PacLite vs AscentShell

[Gerry V]

Hi,

I have been looking at inexpensive hard shell jackets.  I have lighter options for the nicer 3 seasons but need to replace an old 3L goretex shell for winter and the edges of the shoulder seasons.  Mechanical venting is a must as is durable waterproofing, good detailing a big plus.  So far my top choices are the Marmot Minimalist in Goretex PacLite and the OR Guardian in AscentShell.  They can be both be had for just over $100 generally.  They are both just under a pound with the Guardian being almost 2 ounces lighter.  I know that is heavy but have not really found anything durably waterproof and that inexpensive.  I would prefer a really nice 3L goretex hard shell but this is the budget and realistically I will probably use it more for day hikes and skiing, though it needs to be up for backpacking as well.

I really like that the Guardian is air permeable, lighter, and has the OR guarantee.  I am worried it might not be as up for keeping me warm and dry in the worst case cold all day rain on multi day trips.

The minimalist is appealing because it seems like the heavyish Goretex fabric might keep me warmer and dryer.  I have heard the Marmot guarantee is not nearly as good, though I have had success over the years with their products.

I have no experience with either fabric or jacket and would love to hear others opinions.  Likewise if I have missed other options that are lighter or better performing but still inexpensive I am open to it.  Thank you so much!

[Stephen Seeber]

AscentShell is the same basic technology as Polartec Neoshell and North Face Futurelight.  It performs similarly to both of those products. A major trade off between the jackets will be Hydrostatic head (water resistance) vs breathability.  By my test, the breathability of the AscentShell will be nearly double that of PacLite.  And, that is big.  The drawback could be water resistance.  The PacLite should be in excess of 30000mm.  The AscentShell will be around 16170mm.  In terms of use, if you are hiking in 40 mph or more winds during a heavy rain, you will probably get wet in AscentShell.  If you go sliding in the snow (seems unlikely for a jacket), you may get wet in the AscentShell.  But, for general use, the water resistance of the AscentShell should be adequate.  I made my measurements on an OR Skyward II jacket.  The  Guardian should perform similarly.   The Guardian seems to have a more complete feature set.

[Richard Mock]

Great reply

[Gerry V]

Thanks for the information.  The breathability is tempting.  How are you liking your Skyward II?

What about when the DWR is gone and they wet out?   My understanding of the Paclite is that it will lose all breathability but still be waterproof.  Will the Ascentshell get saturated and possibly start leaking when it wets out in heavy rain?

Thanks again!

[Stephen Seeber]

I just got it for testing the fabric.  If I were to buy one it would be the Guardian.  When the DWR wets out, the face fabric will gain some weight and breathability might be impacted, depending on conditions.  Both of the jackets you are considering should have a similar issue.    Just get in the habit of washing your garment periodically and applying DWR.  I wash my outerwear garments fairly regularly and apply DWR periodically.  If you get the Guardian, post your thoughts.

[Richard Nisley]

Gerry,
You said, “What about when the DWR is gone and they wet out?   My understanding of the Paclite is that it will lose all breathability but still be waterproof.”

Paclite will experience a ~ 25% breathability (MVTR) reduction after the DWR stops working. In contrast, AscentShell, will experience a ~ 100% reduction after the DWR stops working.

[Stephen Seeber]

Proper garment maintenance should avoid failure of DWR.  If DWR failure occurs, and the face fabric wets out, the garments you are considering will remain waterproof in normal circumstances.  However, breathability  and therefore vapor transfer from the garment interior to the outside will be impacted.  The impact will be determined by the vapor pressure differential across the garment.  This in turn is a function of temperature and humidity on each side of the jacket.  Suppose the temperature inside the garment is 90oF with 90% humidity.  The vapor pressure is .63 psi.  Suppose the temperature outside the garment is 50oF with 50% humidity.  The vapor pressure on the outside is .1 psi and the pressure differential across the garment is .53 psi.  Plenty of force to drive vapor through.  Now, let’s wet the fabric so the temperature is 50oF with 100% humidity.  Now the force across the jacket is reduced to .45 psi.  The pressure differential is reduced and vapor transfer will be reduced.  Depending on the configuration of your layers, the amount of vapor you are producing and the outside temperature/ humidity conditions, you can come up with a situation where vapor transfer is reduced substantially or even completely.

[Richard Nisley]

In the first paragraph, If the word “avoid” is replaced with “reduce” or “minimize” this statement has more credibility relative to C6 used as a DWR.

In the second paragraph, this is a valid description for the bicomponent diffusion physics WPB membrane of Paclite; not AscentShell, which relies on a microporous physics WPB membrane.

Example explanation of how microporous membranes, like AscentShell, work in the rain:

The increased heat loss under conditions of rain resulted in the formation of much
condensation within the clothing system underneath the microporous samples. The condensation however, could not easily be removed from the clothing system because liquid water could not travel through the pore network of a microporous polymer. The condensation had to re-evaporate to travel through the pore network. This re-evaporation process required heat. In this system however, heat was not readily available because the rain provided a continuous cooling effect. Since no heat was available for re-evaporation, the condensation built up within the system. This further increased the thermal conductivity of the system, which led to additional heat losses. The viscous circle of events therefore rapidly continued eventually resulting in moisture vapor transmission ceasing.

