You walk into an outdoor sporting goods store.
"Good morning, sir and what can we do for you today?" a smiling young salesperson dressed in casual outdoors fashion, logo prominently displayed, greets you.
"I'm after a really good raincoat, for hiking in the bush."
"Then you're in luck, as we have a wonderful selection of the latest high performance gear," they grin, waving you away from the fashion section into the technical area. "Where are you going hiking?"
"Western Arthurs, Tassie. You know, the Traverse. Lots of tall, scratchy, wet bushes. Rains like ninety percent of the time. High humidity when it isn't raining. Mud, rocks, snow, the whole shebang. Need a good raincoat to keep me dry in that!"
Their grin takes on a slight woodenness, but they rally. "Oh yes, did that myself a coupla years back. Wonderful hike."
"Really? What coat would you recommend then?"
"This one would be perfect," they point out a suitably heavy-duty calf-length coat in a eye-catching blue. "I've had one for years and it's still as waterproof and breathable as the day I bought it."
"Nice," you say, feeling the durable fabric and noticing the eye-watering price tag. "Bit expensive." You heft the jacket. "Heavy too."
"Guaranteed to keep you dry, though," they point to the label. "And breathable, to let the sweat out."
"Well, that's reassuring. May I try it on?"
"Certainly!" they say enthusiastically, then a thought strikes them. "Um, are you wearing any insect repellant? Suncream? Sweat much? Had a shower recently?"
"Well, yes, it's high summer in Australia, of course I've got all the appropriate lotions on," you laugh. "Tropical strength stuff, the mozzies are hell out there. And I'm sweating like a pig too. Had a shower last night though. Why?"
Their grin falls a bit further. "Um, then I'll need you to put this coverall on first, I'm afraid. The permeable membrane in the jacket is a bit, you know, sensitive. To chemicals like DEET in repellant. Dissolves it. And oils and sweat and grime. Block the pores or something and it doesn't breathe so well." They see the disappointed look in your face. "All the brands are like that. Doesn't matter where you get your jacket. You have to take good care of your gear or it won't work properly."
"So I need to keep my skin away from it? And avoid lotions? And not get sweaty inside it?"
"Yes, that's right," they shift uncomfortably. "But there's this technical wash stuff and a DWR treatment you can apply to restore performance. Relatively inexpensive."
You note that the technical wash and DWR restorer together cost more than you spent on your last trip to a restaurant. "Uhuh," you grunt, unconvinced. "DWR?"
"Durable water repellant," they explain. "Environmentally safe. No fluorocarbons in this one," ignoring the fact that the PFCs are used during manufacture not restoration, and that manufacturers are still using PFCs, though they might be less harmful to the environment than they used to be.
"How durable?" you ask suspiciously.
"Half an hour?" they venture. "In wet scrubby bushes that is. If it's just drizzle, it'll last a lot longer than that.
"But it's a multi-day hike! I'll be bush-bashing for most of it and in heavy rain for a lot of it and..." You gather yourself. "What happens if the DWR fails, does it leak?"
"Oh no, but the breathability suffers a bit," they admit. "It feels as if it's letting the water in, but really, it's just that your perspiration can't get out as fast as you produce it."
"So I get wet?"
"Um, a bit dampish?"
"Cold?"
"Maybe?"
"Enough to be dangerous?"
"There's been no actual cases of hyperthermia that I know of," they claim, evasively and inaccurately. You note that they aren't familiar with the difference between hyper and hypo-thermia.
"I think I'll have to look elsewhere. This one doesn't sound suitable," you say, as an excuse to get out of the shop.
"Can I suggest this one then," they try desperately, pointing out an eye-wateringly yellow, square-cut garment cowering shamefully in the back displays.
"That's a plastic Macintosh!" you shout.
"It'll keep the rain out," they explain, waving their hands downwards as if trying to calm you. And if you take it off, it'll be breathable. Cost less too," they point out. "Doesn't need DWR either."
"Tell me, when you did the Arthurs, did you use that blue, waterproof, breathable jacket of yours? How did it go?" you ask hotly.
"Um, to tell you the truth, I don't hike much." They twist in discomfort. "Manager just told me to say that, to make the customer comfortable." They brighten a little, "I do have that jacket though. Liked the color. Staff discount."
