Waterproof?

Me, pressure testing a Nookie Assassin suit, back in the day.
I loved that shirt, wonder where it is?

Waterproof Breathable Fabrics (WBF's) are these days regarded as essential in outdoor clothing. In a previous post I gibbered on incessantly about the breathability aspect - now we're going to talk about waterproofness and how the two figures are expressed.

If a manufacturer quotes the fabric performance it will usually be as follows:

XXXX/YYYY

 - which is waterproofness (or WP or Hydrostatic Head) / breathability (MVP or WVT or similar)

Typical figures for a waterproof garment are 10,000 (mm) / 5,000 (g/m2/24hr)

The waterproofness figure in this case, 10,000mm, means that you could put a 10m column of water on the fabric without it leaking, or that you could take it down 10m underwater.  Sounds a lot, eh?

The truth is you aren't going to be even 1m underwater very often, but that pressure could be simulated by the hydraulic pressure of being hit by a wave, for instance. And nobody really knows how much of that we are exposed to. However, experience has shown that anything with a WP rating of over 4000 doesn't really leak at all in use. And that's lucky, because what the manufacturers never tell you is that the seams are not as waterproof as the fabric. 

Your garment is full of seams, and they are tape sealed to make them waterproof. The quality manufacturers use a water pressure testing device to check their fabrics and this can also be used on the seams - generally speaking seams pass the test if they withstand 4000mm pressure. Seams tested in the factory are very unlikely to withstand more than 8000mm, and in any case it's not desirable to test this high on a production garment because of the damage that kind of pressure inflicts on the fabric and seam. 

So, irrespective of fabric rating, straight out of the factory the real waterproofness of your garment is closer to 4000mm, but that's OK - it's more than enough. However, over time repeated flexion of the seams will weaken the adhesive and lead to a constant deterioration in waterproofness. This can be repaired at home with glue, tape or patches until it becomes too laborious to do so, at which point it's time to replace the garment. How long this takes is entirely dependant on usage and care - a pro boater like one of our test team who paddle almost every day might arrive at this point in three months. A recreational user might take three years. It's impossible to say.

Thanks to Ardmel Automation Ltd, The University of Life, The A Level of Intuition, and a GCSE in Making Kayaking Equipment for 20 Years.

So how does fabric breathability really work?

Is it really possible for a fabric to keep the water out while letting perspiration escape at the same time?

Good question... 

I originally wrote this article for the Nookie website, and it may have appeared in Canoe And Kayak UK magazine as well. It's reared its ugly head again because I was doing some research on sailing gear recently, and some of the comments on the forums amused me - it was like stepping back in time. 

Back when I first became interested in technical outdoor gear, it was still a widely held belief that waterproofness and breathability were inversely proportional. A lot of ocean sailors and fishermen seem still to believe that, while yet bleating about how wet they get inside their oilskins from perspiration!

There is a mechanism by which a waterproof material can still allow water vapour to pass through it. The physical chemistry of this is fairly horrendous so I'll gloss over it and say that it's called diffusion and was defined by a clever chap called Fick, and you can read what he worked out here if you want your head to hurt a lot. The way a waterproof barrier can be made to allow diffusion varies and is even more complex than the inner workings of Fick's mind, but they fall broadly into two categories - microporous and hydrophilic. Both types of barrier allow diffusion but microporous ones being a bit more natural do so fairly simply, following Fick's hypothesis to the letter. Hydrophilic barriers have an anomalous diffusion mechanism, using transient hydrogen bonding of water molecules to complementary functional patterns on the polymer chains. It is sometimes described as a ‘‘molecular stepping-stone mechanism’’ but I think a better way to visualise it is that the water molecules are passed from one place to another like a bucket passed along a line of people. You don't want to know how though... you really don't! 
Luckily for us both of these methods work pretty well. But, how breathable do the fabrics need to be? Well, truth is nobody knows. We can work out how much vapour we need to shift at a given workload. But estimates of how much of that is lost through the head, or on the breath, vary enormously. And the laboratory tests that indicate how much vapour will pass through the fabric per unit time are, frankly, a bit rubbish.