Example explanation of how bicomponent membranes, like Paclite, work in the rain:

The structure of the bicomponent samples used in this study ensured that the hydrophilic layer protected the microporous layer and hence, any condensation that formed was in contact with the hydrophilic polymer. The transport properties of the microporous polymer were therefore, not impeded as occurred with the 100% microporous sample, and as such, the air within the micropores ensured that the samples conductivity did not rapidly increase. Less heat was therefore lost from the system, when compared to the other two types of waterproof breathable fabric, as was shown by the larger temperature difference that was maintained across the sample. The vicious circle of events were therefore slowed and more water vapor was transmitted.

[Stephen Seeber]

Hi Richard:

You provide no citation of someone (I presume) else’s research.  This little snippet does not prove a general point and certainly does not support the numbers you originally provided.  The condition described in the 1st paragraph would potentially prevent vapor transfer in Gore Pro or any PU microspun such as Neoshell, Futurelight or Ascentshell because of the vapor pressure differential available in the example. Concerning diffusion:   Phillip Gibson considers vapor transfer through microspun membranes a diffusion process.  You may want to check this paper that he co-authored:  “Transport properties of porous membranes based on electrospun nanofibers”.  You can find it on line.

If you would kindly provide citations for your statements, I will be happy to continue this discussion.

 

[Richard Nisley]

 

[Richard Nisley]

Stephen,

Gerry V asked a question about rain jackets that  (must provide DURABLE waterproofing). We both answered it. I responded because 1) I know a lot about the subject based on both primary and secondary research plus 2) he was respectful in his forum interactions.

Your interaction in this thread’s post starting with ”You provide no citation of someone (I presume) else’s research… is the opposite of item 2) and merits a response in kind.

The only primary research you have provided for evaluating a WPB garment is a standard hydrostatic head test and a proprietary MVTR test. You have never done a C6 DWR life test nor a microporous MVTR test in actual rain to support your otherwise groundless claims. Neither have you provided any peer reviewed scientific studies  to support them.

Relative to your statement, “Proper garment maintenance should avoid failure of DWR.” I ask myself is your material omission that it is not DURABLE a lie or just ignorance of the facts. Contrary antidotal evidence can be found searching for the term “wet-out” in the BPL forums (including from me), Andrew Skurka’s web site or the Section Hikers web site. Shortly after the DWR fails, the breathability goes to zero for microporous rain gear only. I also provided you the lab test procedure that clearly proves both points (1. the fluorine spikes in C6 will stay laid down after about 3 hours of hard rain and would require a dryer to reactivate them and 2.only in microporous rain gear, the breathability will stop when the DWR stops working.)

In summary Gerry V asked for rainwear recommendation that (must provide DURABLE waterproofing). I purposefully didn’t address a later microporous leakage mode in this thread because it wasn’t relative to his question. It was a binary decision for him: would his microporous or his bicomponent option keep him dryer, in the rain, for a longer period of time (aka DURABLE waterproofing).

[Stephen Seeber]

Hi Richard:

I have simply asked you to cite the source for the studies or figures you use without attribution.  If my logic or knowledge is faulty, I will read the studies and learn from it.  On the other hand, if your claims seem erroneous, we can have that discussion.

 

[Jimmy Legs]

Richard, you stated “Paclite will experience a ~ 25% breathability (MVTR) reduction after the DWR stops working. In contrast, AscentShell, will experience a ~ 100% reduction after the DWR stops working.” This is very interesting.  I assume Pac-Lite plus would be the same? I did not realize that any dwr wpb fabrics retained significant breathability after wet out.  In another thread I asked about my upcoming thru hike of the CT during monsoonal season.

Since I just missed out on the last Outdry Featherweights in my size, I’m wondering what would be a good rain jacket.  I have an older version Montbell Versalight with pit zips.  I’m trying to decide what would be better:  a wet-out Versalight with pitzips vs wet-out Paclight Plus with no pit zips…  Unless the PacLite would perform significantly better, I’ll probably just go with my Versalight.  Thoughts from the BPL community?  Thanks!

[Richard Nisley]

Jimmy Legs,

The specs on your old jacket were:
2.5-layer DRY-TEC™ technology
(Water resistance: 20,000mm, Breathability: 15,000g/m2/24hrs)
15-denier Ballistic Airlight rip-stop nylon

That is a non porous hydrophilic membrane. After wet-out, it will still maintain about 50% of its original breathability. I don’t see any compelling reason for you to upgrade to Paclite Plus if the venting is adequate in your existing garment.