"And you use it much?"
"Not really, it stays in the closet except when I need a coat to get to the bus-stop."
You start to edge towards the exit. "So, as long as I don't use it for anything serious, and as long as it doesn't rain much, it'll stay waterproof and let my perspiration out? As long as I don't perspire more than a little bit? So the guarantee is practically useless?" Moving faster now to get away.
The salesperson follows you a few steps, "Yeah, but it's a nice blue! Stands out in the bush if you need rescuing!" One last try for a sale.
"From hypo-thermia, probably, because the raincoat got me all wet," you mutter, being careful to not say "hyper" because you are just a little bit pedantic.
"Then can I show you some boots for your hike, sir? Waterproof and breathable? Guaranteed to keep you..." The door closes and cuts them off mid-pitch.
You swear to yourself just a little bit, then mutter, "Shoulda got that plastic Mac. Hard to find them these days..."
Sorry, We Could Do Better...
However, I am heartened by news that the various manufacturers are well aware of the shortcomings of their goods and are seeking better answers. E.g. Our DWR Problem - Patagonia and Outdry Extreme Waterproof Apparel & Shoes | Columbia Sportswear (though I worry about how durable that Outdry is, with the membrane on the outside! Might need to wear a jacket on top of it, like a yellow plastic Mac...)
Gore has released a single-layer breathable membrane material that is JUST the breathable membrane. GORE-TEX SHAKEDRY. No outer layer that needs a DWR. Sounds good. Permanent beading of water on the outer layer, maximum breathability. I wonder how durable it is? I suspect that bush-bashing with it might be a mistake... I saw one of the jackets in Kathmandu the other day. Very light, slippy feeling on the outside. Very expensive. Definitely not durable enough for bush-bashing.
Three Left Feet...
I once bought 3 pairs of the same boot in three weeks. It wasn't because I loved them and wanted more of them...
Over the years I've bought many, many boots, and since I became aware of the mythical 'breathable waterproof' boot in about the 1990s , I've been trying to find a pair. Thirty years later and I'm still looking.
So I bought a pair of Oboz Bridger 10" high tops, coming midway up my calves. They sported the tag "B Dry" referring to, I think, their permeable membrane technology. They fitted well and wearing them around the house they appeared to breathe OK. I took 'em for a multi-day hike in summer, in the Kosciusko National park in NSW. The hike encompassed tracks and roads and rugged bush and we tromped across high dry moors and low boggy bits and across a few creeks and went hunting for waterfalls. To my delight the boots seemed to do a pretty good job on the first two days.
Then I got a satellite phone message from my wife telling me that I needed to come home in a hurry because the Victorian government was going to shut the NSW border TONIGHT because of a COVID outbreak (this was in early 2021) We were at a hut near Mt Jajungal in NSW at the time and it was early morning and drizzly and we'd have to push it to get to the car. We had planned to be out for one more night. The path back to the car went through a lot of very wet grassy, bushy stuff and there was a bit of rock hopping and creek crossing and by the time we got to the car I noticed that the left boot was a wee bit dampish. The right one seemed fine though.
We made it through the border checkpoint with a bit of time to spare and then headed down the long road to home. The next day I inspected the boots and yes, the left one was noticeably damp. I gave them the bucket test, immersing both up to the ankle overnight. Yep, Lefty leaked a few tablespoonsful. Righty was tighty though. Now, I knew that the outlet I bought them from (Kathmandu) had a pretty good policy of accepting boots back if they didn't live up to their claims (because I had returned a pair of Salomon's for leaking previously) and in fact Kathmandu Holdings, who own the Kathmandu brand, had bought this small US boot manufacturer (Oboz) not so long ago so. When I took the boots back and pointed out the failure of the left boot, they happily swapped for a new pair.
Not to be disappointed a second time, I put the new boots in a bucket of water, submerging them up to the ankles, to see if they'd leak. They did. Even worse and again it was only the left boot! This time a whole cupful of water got in overnight. I took them back and they swapped them again, without any fuss. I repeated the test with the third pair and the LEFT BOOT leaked again! Even worse this time. Time to give up. The salesperson gave me a refund, after sharing a wistful joke about "If only one of the leaky boots had been a right boot instead, we could have made one good pair out of three tries..." It all left me wishing I had put up with the slight leak in the first pair.
