bag, the Gold Kazoo, that lasted we figured about 1300 nights over 7 years  before it delaminated. Boy were warranties good back then. They replaced it with another down bag (not Goretex, they stopped using it). The down in the Kazoo was still good, and I otherwise would have still continued to use the bag if not for the warranty.

You can always find a use or another user for an old down bag.

Thanks for the responses! I reckon I’ve seen cheap PU jackets and stuff sacks with the water solubility problem…the PU side gets sticky and sticks to other fabcric faces?

I went and thoroughly checked out a Sea to Summit Spark sp2 (the latest updated version) yesterday….I was significantly impressed with the build quality. I can get it for $400 dollarydoos (that’s Australian money)…about $600 less than what a PHD M.200K would cost. 100grams more. The Spark was so comfortable…and I REALLY liked some of the design features… the way they did the hood cord, the hood shape, the zipper tape….it all just works for me. And it felt warm…I have a feeling I’ll be good to the “lower limit” no worries.

Getting in the spark made me feel kinda stupid for considering spending $600 to save 100grams, that may not even be a weight saving once the DWR lower loft down (hence better WR and damp warmth) is taken into account and the draft collar (better warmth retention again-though I can add this and weight to the PHD doing the build your own option). The hood is also slightly more shapen going by the images. Actually I think the hood fits me better than my last down bag, a 2010 model Mountain Hardwear Phantom, which I thought was a really well designed hood.

One thing is shit though; the stuff sacks that come with the Sparks. WAAAAY too small. Took me a solid 5 mins to stuff it in. Even their “storage” thing is tiny…. honestly with that much down I’d normally get a stuff sack that big for my pack! (and compress/allow to loft internally). Sleeping bag was designed by someone who REALLY knew what they were doing. Stuff sacks by marketing department.

(thread drift, sorry)