Originally Posted by Erick L
Fleeces are made from soda bottles but nobody says they are the same thing. Gore doesn't claim waterproofness from their windstopper fabric. It doesn't stop water (the fabric, not just because of untaped seams), yet it breathes poorly.
*WARNING, 3AM CENTURY ON 2 HOURS SLEEP RANT*
Your analogy is just about as wrong as me saying, there's iron in my blood, my bike is made of iron, therefore I am a bike.
A better analogy would be to compare a road spec porsche and a GT porsche. Both porsche 911's, same motor, same essential layout, tuned and toleranced differently in manufacturing.
Gore used to make windstopper shells (not windproof fleece as you know it now) alongside goretex shells.
Windstopper is the born again fabric that used to be known as "Activent." It doesn't claim to be Goretex because of marketting and manufacturing, not chemistry.
The reason why they rebranded it windstopper instead of Activent was that Activent, as you've said, breathed too poorly (being that it essentially was ePTFE, or goretex) and cost ended up almost the same as goretex (essentially a nonwaterpoof spec'ed goretex jacket at the same price). It was discovered by the mountaineering community that the only specification difference was that Activent did not require taped seams, waterproof battens for the hoods and cuffs, storm shields around the zippers, and protection for the ePTFE layer as mandatory. Plus mechanically, the windstopper membrane is, as I've said before, a THIN version of goretex. It can't pass the pressure test that gore does for its actual goretex fabric.
There's a good reason why gore doesn't claim waterproofness in their windstopper fabrics and that's because they're a supplier to manufacturers who don't have to build to the "waterproof" spec, the Gore mannequin tester could tell you more about that. I think the confusion here is that you're talking about a goretex jacket (which has to be built up of a whole host of features before Gore can *certify* the jacket with their shiny "guaranteed" emblem) and I'm talking the goretex material itself which only has a market name of Goretex (which is just the white teflon-like layer you see in 2-layer goretex jackets) but actually shares its properties with a wider range of products from Gore, including DryLOFT (which btw is also a windstopper version of "Goretex"). Actually the product literature for DryLOFT hints at this. If you can find it from Gore, I remember from discussions in the tent at 15000ft when I used to some light mountaineering, that right on the product literature of one of our tent mate's new sleeping bag was written something along the lines of, "DryLOFT is windproof, highly breathable, and provides protection against condensation and snow but due to design is not waterproof as the seams are not sealed." If they were sealed, then essentially you have a goretex bag that will pass the nonpressurized waterproof test.
If you know anything about computers, think, is a celeron a pentium? No a celeron is not a pentium, it says so right there, CEL-ER-RON. And the other one says PENT-I-UM. As far as I can tell, the celeron *IS*, that's right IS a PENTIUM with a lower L2 and FSB.