I bought a raincoat from them with the refund. It's DWR failed me on a subsequent hike, and that was only its second trip. Sigh.
Alternatives
DIY
I have in the past used the idea of mixing up a blob of silicone sealant in turps and brushing that on to a fabric to waterproof it. One of my best (strongest, sturdiest, incidentally oldest) tents has been treated this way to re-proof its fly. It does add weight, so I wouldn't do it to a tent unless there was no alternative.
But I wonder if it would work to make a raincoat? Start with a simple cotton (or polyester) garment, siliconize it this way and what would you get? Apart from a coat smelling of turps, that is.
There are numerous Youtube videos showing people doing this to old bedsheets to make tarps, but would it work for a raincoat? Wouldn't 'breathe' to any extent (and does that even matter?) Would it be and stay rainproof? Hmm. Probably quite heavy...
Using SilNylon or SilPoly
I like this work from MYOG Ultralight Rain Jacket - Chilly Bin Hikes where she makes the raincoat out of a waterproof material (SilPoly). Not meant to be breathable at all. Lightweight and she customised it to her own needs, length, pockets (or lack therof), etc. Very light at 108g. I want one, but I don't have the skills.
One thing to look out for would be a design using SilPoly rather than SilNylon (which apparently absorbs a bit of water) (Chilly Bin uses SilPoly)
Off The Shelf
Maybe this one instead. Cagoule | Sierra Designs It's 100% nylon and doesn't pretend to be breathable. Though SilNylon (if it is silnylon) does tend to soak up some water. SilPoly would be better. See LightHeart below
OUTDOOR RESEARCH RAMPART MEN'S JACKET – The Wilderness Shop looks nice. Cheap! Somewhat heavier than the 100g in Chilly Bin's garment, but probably more durable as a result. Bit short though, would like longer in the hem. Combine with 'rainkilt? Bonus is that there is an outlet 'nearby'.
Rain Jackets - Sil - Polyester – LightHeart Gear Youtube review at LightHeart Gear Rain Jacket Review | Quality Where It Counts | Light Heart | First Look - YouTube Note to self. I'd take a Medium My chest size about 40 inches
A raincoat for your raincoat
Here's an idea. How about wearing yet another layer over your raincoat to keep it dry? Wait, wait, I know it sounds silly but hear me out. If the inner raincoat is really breathable, then having a fully waterproof outer layer to keep the rain from wetting out the inner coat might enable it to keep doing its job. Like a two wall tent. Of course the moisture from your sweat that makes it out into the space between the coats will condense and then proceed to wet out... Oh damn, never mind.
It does occur to me that it would nonetheless be useful to have a fully waterproof coat as well as a breathable one. In a bush-bashing situation the tough waterproof coat would work better and after getting thru the bush, the breathable one could take over. A bit like wearing pink rubber kitchen gloves (that don't breath but keep the water and half-frozen slush from soaking your warm gloves) when bushbashing thru wet scrub and then normal gloves (that can breath) when not.
Just take the damn raincoat off
There is an idea that a fully waterproof jacket is sufficient. You wear it when it's raining and you take it off when it isn't. Maybe replace it with a windproof jacket that breathes if you need to. All very well to say, but I've hiked thru conditions that you wouldn't called rain but which would soak you in minutes anyway. We call it fog, but it's more like soup. And then there's interminable drizzle. Just goes on and on and on all bloody day.
So that strategy doesn't work in every situation. Question would be does it work worse than a much more expensive breathable jacket that doesn't properly do its job? Tests have convinced me that even only moderately hard walking in a somewhat vented non-breathable raincoat will get you damp from sweat.
Walk wet- walk warm.
We had a saying back in the day before breathable raincoats were a thing. Dry Japara was the cutting edge (I've still got one!). "Walk wet, walk warm", meaning that OK, you'll sweat and get damp but the Japara would keep the cold wind out and stop you from getting absolutely soaked and very cold.
Always the experimentalist, I recently did a test where I wore a non-breathable jacket for a moderate to easy hike. It was a cool-ish day, probably never more than 20 C and rained lightly on and off, with short bursts of warm sunshine. Delightful, really.