WVT (water vapour transmission) is technically (SI units) expressed in kilograms (of water) per square metre per second. However, the so-called "trivial unit" of grams/m2/24hrs is the more common measure of breathability in industry. The figure that the manufacturer gives, however, is obtained in a laboratory test rather than under true biological conditions. There are at least three International Standards that can be applied to WBFs, each using different test conditions and expressing results in completely different ways. The ‘‘sweating hot-plate’’ method, called  the skin model (ISO 11092:1993) was developed from research into the effects of clothing on human thermoregulation under varying workloads, and yet the Standard test parameters (35˚C; RH 100% to 40%) are pretty meaningless for outer garments worn in real-life situations.

The problem is that the barrier doesn't just breathe on its own. It requires a vapour pressure gradient between the inside and the outside. And that depends on temperature, relative humidity (RH, above) and a bunch of other stuff. You could force yourself to understand Fick's hypothesis at this point, or you could just believe me. Either or...

Just because a fabric has a high breathability score in a lab test, doesn't mean it's an oustanding performer in the field. Because in the field the figures are all substantially different. And we wear one or more layers of thermal clothing, the performance of which is as or more important than that of the waterproof shell! In many wet conditions, the thermal and vapour pressure gradients across the actual waterproof fabric are negligible, so any vapour transmission will be approximately nil too, irrespective of any other performance characteristics. But the manufacturers have to say something, so they quote what they can. There is, however, no substitute for human testing in real operating conditions, and this can reveal surprisingly excellent performance even in counter-intuitively difficult circumstances. In some conditions, a good waterprooof breathable shell CAN expel all the moisture we need to for thermoregulation, and be dry inside at the end of the day. I recommend strongly that you test garments before buying, or buy something a trusted fellow has used and liked, or at least buy from a manufacturer you can trust, rather than one that quotes spurious and irrelevant lab results in an attempt to garner your interest.

Before I go, a few myths to dispel. Microporous fabrics DO NOT leak, or clog up with salt. The diffusion process CAN reverse and breathe backwards, but if the circumstances for this persist for more than a few seconds you are probably already dead or something very weird. The fabric being wet or frozen DOES NOT in itself stop the diffusion process, and can in some circumstances accelerate it. And the fact that other gear like a spray deck/skirt, buoyancy aid/pfd, or backpack are covering vast swathes of the breathable area may not help, for sure, but it DOES NOT completely stop the fabric from breathing there.

So, there you go. That's breathability. Check back soon for a rant about waterproofness. See ya!

Thanks btw to the Royal Society of Chemistry, The University of Life, The A Level of Intuition, and a GCSE in Making Kayaking Equipment for 20 Years.

Behind The Scenes 2

I should know by now that time and tide wait for no man - photo Bjorn Thomassen

   Another of the lifestyle DPS's (Double Page Spread) for the Haynes Kayaking Manual featured a cheerful group of sea kayakers, ostensibly setting up camp / making a brew in a picturesque rocky cove. These lifestyle pics are part of a strategy to make the book "feel" good throughout, to tie together the 400 or so action shots and the less dynamic equipment photos. There are only six of them, but since they run full-bleed across two pages each, they have a big impact on your first impressions of the book when you pick it up. I judged this to be important, but time will tell whether it makes the positive difference I'm hoping for...

© Haynes Publishing Ltd - photo Bjorn Thomassen - Valley Sea Kayaks

The location, a gully on Cot Valley beach in Cornwall, was chosen by photographer Bjorn Thomassen for its spectacular rock formations and gigantic mega-pebbles. Less so for its for ease of access while manhandling composite sea kayaks, as there is no path into the gully, but we are no strangers to adversity. As well as the four of us in the photo, there was just Bjorn, assisted for the day by awesome Swedish photographer Jeanette Svensson. But as always everyone just mucked in and lifted and carried stuff. And there was a lot of stuff. Portable studio lights from Elinchrom and The Flash Centre. That's three Elinchrom Quadras with their diffusers and stands, plus two giant folding California Sunbounce reflectors, battery packs, cameras, spares, stuff to keep it dry... Frankly it wouldn't have been possible to get the job done in the tide/weather window of about six hours without the super-portable power packs and lighting equipment, unless we'd had a separate rigging team.

The Valley Sea Kayaks and bags of Nookie gear had to be ferried down steep rocks onto the beach. Normally I'm one for throwing these durable kitbags wherever possible, but by some bad planning I wasn't sure which bags contained photographic equipment as well as clothing! And the kayaks themselves, though far from fragile, are too valuable to scrape and drag. So getting everything to the location took a while, although not as long as paddling there would have done. In another twist of fate, we were all in bare feet. I'm really not sure why that happened, and suspect incompetence on my part. I can see at least one pair of shoes in the final photo! Sometimes there is just too much to think about...

