Understanding rain gear materials?

" eVent type. Fabric breathes better. Pricey but a moderate weight. Is always waterproof. The inner layer may get clogged with oils, dirt, etc at which point it will not breath much. "

e-vent : cheap for what it does, which is breath very very well. but, if the dwr goes away (and it will), it wets out, and you will be drenched in a few fast miles in moderate rain.

i swear to god that mine leaks, but every time i test it in the shower, it's 100% good.
this leads me to dwr failure, which i have not yet attended too (my bad) as the demon.
but as far as breathing nicely under a vast array of conditions, e-vent's the bomb.

v.

You need to split WPB into categories, PU and ePTFE. PU requires a phase change for humidity to pass through — from vapor to liquid absorbed through the PU laminate, to vapor on the other side. ePTFE has pores that vapor can pass through but liquid cannot.

Gore-Tex is ePTFE, with (until the 2013 Pro fabric) a PU layer. Gore had an issue many years ago where body oils would degrade the ePTFE layer to the point where it was no longer effective and "solved" the issue with a light PU layer to protect the ePTFE, effectively making it far less breathable.

The new Gore-Tex Pro material for this year is 3-layers of ePTFE sandwiched between a nylon outer and a wicking tricot inner. Presumably that means they came up with a solution for the ePTFE longevity issue.

eVent is purely ePTFE. Comes in two variants, a more durable 3-layer ePTFE sandwich, and a less durable "2.5-layer" ePTFE covered in nylon on the outer side. eVent claims to have solved the ePTFE longevity issue, and since they are simply ePTFE with no protective coating, they can actually vent humidity directly without a phase change.

Pretty much all other "proprietary" laminates/coatings are PU-based, such as Precip, Membrain, H2No, Conduit. Depending on the technical expertise and skill of the fabric mill(s) sourced, they can range from very thin and fairly "breathable" to thick and fairly durable.

As far as longevity goes, I've caused a Gore-Tex Pro Shell (different from Gore-Tex Pro Fall 2013) to start to delaminate in as little as a year and a half. Some initial research seems to indicate that some people's body chemistry is more effective at breaking down WPB than others.

My 2.5 eVent has started delaminating after several years. On top of shoulders and at back of neck.

I suspend pockets from the shoulder seam, so there's a layer of nylon inside on the front side of shoulders, and that is not delaminating.

So, that's consistent with the theory that 3 layer is more durable than 2.5.

But it weighs more, so that's the trade-off – more durable and heavier, or less durable and lighter.

Stephen,

That was the best short explaination of WPB laminates and their mechanisms of vapor transport I've seen to date. I hope everyone here at BPL reads it.

I have old GTX parkas (thankfully both have pit zips), a Cabelas Rainy River PacLite GTX rain suit and an REI Kimtah eVent rain suit. PacLite is barely "OK" with very moderate exercise and eVent is amazing for its breathability in normal backpacking.

"The inner layer may get clogged with oils, dirt, etc at which point it will not breath much."

This applies to any air permiable membrains. This simply means you need to clean your jacket. Event is treated so that oil will not stick to the ePTFE membrain. Washing removes the oils restoring breaathability. As stated earlier the original Gortex had problems with oils but becasue the oil sticked to the ePTFE and washing would not remove it. Gortex solved that problem by adding a very thin polyurethane layer to the ePTFE to solve the problem.

"Propore type. Material breathes the best."

Based on the numbers I have seen it isn't event close to Event. It is however air permiable so the humidity inside the jacket stays low while regular polyurethane jackets get very humid inside before they start to breath.

In terms of breathability Polartec NeoShell is reported to have much higher breathability than Event. It uses spun bonded polyurethane fibers to creat the membrain. This also makes it air permiable and the fabric can streatch somewhat. ePTFE and regular polyurethane jackets cannot streatch.

You can't say that ANY of those "is always waterproof" except the nonbreathing plastic/vinyl ones- the equivalent of a rubber rain slicker. ALL of the others can wet out once the DWR is defeated, either by wear or just extreme conditions- even PTFE or eVent. And you can still sweat yourself into clamminess in any of them, especially the non-breathing stuff.

This is important to understand:

*** There is no truly good raingear option.***

At this point in time you need to be very Buddhist about the issue and just accept this. You'll be happier.

They all fail somehow under certain conditions. IMO eVent (and it's Gore near-ripoff) is probably the best, because it breathes very well and has decent waterproofness if treated well. However, I have never used Paramo and thus I can't comment intelligently on it, but I understand that it is heavy and hot and best used specifically in cold/wet conditions.

If you ever design a WPB material that is actually WPB please let me know, because I want to buy stock in your company.

nm

(I got schooled by the link below.)

There is probably a range of conditions where you'll be a little drier with eVent than Gore-Tex. And you'll be a lot drier with eVent or Gore-Tex than clothes that are completely waterproof or not waterproof at all.

If it's real cold or you're exercising less vigorously then you will sweat less and be fairly dry with eVent or Gore-Tex. And if it's light rain or brief heavy rain then it won't wet out and stay wetted out.

If a lot of your time is spent in these conditions then eVent or Gore-Tex are really great.

If conditions are worse, then you'll get wet, so you need another strategy. Wear as little as possible (that gets wet) and have dry gear inside pack. Set up shelter, get inside, take off wet clothes and put on dry clothes. Usually, I can set up shelter, get inside, and my wet clothes will dry pretty good just wearing them.

One word: ventilation. Lean to designs with all the vents you can get: pit zips, venting pockets, etc. Look for front zippers with with storm flaps that have snaps or Velcro tabs, so you can leave the zipper open and vent via the gaps in the fastenings.