[Stephen Seeber]

Richard, as usual, did not provide a citation for the study he cites as the basis for his conclusions.  The unattributed  quotes are from this paper: Moisture Vapour Transmission Through Waterproof Breathable
Fabrics Under Conditions of Rain by Gretton, et al.  This paper can be found on line and downloaded at no cost, which I did.  This appears to be a well constructed test and I am not calling its result into question.

In the  cited study, a PU microporous membrane is studied along with two other types of WPB fabrics.  Richard uses the results of the microporous membrane results to reach conclusions about a PU microspun membrane.   We have no information on how the thermal conductivity, vapor transmission characteristics or air permeability performance of the test fabric compares with a PU microspun membrane such as the AscentShell.  I suspect it is a leap of faith to apply the results of the PU microporous membrane to a membrane with very different construction and chemistry.

In the cited study,  this test was conducted at a single set of conditions.  The quantitative results will apply only to the conditions of the test:  91.4oF water, over which the test samples were installed, 41oF ambient temperature with 65% humidity.  <span style=”text-decoration: underline;”>The results of this test apply to the single set of conditions that were in place.</span>  If we hold the ambient humidity constant and reduce the ambient temperature, the condensation inside the garments will increase.  At some point, I expect the differences between the garments would disappear.  This would certainly happen when the inner surface temperature of the garment reaches 32oF. and the condensation freezes.  As ambient temperatures increase, condensation within the jacket will be reduced and the performance differences between the test fabrics will change.

It is well  known that moisture vapor transfer for  hydrophillic membranes and bicomponent  membranes with a hydrophillic component are significantly impacted by vapor concentration and temperature.  As temperature goes down vapor transmission is reduced.  As vapor concentration goes up, vapor transmission increases.  More can be learned about this  here: EFFECT OF TEMPERATURE ON WATER VAPOR TRANSPORT THROUGH POLYMER MEMBRANE LAMINATES by Phillip Gibson.  The lesson from this paper is this: The seemingly advantageous  performance of the hydrophillic and bicomponent membranes studies in paper cited by R. Nisely  may not be present at other conditions which will be experienced in real life use.

The OP is seeking a winter jacket.  In cold winter conditions, the DWR performance may become less critical because the wearer will be subject to snow, not rain.  Assuming some insulation layers are worn under the jacket,  the jacket interior temperature will be closer to the exterior ambient temperature than in the case of the test results.  Thus, in real life, the point at which the performance differences between the test fabrics disappear or are reduced is dependent on a variety of variables that the single values of 0 and 50% suggested by Richard Nisely cannot begin to explain.

In the cited study, DWR was applied to the fabrics in a secondary round of testing.  The performance of the fabrics all improved.  The authors said this about DWR:  A good water repellency is therefore essential for the transport of water vapour under conditions of rain. The water-repellent finishes that are used on waterproof breathable fabrics are continuing to improve; however they do not remain effective for the lifetime of a garment. It is therefore, important for chemical manufacturers and fabric manufacturers to continue to work together to further improve water repellent finishes. However, it is also important to educate consumers into looking after their waterproof breathable garments. Dirt and softeners will always have a detrimental effect on water repellency and hence, consumers must understand the need for and benefits of sensible washing, thorough rinsing, tumble drying and reproofing.

In summary: 1) There is no evidence that the performance of the PU membrane in the cited study can be applied to a fundamentally different type of membrane that is AscentShell. 2) The performance in the cited study will obtain under the conditions of the study and the performance will change under alternative conditions. 3) Performance of hydrophillic and bicomponent membranes will change substantially as water concentration and temperature conditions change. 4) Maintain your DWR treatment for best garment performance. 5)  All WPB membranes will have performance limitations.  In the cited study, no samples leaked.  Rather vapor transmission characteristics change.  If you are getting wet from the inside, slow down or change your layering and get the best WPB for your expected activities and conditions.

I stand by my initial reply to the OP.   However, I am very fond of my current Montbell Versalite for my winter activities in the Colorado Rockies.    It is a good value for its feature set and provides excellent protection from the elements.

 

 

 

[Jimmy Legs]

Thank you for the advice; I’m going to stick with the Versalite.

[Richard Nisley]

Another glowing review of microporous rain wear breathability WHEN IT ISN’T RAINING https://www.theinertia.com/gear/gear-test-the-north-face-futurelight-holidays-shopping-brigandine-purist-freethinker-mens-womens/

[Jeff McWilliams]

So what’s the takeaway from all of this?

Four years ago, permanent beading surface jackets looked like they were going to be the wave of the future.  Now Columbia’s Outdry Ex Featherweight appears to have been dropped from their lineup.  Their next lightest jacket is the Outdry Ex Blitz, which I think weighs in around 12.5 oz, though I can’t be sure where I got that number.

From Gore, the only viable option for a backpacker seems to be the Gore H5 Shakedry.

If one didn’t want to pay roughly $380.00 for the H5 (gasp!), but were concerned about breathability after wetting out, is Paclite and Paclite Plus the next best thing?

 

[Author]

Posts