Model Chanelle, completely unfazed by being used as a porter

The Kayaking Manual has been on the streets for over a month now, and bandied around the various social media for longer than that. That photo is, so far, the only image that I've received significant grief over. Some paddlers felt that the models looked too tanned, warm and happy, and that this didn't reflect their idea of kayaking. And a couple of people thought it was a bad thing that they look like models. Sorry... The thing is, all four of the people in the shot actually are models. The fact that three of them also happen to be kayakers is kind of by the by. They were selected for the fact that they look outdoorsy and sporty, but more importantly that they can stand stand around all day getting windblown, wet, cold and hungry and still be able to smile and look good!

Models Russell and Jade also did the lifting and carrying

Some other comments:
 
'...a bit too fake for my taste, perfect hairdos, spiffy clean clothes, shiny kayaks, even the rocks are clean...'

'I would not have my composite boats on rocks like that...'

"...none of my friends and I go on a trip with coordinated tops and shorts."



That last one did amuse me a bit, because most of my friends do ;)

Interestingly, The Expeditioners Magazine sent a positive message about how much they liked the photo when we shared it on Facebook. Perhaps because they too are real kayakers, but as committed as I am trying to make travel look attractive and not like some sort of trial...

Russell takes the plunge...

 Of course, part of the mission was to feature the boats from Valley Sea Kayaks and the neoprene and thermals from Nookie. I can't get all the photos for a book like this without the help of sponsors. That's why everyone's wearing matching gear - it all comes from the same manufacturer, and the sub-plot here was to get them some catalogue shots in return for the equipment. The paddles are all from the German manufacturer Kober. The boats, while all Valley, have a bit more variety, but I still don't understand the criticism that they're "too shiny". My boats get dusty and muddy in the back garden, but they tend to get very clean in the water.
What these pics really show is the massive difference between photos of how the location really looked (mine) and the ones Bjorn lit carefully with the Elinchrom gear and shot on the top cameras and lenses from Canon. It's like pumping a little magic into the shot. And that's what I wanted... I do understand the criticisms of those who'd prefer to see grittier pics, perhaps of unhealthy looking people being cold and miserable, but I don't think that's going to sell as many books! That's it until the next instalment. Have fun, and don't forget to breathe.

Models look on as Bjorn positions lights and kayaks. Look at the difference in light and texture in the next photo!

Another of Bjorn's shots from the same set that was used in the back inside cover spread of the book. I love all the different compositional elements of this photo, it's more of an art shot than a lifestyle one.

Val Sesia Kayaking 2013

I won't be there. Last year was a hoot - sunshine on green and white water, and good friends from the kayaking industry that I hadn't see for a while. It was my first time at this annual gathering and I thought of making it a regular fixture, but this year other work and social commitments take precedence. I'll be thinking of all you crazy people hucking in the sun, though, and leave you with a little composite from last year, my first time on the Egua, but I hope not the last.

Photos © Josh Gosling & Big Dog Kayaks

Warm up advice

I recently published an article in Canoe & Kayak UK about fitness and training, and the response to that has prompted me to share some of the advice from it here, too.

If you paddle a kayak, especially in the UK where it's a bit chilly a lot of the time, you are probably guilty of getting in the boat without doing any kind of physical preparation. Maybe you think you can ease into it by paddling gently at first. But the forces of nature might have other plans. So... 


Warm up and Stretch
I never did bother with this when I was younger. And I was injured a lot. I also found that after thirty minutes in the boat I was starting to get tired, because I was fighting cold muscles and unyielding tendons. By the time I was properly warmed up, it was game over. 


I was worn out from battling against my own body. I thought I was really, really unfit, but I wasn't. 

I was just doing it wrong...

It takes ten minutes of gentle exercise like fast walking, jogging, star-jumps or whatever you like, if you're a teenager. If you are middle aged I would suggest thirty minutes of even more gentle exercise than that. It's a massive drag and I never feel like doing it, especially as it cuts into my actual boating time, but it does help a lot.
Stretchy power bands like those pictured here are a really good warm up strategy that you can use in the car park (attach them to the roof rack, or a tree) and won't make you feel too much of a loon!
 
