Best Insulation System for Cold Rainy Mountains

Hold on, why would he be soaked in his fleece? He won’t be wearing it while packrafting. If his rain jacket wets out then he needs to treat it or buy a new one before the trip. Lastly, if he’s sweating enough to soak his fleece under his rain jacket then he needs to take it off and just wear a thin base layer under the rain jacket. If you have good rain gear and know how to manage your sweat production then I wouldn’t plan your garment purchase based on how it performs when soaking wet.

hosier …

let me say this simple fact for folks who havent been in the freezing soaking non stop rain for days

shiet happens

All it takes is leaving a zipper slightly more open, tripping on crossing a creek (and they are much higher and faster in those conditins), or strong winds blowing heavy rain into your shell

in warmer temps or less frequent rain you can make up for mistakes

in the freezing non stop rain conditions, you really cant … There is no sun, there is no drying, everything is saturated

you need to assume that you WILL be soaked at some point

if you are truly skilled and lucky you may be able to stay just damp

but if yr out enough eventually you WILL get soaked

;)

BEWARE of “grid” patterns on the inside of synthetic fleece base layers if you keep it on more than one day. The grid will mark your skin and make it itchy as he!!. I had to turn my gridded base layer inside out by the 2nd day due to my forearm “grid itch”.

I prefer various weights of fleecy polyester base layers for different temperatures. For sleeping I like a thin base layer (used only for sleeping).

I think I replied about this before, but this is not true.  If it’s marking your forearms, it’s too tight.  That means it doesn’t fit or is cut too tightly.  That means the problem is fit or cut, and not something inherent in the nature of the grid pattern.

“where in the world will the moisture go???”

Most of the moisture will be evaporated by the heat of the body, especially during exertion and so it phase changes to vapor.  Wicking helps, but is not the prime driver of this process.  It does help to have a fabric that doesn’t retain as much moisture within the physical material itself. But what helps most, is to have an outer garment that protects from the rain enough, but with enough air permeability to allow the most vapor dispersal as possible.  The traditional rain garments that you constantly recommend, are extremely poor in this latter area (which is why i spend so much time and thought on trying to improve this).

You contradict yourself, on one had you say the Cap 4 type baselayer is “THIN” as a fault, but then recommend a thin, wicking, quick drying baselayer.

Well, the original Cap 4 happens to be thinnish, quick drying, and fairly wicking, but also with more dead air space (if there is a midlayer,  and especially a windshirt or rain jacket on top) and thus greater potential warmth than the typical type base layer, especially when wet.  

It’s “win win”, which is my point and the point of how it was designed.  For those reasons, is probably why Richard Nisley referred to it as the most effective/efficient baselayer so far (paraphrased).

As far as what you want to put on top of a Cap 4 type baselayer, well i agree with you, fuzzy fleece of all kinds, but especially polartec thermal pro is great stuff.   Have at it, preach it from the rooftops brother, you’re preaching to the choir here, though i have some testing to do with reticulated (dry fast type) open celled foam sandwiched between mesh and very breathable nylon (unfortunately, winter ended sooner than i wanted or expected).  Apex similarly sandwiched between very breathable layers is decent too, and that i do have experience with.

Oh, and don’t assume i don’t have experience with cold rain or lots of it at a time. I live in the south east and do the huge majority of my hiking–especially backpacking in the latter fall, winter, and early spring and lots of cold to freezing rain is quite common during that time frame, and i have been out in it though not in a thru hike kind of way.  I happen to be much more tolerant of the cold, than i do the ridiculously hot and humid weather we commonly have from mid spring, summer, and early fall around here.  Apparently i’m keeping in tune with my Scottish Highlander ancestors.

Nor is it “theorizing” to understand or apply basic physics knowledge. There is a branch of physics called theoretical physics and not too surprisingly, it’s quite theoretical, because it deals with unknowns. The physics principles involved in all this, are simple and well known and accepted. A thin layer of mostly stilled air space, is going to be more comfortable and warmer on the skin when the fabric is otherwise wet, than a fabric that has more material touching your skin. There is no rational, sane arguing or debating with the physics of that.  However, according to Nisley and/or the research he has looked at and/or performed, generally speaking, it doesn’t seem to matter too much what the baselayer is or isn’t, as most of them ultimately end up with same or similar body core temps after activity and rest time.  Perceived comfort seems to be the major difference.  However, what is not clear, is what the testing parameters were.  Were they soaked with cold water in a cool and humid condition, or just wetted out with body sweat, etc?

I once had someone here tell me that a Cap 4 turned inside out was warmer and better that way. when active.  I tried to gently explain to them that this disagreed with the physics of it, but it seemed to fall on deaf ears.