The jacket kept the rain out as well as expected (much better than straight from the shop after I seam sealed it and fixed the storm flap and the hood...). However, unsurprisingly, if I left the jacket on for about half an hour, my shirt became wet from sweat, especially on the back where my pack pressed the jacket against my skin and there was poor air circulation. Interestingly, on the sleeves and front where things were a bit looser, shirt-wetting was much less noticeable. I could definitely feel the humidity inside my little portable sweatbox, but it wasn't uncomfortable. I can imagine that if it had drizzled all day and I had to keep the jacket on for hours and hours that I'd have gotten soaked from the inside. I'd have been warm though. A quick drying shirt with a spare dry shirt in the pack would have worked out OK. And here's the critical thing. Because I hadn't paid thru the nose for a supposedly breathable jacket but was still getting wet, I was much happier.
Don't sweat it
A lot of the problem would go away if we didn't sweat so profusely (and in my opinion unnecessarily) all the time. Why on earth are we sweating away gallons when it isn't hot enough to need cooling? Perhaps I just need a good anti-perspirant. (I've read that some people use them on their feet to stop ski boots getting soggy on the inside and ruining the insulation of the sox and causing cold feet.)
And another thing. Hoods
Here is that jacket before I 'fixed' it, not breathable, just waterproof, (well it is after I seam sealed it, wasn't before...) But look at the hood. What a load of garbage! It has no brim, nothing to stop the water either dribbling off the hood and onto your face or flying in on an angle into your face. It needs modifying!
So with a bit of thought, some McNett Gear Aid polyurethane (pu) adhesive/sealer and some wire and pu coated ripstop nylon, I made a fairly decent front porch for the hood and glued it on. Much better! Note extra storm flap too.
Storm flaps
Once I got that jacket properly waterproof and tested it in the shower, I found that water would run down my chest, under the storm flap onto the non-waterproof zip and then inside. Yuk. Taking a leaf from a much better jacket, I glued (using McNett Gear Aid Seam Grip ) another flap that would go over the zip and then fold back, all under the original storm flap, acting to bounce the water back out again. Worked OK! All storm flaps should be triples like this if the zip isn't waterproof.
I found an excellent (i.e. he agrees with me on most things) website maintained by Roger Caffin discussing raincoats and breathability and Australian conditions. It's at Rainwear (bushwalkingnsw.org.au) Roger is a legend and his words are worth their weight in freeze-fried dinners. Read his stuff!
Vapor barrier layering
OK, here's an idea I like because I have never ever had a session in the rain pushing thru wet bush when my Gore-tex jacket kept me dry (and more importantly warm) on the inside. They just don't breathe well enough and the DWR gets wrecked by the bush and the jacket wets out and then they really don't breathe well enough. Then my insulation layer gets damp and cold from sweat, even if the jacket isn't actually leaking.
Wear a thin easily dried shirt as base layer. Want it to feel warm even when wet and easy to dry, so thin is good. A hoody is great for more head warmth. Call this the base layer. Or the wet layer.
Put a thin, light, waterproof jacket on top of that. Like one of those disposable plastic rain coats. (Not a poncho, want sleeves and maybe a hood.) Call this the vapor barrier.
Put a medium fleece on top of that to keep you warm. Wear a wooly hat too. The inner waterproof layer should stop them getting soaked with sweat. Call this the insulation layer. Depends on how cold it is and how hard you're working what thickness this should be. In the Artic, real thick. In Tasmania, medium.
Put on an outer waterproof raincoat. Light, cheap, wind and rainproof. Make it tough enough for bushbashing. Maybe not a PVC plastic Mac (unless it is tough and light) but maybe a cheap polyurethane coated woven nylon. Not expensive Gore-tex or Event, or even NGX. Something that doesn't rely on DWR to be waterproof. Doesn't need to be breathable, but good luck finding anything well made that doesn't at least claim to be breathable even it if it isn't very. Waterproofness is key. Seam seal if necessary. Make sure it has a good hood and well protected or waterproof zips. Pockets are nice too. Call this the rain layer.
Go do some bushbashing in the cold and the wind and the rain.
