Outer layer UQ fabric choices

[Dano1972]

I'm about to place a large order at Rip Stop by the Roll. 2 of the under-quilts I'm planning are sub-20 degree. I'm trying to determine which fabric to use for my outer layer to provide the highest wind resistance. Membrane 7 is listed as "Highly wind resistant -CFM of 6.3", yet none of the other fabrics contain permeability stats. While I like the idea of creating an ultra-light quilt entirely out of Membrane 7, I'm concerned about air-permeability for use in lower temp quilts, as my current <20 degree is made entirely out of Membrane 10 and I noticed decreased performance during a windy early spring hang. Does anyone know how M7 compares to calendared 1.0 oz HyperD vs M10 vs M15? Any suggestions on which material would give me the highest performance without the need for a UQ protector? Thanks in advance!

[jmnicolas]

Funny you are asking. I had the very same question recently and I did struggle a lot to find CFM values. Fabric makers and gear manufacturers (at least those I did contact) are reluctant to disseminate specs (beyond weight and HH). I found Argon 67-90 is around 40-49 CFM (partially air permeable; one hard-to-verify source grabbed on the web). Quantum Pertrex is around 3 CFM (fairly air resistant). I managed to get my new UQ made out of Toray Airtastic which is <1 CFM (windproof)! I did it for the very same reason you mentioned, ie to mitigate the windchill issue when paired with my minimal tarp. I will post the whole story with some more tech details and more specs later this week. So, stay tuned!

I doubt you can find Airtastic as bulk material. Pertrex Quantum might be easier to get. Dunno.

[OneClick]

I would be more worried about keeping moisture in than I would with wind getting thru. The latter is easy to prevent. Trapping moisture inside a less-breathable quilt could be a disaster. In the winter it's normal for me to have a lot of frost building up on the outside of my quilt in some spots, which can look unnerving, but I'd rather have that opposed to moisture on the inside because it couldn't breathe well.