For a jacket, I'm using an Outdoor Research design with the "Torsoflo" side vents, which are basically pit zips that go all the way to the hem. You can open them up and flap the front of your jacket over your hip belt. That allows air circulation up the front and sides that are normally pinched off by your pack suspension.

Ponchos have great ventilation and completely cover your pack, so you don't have a soggy suspension when the rain quits. They are weaker for bushwhacking and exposed windy conditions. To tame a poncho in the wind, I add a "monk's belt" with some light line and a toggle, wrapping it under my pack and lodging on top of my waist belt in front so it doesn't slip down. They aren't a slick smooth tailored fashion statement, but nothing will give as much coverage for the coast weight: head to knees plus pack for $60 and 7oz and you get a good emergency shelter in the bargain.

I've seen for a while on the subject

http://blistergearreview.com/features/outerwear-101

Thanks for the link. Great article.

And it explains how fouling can, in fact, lead to water passing through an ePTFE membrane.

Nm

And yet More excellent information.

It’s the grad level follow-on to the link above.

"However, I have never used Paramo and thus I can't comment intelligently on it, but I understand that it is heavy and hot and best used specifically in cold/wet conditions."

The first part depends. If you buy a full Paramo jacket, it's going to be somewhat heavy to downright heavy though Paramo is slowly but surely changing that. However, i have a Nikwax Analogy pump liner from Cioch, that weighs 8.4 oz. I already have a Houdini Wind shirt that weighs a little over 4 oz. Combine the two, and we're only talking about 12 and a half ounces for a flexible, adaptable system that will work well in most conditions (except warm weather, or in particularly hard driving rain).

I also have a Stoic Vaporshell jacket, which is actually heavier than the combination of the above. Sure, it will be cooler though and more suited to those 50 to 70 degree range.

That's one of the problems with the Paramo type system is that it runs warm, since the Pump liner is basically a lighweight, thinnish sort of fleece (well, pile on one side, smooth on the other) and you're combing it with a windshirt outer layer, so two layers will be warmer than an equal thickness of one layer (traps more air potentially). However, i think some people are a little too obsessed with staying dry. Who really needs to stay perfectly dry when it's 70 to 90 degrees out? My philosophy, is get almost nekked and let self get wet but stay very active while same (and eating thermogenic foods). Or, use thin polypro shirt and very thin, lightweight nylon shorts (like some of the running shorts) or thin polypro baselyaer pants. If temps start to dip, these fabrics will dry quite quick from body heat. (then layer and protect accordingly).

Also, i'm working on ways to minimize the warmth of the paramo type system. One way is wearing a fishnet baselayer, which when you get the chance, you can dump more hot humid air quickly, cooling you down quickly. (pit zips would be awesome for this, but i'm a little hesitant to cut into my Houdini).

But essentially you and others are right, there is no perfect system. I'm near convinced that UHMWPE fibers holds a key to a revolutionary WPB system, but there are kinks to work out with this material. One is that it is so slippery, that it's difficult to weave or knit it like other fibers and have it stay together without coatings (which add weight and reduce breath-ability and potentially change the hydrophobic levels). Something that i would like answered, is how much strength does this material loose when it's melted slightly (i know it loses some)? If it's still strong after, but not crazy strong like it is under ideal conditions (e.g. dyneema cord that hasn't been heated at all) , it just might work well with either spun bonding it like with certain tyveks, or layering like two super thin, but tight weaved fabrics and bonding them via a calendaring type process (rollers that exert a lot of pressure and are heated).

Also, another variable i don't know much about is how the material handles oils. If it's at all oil attracting, it will developed issues like some of the more traditional WPB technology does. Since it's so hydrophobic in nature, it will be hard to wash well. It may be that UHMWPE fibers may only be a good outer shell solution, while still using a more traditional membrane (whether Goretex, eVent, Neoshell) or Paramo type system. Super light weight, no DWR coating needed (because SO slippery and hydrophobic), and near bombproof. Just have to deal with the breathability of the membranes used, or in the case of Paramo still having issues with hard driving rain.

Another benefit of UHMWPE fibers and material is how thermally conductive the material is. Heat passes through this material very easily and quickly. Amazingly so.

However, apparently i'm the only one who takes it seriously at all.

Killer article.

Let's support the OP by asking what's really important (according to the article/common sense): What's the best DWR right now?

I have a rain jacket but don't use it much. Personally I have just been using a wind jacket with a Patagonia R2 fleece under it and a poncho/tarp over that with a trash bag rain skirt if I need to for the rain and/or cold.

@Dale W

Is this the OR Rampart jacket you are talking about? Because I am thinking of getting one.

Outdoor Research has a number of rain jackets with the Torsoflo pit-zip feature. My jacket is the Spring '12 version of the Panorama jacket using Pertex Shield rather than the OR Ventia membrane in the current model. I picked it up at the OR parking lot sale this last Spring.

This summer was so dry that I really didn't get a chance to give it a good soggy multi-day test. I have worn it through a couple short drizzle-fests and it seemed like a pretty typical 2.5 layer rain shell to me.

Regardless of the shell and membrane used, the ability to open up the whole bottom of the jacket is great. It has 2-way zippers, so you can vent it like a more conventional pit zip while still having it open at the bottom, or just do the pit zip thing. The whole front of the jacket can flap over your hip belt like an apron and the hand pockets are unhindered as well. It allows airflow all the way up to your sternum strap. It could use some snap tabs at the bottom I think. The front zipper does not have Velcro or snaps on the storm flap, but that is less of a concern with the big side zips. The pockets have mesh linings, so they can vent too.

I think I would end up battening down all the hatches in a real downpour, but hours of drizzle is more the PNW standard. With 45F-50F temps, high humidity and lots of switchbacks, ventilation is paramount.