If you warm up too much from exertion, um, not sure what you can do about that... Take it all off down to the wet layer and enjoy the rain? (Bush would destroy the vapor barrier...) Take off insulation layer maybe? Or use a thinner one?
When get under shelter, peel everything off, towel your torso dry, put on a warm base layer. Put your fleece back on, it should be dry.
Wring out your damp base layer and hang up under shelter but in wind, to dry. Turn wet vapor barrier inside out and hang up too. It should dry fast. Some materials drain the water to the bottom of the garment when hanging so a wring out of the bottom every now and then speeds things up.
Use the now dry vapor barrier over your dry base inside your sleeping bag for extra warmth and keeping bag drier?
Repeat each day for a week. Use the probably still slightly damp wet layer. when walking if it is still raining. Otherwise hang it off your pack to dry.
You can use similar idea for keeping socks dry and feet warm. Wear long vapor barriers to keep rain and puddles from getting into your midlayer socks even if your boots get soaked. Use non Goretex boots that are well ventilated so they dry out faster.
Send me a message telling me how it all worked and then maybe I'll try it out... Any volunteers?
OK, fine, I'll do it myself. I chose Lycra for the wet layer shirt. I've got loads of from running and I'm used to running in it when it's soaked with sweat. Doesn't feel too bad and dries relatively fast.
Vapor barrier was one of those plastic raincoats from the $2 shop (Used to be $1 shop, but you know, inflation...) Very light, packs very small, not very robust. Has a hood and sleeves. (but more about the sleeves in a minute) I didn't use the hood or a hat, too warm for that when running.
For the insulation layer I used a Haynes Underarmor shirt. I've had two of these since I saw then on sale and thought they'd be a great idea. Trouble is they aren't great for anything. The first time I used one on a run, it was too hot in the sun and too cold in the shade. Anyway, they are slightly thicker than Lycra and might make a good insulative layer if I can keep them dry. I had trouble keeping the vapor barrier sleeves in place between the wet and insulation layers and eventually just let them ruck up around the biceps so that the lower arm didn't have anything between the wet and insulative layers. They were gonna get wet. In the real world, bashing thru wet bush sleeves get wet anyway from water running back from the wrist-hole even when wearing a raincoat.
For the rain layer, I chose good old fashioned nothing. It wasn't raining. Now, you might wonder why I would bother testing this if it wasn't raining. Good thought. I was interested in how it would feel to run in a wet plastic bag and how much sweat I'd generate and what would happen to it.
On my legs, I just had running shorts and bare legs. And runners of course.
Then, on a nice, cold but sunny day I spent 2 hours running up two moderate hills and around a lake. 20K distance and about 500m elevation in all. Not very fast, but certainly enough to make me sweat. Oh boy, how I did sweat. 2 liters in all, which is typical for this run for me, so not more than without the vapor barrier but certainly not less. Why would it be less? Because some people who want you to buy their expensive vapor barrier shirts make the claim that the skin senses the moist micro-climate and sweats less. Yeah. No.
So, what happened? Well, where the vapor barrier covered the wet layer, the insulation layer stayed dry. Where it didn't (sleeves and bottom of shirts) it got damp.
Wet layer didn't feel clammy, surprisingly. Tick that box.
I stayed warm and could definitely feel the difference in warmth on my dry torso from my damp arms, which felt cooler. Tick that box too.
Biggest 'surprise' is that my running shorts got absolutely soaked! Of course, all the sweat from my torso dribbled down under the vapor barrier through the wet layer onto them. In the real-world usage, I'd have to wear rain pants and make sure not to tuck the shirt wet layer and shirt vapor barrier into them so the water would run down the outside.
This also made me realise that all the times I've cursed my so-called waterproof socks and boots for letting in the water in the rain was probably because the water dribbled down my legs into the socks under my rain pants. Need some waterproof cuff at the top of the socks to prevent that. Having the rain pants over the boots is fine to make the water on the outside stay out perhaps, but not the sweat on the inside.
Take-away from all of this is that the method has some merit, that I'd have to be careful about channeling sweat all the way down the outside of my boots and that the bullshit that some of the vapor barrier shirt selling people carry on about sweating less because of the micro-climate is just that, bullshit.