Once something becomes part of a belief system for a person, it’s sometimes mighty hard for them to change their mind, even with the most clear and holistic logic laid out step by step.

+1 to what Rob P wrote.

my .02 system for wet AND cold would start with a very lightweight syn base layer- the lightest I’m aware is the 80 g/yd OR Echo- under 4 oz in long sleeve and Large. Moves moisture nicely, dries quickly and if need be can be wrung out almost dry.

I like a plain jane 100 wt fleece as a mid- layer on the move. The lightest I’ve found is Montbell’s Chameece. It’s pretty fuzzy, so decently warm- also retains some warmth when damp (also can be wrung out pretty easily)

for an insulting layer in these conditions, I’ve become a Polartec Alpha convert- can be packed and unpacked w/o much  consequence, unlike other syns. I have a couple, but for light-my Marmot Isotherm 1/2 zip @ 9 oz gets the nod.  I use a lot of down, but if it’s going to be wet I prefer syn

3 layer rain jacket and pants; lightweight ones-round things out

Justin

there is NO passing through LIQUID water from the inside to the outside in constant freezing rain

the moment your warm body vapout hits the shell cooled by freezing rain in 100% humidity it CONDENSES …

especially with slick 2.5 L wpb inner surfaces this form a wet sheen which you cant “breath” through

if you know anything about WPB fabrics you would know they work on a humidity and temperature differential 

they work best when the outsude is COLD and DRY

when its wet they really dont work too well …. And when you nice Cap4/T2 has been cooled and soaked by that sheen and by all the DWR failure and water ingress … All of which will eventually happen in non stop freezing rain …. There isnt much temperature or humidity differential

this isnt some BPL theorizing …. Come up here in dec, jan and even dayhikes in the freezing non stop rain can be dangerous

this dec and jan we got > 400-500mm each month … I think there were perhaps 3-4 days where it didnt constantly rain each month

;)

So much passion. It’s there any common ground on what to wear in cold wet conditions?

I’m looking at a new lightweight shell.  2 layer gtx Paclite or 2.5 dryvent, but that’s another thread.

I usually carry a fleece pullover and a down vest or jacket for camp or really cold rest breaks.  I’ve wondered how my system would perform in constant rain.  Always considered my tent/tarp/quilt add separate sleeping clothes as the ultimate emergency backup if soaked.

I like wool for sleep clothes, but synthetic for hiking baselayer.  Given the consensus that shells won’t breath well in cold and very wet conditions, does it really matter which synthetic baselayer our fleece you have?

Bob for a Goretex layer check out the Dynafit GTX Traverse on backcountry.com. I got one recently so if you’re interested PM me and I’ll fill you in on details.9.2 oz for 3 layer GoreTex seems like a good deal.

Thanks for all the replies guys. I think I’m going to order the Montbell fleece and probably a down vest to try out. That combo will certainly work for the summer in the U.S. Rockies. Up north it seems to rain longer so I might swap out for a synthetic vest.

Bob

theres an easy way to test it out … Next time its raining hard simply toss your layers in the tub soaking em, give em a quick wring and go walk around in the rain with em …. Carry dry layers and insulation in a pack to be safe

what youll probably find out is that heavier denser base layers simply retain more moisture … When yr soaked base layers dont do anything, there is no wicking

the only thing that works when yr constantly soaked (other than  neoprene) is fluffy and fuzzy … The fluffier and fuzzier the better

the brits use pile and pertex, yanks and canucks use fleece ..when yr constantly soaked the in

If it aint fluffy and fuzzy … Then it doesnt matter if its synth, it might as well be wool or cotton …

because in the freezing rain you simply arent drying it out and that wetness will be pretty close to your skin

im not talking about merely damp or even moderately warmer wet conditions, but soaked in the freezing rain

unless you take off your layers and wring it all out there is simply no where for the water to go

not all synth or fleeces are equal in all conditions

grid fleeces are superior for damp higher output activities where conditions allow for em to wick away moisure and they arent totally soaked

however once they are totally soaked and the conditions dont allow for the moisture to wick and evaporate (evaporate in the freezing rain? Hahaha) the thinner denser fabric and the snug fit will keep the wetness close to the skin than a looser weaver, fluffier fleece

the other thing about a cap4 that makes it less than ideal for truly wet conditions …. It has a 8-9% spandex content

;)

The US Special Forces are trained to not adjust any layers when saturated; just simply “walk dry their issued clothing ensemble in 30 minutes or less”. Their clothing ensemble consists of a polyester base layer, a fleece mid layer, and an Epic windshirt. They are also trained to only wear rain gear (either WP or WPB) for static environments.

