I’m making a quilt/bivy
I want the outside to be waterproof enough to ward off dew and mist.
I don’t care about rain. I use my tent in that case. Rain is more difficult because it hits the fabric and creates a lot of pressure. You need higher HH, like waterproof breathable (heavy) fabric.
I looked at membrane 10 0.66 oz/yd2 RSBTR and Momentum 50 0.7 oz/yd2 thru-hiker.com
Test setup – ring (masking tape), fabric over that, put in 1/2 inch of water, paper towel underneath. 1/2 inch of water is more than anything that will collect on it in real use
The membrane leaked all the water through after about 10 minutes. It’s funny, it just sits there for a long time, then all of a sudden finds a path through, then it all leaks through pretty quickly
The momentum I bought about 2018 leaked through after a couple hours.
I also tested momentum I just bought. It didn’t leak after a couple hours but I aborted the test because there was water from the 2018 momentum getting all over the place. The just purchased momentum might be better, but it could just be random variation.
The momentum is significantly better – the DWR is better. According to my crude measurement. $13 a yard
The membrane is probably just fine. Could be that it’s just my crude test. $10.50 a yard.
I did the same test several years ago comparing to some other DWR nylon. Same result. Actually, that fabric was worse.
