- Mar 29, 2017 at 1:48 pm #3460321
so if the system is DWR dependent … we know everyone and their BPL dawg here wears windshirts for everything all the time … and most of us have C6 florucarbon DWR …
we know that DWR wears out every quickly on the shoulders under pack straps, the back against and hip against the pack and belt, and in the outside sleeves …. pants DWR get worn out even faster of course
unless you always have fairly fresh DWR … or EPIC … then i suspect after a bit youll have a HH under 300 in quite a few parts …
if you want to check just run yr windshirt under the tap for the aforementioned parts and see if the water just beads right off
you can read about various brits who have had issues with paramo … possibly because they didnt reDWR them enough ….
fluffy like a bunny and fuzzy like a bear …
;)Mar 29, 2017 at 2:17 pm #3460328
Regarding pushing vs pulling, hydrophobic vs hydrophilic, I would prefer that you are correct and that they are equivalent in this application. The advantages of not being DWR-dependent are many. But what about Paramo’s rain room claims? They claim that their system can keep an inactive wearer dry for 4 hours under heavy rain, while PCU/Buffalo only seem to advertise warmth while wet for an active user.
I’m really only interested for active applications, personally, since I will take my DriDucks for insurance and static situations anyhow, so what’s at issue is for how long, and under how heavy a rain, one can remain active and comfortable. You, and the military, seem satisfied with the non-DWR variant, so I’m sure it works; I think I’m just compelled to try to optimize.Mar 29, 2017 at 2:41 pm #3460334
Richard- thanks for the explanation (and diagrams)!Mar 29, 2017 at 3:38 pm #3460345
The presence or absence of DWR has no effect on the >300mm HH of a woven fabric. It remains largely unchanged for the life of a garment.
Non EPIC woven fabrics don’t stop breathing when the DWR is degraded but, like WPB fabrics, they do reduce the breathability rate in the degraded areas.
The worst case performance a 5 CFM microfiber shell degraded from sustained rain versus a typical UL WPB shell ( MP PU A = 24% orig. vs microfiber fabric =26% orig) still results in ~32x higher moisture transport through the microfiber shell when active at a backpacking rate of 7 MET.Mar 29, 2017 at 4:35 pm #3460357
As you increase the moisture transport layer thickness, it will increase the amount of time it will keep you dry. Correspondingly, it will reduce the thermo neutral temperature… so, companies typically advertise only selective test results that the marketing department deems beneficial (smile).Mar 29, 2017 at 5:52 pm #3460381
Paul S.BPL Member
If you’re hiking in conditions too warm for a Cap 4 with dry conditions so you have just a thin base layer on and then rain hits, what do you do? Throw your Cap 4 under your wind jacket and march on, or should you remove your thin base layer first?Mar 29, 2017 at 6:10 pm #3460387
the DWR has no effect on how much water passes through the nylon from the outside?
in other words its only for breathability?
i dont know about everyone else … but ive found a soaked through windshirt (or nylon pants) clings to your skin or layers more than a klingon
if its that warm just keep walking … when you stop just wring our that thin base layer which shouldnt hold that much mositure
;)Mar 29, 2017 at 6:25 pm #3460399
Re: layer thickness – a parsimonious and compelling argument:) Thanks
And thanks for your calculation of breathability of wetted out fabric. One question on that: Dave Chenault tested an Alpine Start when new using the cup test, where it performed excellently. Several years later, the same jacket leaked like a sieve. Dave attributed the degraded water-resistance to DWR depletion. How do I make sense of this in the context of your statement that “The presence or absence of DWR has no effect on the >300mm HH of a woven fabric. It remains largely unchanged for the life of a garment.”Mar 29, 2017 at 6:35 pm #3460403
If you’re hiking in conditions too warm for a Cap 4 with dry conditions so you have just a thin base layer on
I would ask WHY do you have a base layer on?
With normal levels of exertion a simple windshirt should be enough for most physiologies down to a few degrees above freezing and up to a gentle wind. They are called windshirts after all.
There is this strange obsession with wearing too much clothing and then complaining about the sweating this causes.
CheersMar 29, 2017 at 6:45 pm #3460405
Woubeir (from Europe)BPL Member
so are you suggesting wearing a windshirt on bare skin ?Mar 29, 2017 at 6:48 pm #3460408
Paul S.BPL Member
A base layer helps against sun and from abrasion (pack or environmental). My scenario is essentially how effective is the system with a base layer underneath.Mar 29, 2017 at 7:06 pm #3460413
Paul- in your scenario (remembering our metabolisms are all different) I would keep walking until it’s no longer comfortable (ie too cold), then throw the Cap 4 over the base layer
my experience is that a good base layer + good windshirt is effective when moving in rain; colder rain add the Cap 4 to the mix; crazy cold rain add the hardshellMar 29, 2017 at 7:24 pm #3460420
so are you suggesting wearing a windshirt on bare skin ?