Richard

most of us poor BPLers arent up to the same physical standards as those special forces folks … If any BPLer immersed themseles in 33F water for 10 minutes then  tried to walk it off soaking wet please raise their hand, ill admit to be VERY impressed

not to mention they wear fuzzy fleece AND primaloft over their grid fleece

does their immersion test include walking dry in the constant freezing rain?

i will say simply that if you use a T2/cap4 alone soaked even under a rain jacket youll get quite chilled in the constant freezing rain … And it doesnt dry out

Put on a thermal pro fleece (even a non high loft) instead and its a world of difference

were BPLers theres no way were carrying a grid fleece, a high loft thermal fleece, a prinaloft jacket, an epic windshirt AND a rain shell all at once … Tops and bottoms + a synthetic sleeping bag to make it all work

how much does that all weight anywayz

;)

The patagucci nano air feels decently poofy for it’s weight and it’s shell fabric is 40 cfm, maybe that would be better than standard synth puffies for drying yourself out?

^ Polartec Alpha I believe (or their variant – good stuff in my book :)

Eric I don’t expect to ever be “wring it out” soaking wet.  Too damp for down yes but not multiple fleece layers.

<span style=”line-height: 1.8;”>Capilene Lightweight looks like something I might wear a lot more often then Cap 4.  Maybe that with synthetic on top?  Last time I was fine with a T-shirt, long sleeve “safari” shirt and a rain coat. Probably. not best but I was warm enough. In the evenings I had a Patagonia Nano Puff.</span>

Hopefully I can get to the mountains some weekend to try some ideas out.

Thanks Richard  – I think for real world scenarios, I would trust the US Special Forces.

Oh Crap type of situations do happen.

Theres been many a times when i hear “but so and so does that”, usually some famous climber or such

the question i ask is can YOU do that …. Unless yr in the same physical shape with the same skills and gear, probably not

when dem kute kudlay seals practice their dynamic rewarming drill they have a very specific gear setup which includes thermal pro fleece, synthetic poofay, and eventualy a synthetic bag

https://www.sitkagear.com/insight/a-navy-seal-rewarming-drill

Most BPLer wont be carrying the same gear they do ….

the question i ask is can you dynamically rewarm in the freezing rain after jumping in a lake with the gear you normal carry?

my bet is that most folks here wouldnt be able to, myself included

Tried it once in more milder rainy conditions, everythibg stayed wet

unless you have a surplus of insulation (note they use both thernal pro high loft AND primaloft jackets and pants, not to mention a synth sleeping bag) you arent drying things overly

to believe that you can do the same as the kute kudlay seals with the gear you normally carry and without their physical capabilities is simply wishful thinking

Same as throwing on a pair of trail runners and climbing technical alpine peaks because you saw killian jornet do it

or free soloing big walls because you watched alex honnold do it

however i do encourage BPLers to go jump in a freezing lake and try to dry everything out walking it off in the cold rain … With the gear you normally carry

if you can actually dry it all out be sure to post up here

Richard and Eric,

I’ll fill in some details on Special Forces (SF) cold weather gear.  Special Operations Forces – Protective Clothing Uniform (SOF-PCU) is the current system issued to SF and the other SOF units.  Special Operations Personal Equipment Advance Requirement System (SPEARS) is the previous system.  Extended Cold Weather Clothing System (ECWCS) is the Army’s cold weather gear and the latest generation is essentially a copy of the PCU with a bit of SPEARS.

“The US Special Forces are trained to not adjust any layers when saturated; just simply “walk dry their issued clothing ensemble in 30 minutes or less”. Their clothing ensemble consists of a grid fleece base layer, a fleece mid layer, and an Epic or Epic/Primaloft outer layer depending on the temps.”

We adjust layers as necessary to keep our core temperatures up.  That could mean no adjustment when wet if the terrain (and tactical situation) allows us to move quickly enough to generate sufficient body heat.  It could mean changing or adding layers if we have to move slowly or sit still.  The grid fleece is actually the mid layer.  The base layer is either PCU Level 1 or SPEARS Layer 1.  PCU 1 isn’t very popular (it has a zipper against the skin) so SPEARS 1 was still used by SF.  ECWCS Level 1 reflects this as the Army went with SPEARS 1 instead of PCU 1.  I think PCU 1 and SPEARS 1 are Polartec Power Dry (if I’m wrong and the Natick guys see this thread during morning coffee, please correct me) but I can’t be certain because there are no Polartec labels.  ECWCS 1 does have Polartec labels.  The high loft fleece jacket is PCU Level 3 and the Polartec Alpha jacket is PCU Level 3A.  PCU Levels 4 -7 are various types of shells.

“They are also trained to only wear rain gear (either WP or WPB) for relatively static environments.”