Col d’Anterne in France.
I am wearing one of my MYOG Taslan windshirts in this photo, with NOTHING underneath. My wife was dressed the same. Yes, windshirt on bare skin.
We have been dressing like just this for the last 10 years or more. (At leats, since my MYOG article was published in 2007.)
We add a light base layer when the temperature goes below 0 C.
CheersMar 29, 2017 at 7:30 pm #3460424
Some windshirt feel pretty klingon against the skin when wet ….
Its an easy test …. Just soak your windshirt in the sink, put it in bare chested and walk around outside tonight …. If its cold and raining even better
;)Mar 29, 2017 at 7:47 pm #3460430
Brad RogersBPL Member
@mocs123Locale: Southeast Tennessee
The Taslan that Roger is using for his windshirt looks more like the fabric that we might see on a button up “trekking shirt” so it would feel much better against the skin than what most of us think of as a “windshirt”.Mar 29, 2017 at 7:48 pm #3460431
Thank you for the link to the UK climbing forum’s discussion of Paramo. My biggest take-away was, “many of the forum posters didn’t seem to understand how Paramo works”. It was a mixture of “its works for me versus “it doesn’t work for me” forum posts. What was largely missing was the “why”.
The primary recurring issues that stood out to me:
Mar 29, 2017 at 8:01 pm #3460432
- They were sometimes mixing wax and fluorocarbon DWRs with predictably poor results
- They were sometimes assessing its efficacy for static or low-active (MET) activities rather than being aware that it is not designed for that
- They were sometimes not aware of the HH provided in this type of system versus what is required to kneel or sit in water
You said, ““The presence or absence of DWR has no effect on the >300mm HH of a woven fabric. It remains largely unchanged for the life of a garment.”
The Black Diamond Alpine Start is a knit fabric. Its HH will decrease in proportion to the degree it is stretched. My GUESS is that there may also be a progressive increase in the pore sizes from the elastane stretching from high dryer heat. The care tag on this garment specifies “low heat” for either tumbling in a dryer or ironing.
In 2005, Natick Labs published a 66 page research report on DWRs. It concluded, “None of the water-repellent treatments significantly affected the breathability, airflow resistance, or pore size of the BDU fabric.” Their research conclusion matches my own tests on windshirts.”Mar 30, 2017 at 12:27 am #3460475
paramo should in theory be basically rain proof for a few hours …. thats what they claim to test at leeds U’s rain room
so basically you are saying that theres no HH difference between a fresh new windshirt with brand new DWR and an old used one with the DWR worn off ?
;)Mar 30, 2017 at 1:15 am #3460478
Armand CBPL Member
Not a fan of wind shirts generally and have moved away from them.
Even my beloved Houdini is now shunned.
All have been replaced with light soft shells like the BD Alpine Start and OR Ferrosi.Mar 30, 2017 at 7:03 am #3460500
funny I consider my Alpine Start a windshirtMar 30, 2017 at 7:56 am #3460507
Woubeir (from Europe)BPL Member
windshirt … softshells … in which way do their functions differ ?Mar 30, 2017 at 3:28 pm #3460610
Brad makes a good point. My Taslan ‘windshirts’ may well feel different from some current windshirts made from a very smooth glossy light fabric.
However, the feel of the fabric does not change the fact that for at least many people, if not most, the normal amount of heat generated when you are backpacking is high. With this amount of heat you simply do not need any more clothing than a simple shirt.
CheersMar 30, 2017 at 11:21 pm #3460695
Steven ParisBPL Member
@saparisorLocale: Pacific Northwest
i walked the dog yesterday in typical Portland spring weather: steady but lightish rain, mid-40s. I decided to wear an OR short-sleeved echo shirt, a Cap4 Thermal Hoody and a Squamish windshirt. It was actually a little warm for the conditions but ok. The Cap4 was only a little damp in the sleeves and chest after an hour and would have been fine in camp.
My problem was that the Squamish’s hood got wet enough that it felt like it was letting water through the fabric. I didn’t have the Cap4 hood on underneath so it was wind shirt directly against my head. I don’t mind the thin unstructured hood in the wind but it definitely was a weak point without some layer underneath. I feel there’s a question somewhere in here but it’s late and i can’t quite formulate it. Any thoughts about the hood area in these systems?Mar 31, 2017 at 1:34 am #3460711
A Cap 4 hood addresses your problem in two ways:
1) it will pull the liquid water away from your head
2) it provides “give” under your windshirt, when it is impacted by a rain drop, to reduce water penetration ( Impulse-Momentum form of Newton’s 2nd Law)Mar 31, 2017 at 2:26 am #3460712
Me, I just wear my large-brimmed Australian cabbage hat under my hood. The brim at the back keeps the hood off my neck, which is … nice.
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