We wear whichever shell is necessary to stay warm.  In practice, that means the WP layer, PCU Level 6, is worn more often when it’s not raining – either in high wind or snow.  If it’s warm enough to rain, then a shell probably isn’t necessary (we are usually moving quickly and generating a lot of body heat).  While moving, the WP layers are used more often for the snow.  That seems to be a big difference between SF and the civilian backpacker.  We use Gore-Tex jackets and pants routinely for movement in the snow (makes you a rocket if you fall during downhill skiing).

“not to mention they wear fuzzy fleece AND primaloft over their grid fleece”

Base layer, mid layer grid fleece, fuzzy fleece or Polartec Alpha, and then shell.  Only the Level 7 high loft shell (for extreme cold) is an additional layer of Primaloft on top of the fuzzy fleece.

“does their immersion test include walking dry in the constant freezing rain?”

That particular suck fest is meant to simulate falling through the ice – not freezing rain.  It’s not unlike your bathtub test.  So we know the capabilities of our gear – that kind of thing.

“i will say simply that if you use a T2/cap4 alone soaked even under a rain jacket youll get quite chilled in the constant freezing rain … And it doesnt dry out”

I’m sure you’re right about drying out but the rain jacket should keep you warm even though you’re wet.  In freezing rain, I delay putting on my rain jacket as long as possible so that I can move quickly (I pushed this too far once and by the time I stopped to pull my jacket out of my pack, I had a hard time figuring out how to open my ruck – so I was dipping into hypothermia).  Once the Gore Tex jacket is on, I’m always warm.

“Put on a thermal pro fleece (even a non high loft) instead and its a world of difference”

I’m also a big fan of fleece jackets.  I often find that no shell is necessary even with wet snow falling as long as I have my Level 3 jacket on.

“were BPLers theres no way were carrying a grid fleece, a high loft thermal fleece, a prinaloft jacket, an epic windshirt AND a rain shell all at once … Tops and bottoms + a synthetic sleeping bag to make it all work”

We only carry the PCU layers that we think we need for a particular mission.

Hope this was helpful.

Kris

I agree with Eric on the fluffy fleece like the Patagonia Synchilla. It is less dense than 300w Polartec and very breathable. Coupled with a wind or rain shell, it puts 60g jackets to shame and is great to sleep in. Over the years LL Bean, Woolrich and Russel have made knock-offs of the Synchilla Snap Tee, so you might find used bargains there.

Patagonia has the R3 gridded garments now and they show promise in the cold and wet arena. I used a Mountain Hardwear hight loft gridded fleece jacket this winter with excellent results.

If you want to try an R2 type fleece, the military versions are a super bargain.

I outlined in blue the relevant “cold-rainy”  US Special Operation Forces layers. Their recommended layers are a polyester base layer, a fleece layer, and their Epic windshirt if moving. If static, their recommended outer layer is either a WP or WPB.

should point out that in addition to III, they have recently also included IIIA which is Polartec Alpha

I reserve my Alpha like I would reserve my down insulating layers, BUT unlike down I can also use it on the move if need be and unlike other syns, it can be packed/repacked w/o near the loss of loft- it is slightly less insulating than some of the other syns- weight for weight, but I think that advantage goes away  from Primaloft, others after several packing/repacking episodes

Richard, that isn’t correct.  I think you might be getting your information from civilian manufacturers that are marketing clothing lines based off of the SOF-PCU.  I have never heard of Adventure Tech but the “A” in front of “PCU” tells me it’s not official issue.

The layering isn’t based upon moving or being static.  The entire purpose of the PCU is to be modular.  We pick what we want to use based on a number of factors of which movement is only one.  Temperature and moisture are just as important.

I don’t know anyone that uses the windshirt.  It’s seen as just a less effective shell.  And even when not moving, in most circumstances there is no need for either WP or WPB.

For those looking for a pared down take on a high loft thermal pro fleece, the Rab Boulder pull-on looks good if you can find one. I was able to find one on ebay but they seem to be otherwise scarce. Half zip, chest pocket, and listed weight is 13.4oz in medium.

Wow, great thread and great contributions….thanks to Richard N., Kris, Eric, Justin etc.  I have way too many questions, but anyway, here goes:

Kris:  How heavy is your grid fleece mid layer?  Is it like Patagonia thermal, mid or lightweight (the newer versions of the old cap 4, cap 3 or cap 2).  Or heavier than all of these?

Eric/Dale:  When Eric was talking about “fuzzy” fleece I kept thinking of Synchilla, which Dale mentioned.  Any other thoughts on Synchilla for these applications, both regular Synchilla and Lightweight Synchilla?

Any thoughts on the new R3 for applications like this?