Having warmed up, do a range of basic stretches on dry land. Google them, I'm not a trainer!

Finally do some rotation and forward and backward stretches in the boat. This has the added advantage of making sure your range of movement in the kayak is unencumbered and that there's nothing in the cockpit that is likely to injure you. That reverse cross-deck rotation is a good way of checking you've screwed the drain plug in, too...

If you do this, I'm willing to bet you'll enjoy your paddling more, and be far less injury prone to boot!

Behind The Scenes 1

One of the tricksy things about creating a book like the Haynes Kayaking Manual is to captivate the reader from the outset with fantastic imagery. The words may well be entertaining and informative, but you just aren't going to buy it unless a cursory flip through the pages ticks all the right boxes!
At the planning stage, I was pretty confident that I was going to shoot high quality technique pics (I hadn't planned for the British weather, but that's another story), and I knew from the start that contacts in the kayaking industry would help out with mindblowing action pics. What I felt was missing was a bit of lifestyle to tie the message together, a few shots that said "Kayaking is fun, cool people with happy lives go kayaking..." And strangely that's more of a challenge. A wicked action shot looks awesome as long as it's basically in focus and correctly exposed - no one is too worried about the composition and the finer points of lighting. But unless a lifestyle shot is super-über-mega-well executed, it will end up looking like someone's holiday snaps, and that does not stand up to scrutiny in a book on the shelves in Waterstones.

© Haynes Publishing Ltd, photo Bjorn Thomassen

 I didn't want to go overboard with this strategy - out of 500+ photos in the book, I just wanted about six completely posed lifestyle scenarios, interspersed through the book, enhancing the feel. All the rest of the shots are "live" action, with the exception of a few headshots of kayaking personalities that I interviewed. But to get those six I was going to need an exceptional shooter. I considered a number of photographers, but the obvious choice was Bjorn Thomassen. I'd seen all kinds of different work from this globe-trotting maestro but what always stands out is his exceptional use of light and the magical "texture" he gives many of his shots. He's really in demand, so I wasn't sure I could get him on board, but when I visited him at his studio in Cornwall he revealed he was a keen kayaker himself, and was almost as enthusiastic about the plan as I was!
The photo above is the chapter opener for the surf kayaking section. The surf's a bit messy, but I think the image successfully conveys warmth, and happy sun-tanned people enjoying a balmy tropical evening? You'd never know it was shot in a howling gale and driving rain on a bitterly cold beach in North Cornwall.

photo © Simon Burfoot. Bjorn uses Elinchrom lights, Canon cameras/lenses.

 The twin Elinchrom Quadras light the models, utilising weatherproof and portable battery packs. The lights are carried here by Izzy Tulloch and Josh Gosling, while Bjorn shoots from the safety of his umbrella. Since the tide was rushing in, it was necessary for the whole scene to move back several metres between each shot - otherwise the flash units could have been free standing.

Bjorn briefs the models - in this shot the Elinchrom light has triggered from Simon's on-camera flash. ©Simon Burfoot

The combination of this highly portable and controllable system, and the high quality lenses and cameras from Canon, allows Bjorn to create an image where he, not nature, controls the quality and texture of the light, despite being far away from any power source.

Mattos, and Kitty James. Valley Surf Kayaks, Kober Paddles, Nookie Eqpt  © Simon Burfoot

 There were unique challenges for every shoot in this series. On this occasion, a very limited timeframe (for reasons of availability of models and the lovely British weather, the shoot was scheduled for late evening, and the crew had assembled from all over the UK) was compounded by the unseasonable cold. There's only so long you can look as though you're not freezing! But as you can see, we nailed it.

The crew assembles the gear and the models get ready to freeze. © Simon Burfoot

Shooting the other direction presents no problem when you've brought your own light! © Simon Burfoot

 

Big Dog Ad

The latest copy of Canoe And Kayak UK magazine contains this very fetching ad for Big Dog whitewater kayaks, using a photo I shot of Josh Gosling on the Egua river in Italy.

I was really pleased with the degree of freeze on the exploding water droplets here, and the colourful feel considering the amount of black gear in the shot.

The tough part of getting these kind of shots is just being there. It's not usually practical to hike in so you have to paddle Class 4-5 with a heavy waterproof Pelicase between your legs, then somehow keep the kit dry when shooting. There's a lot of clambering in and out of the boat in sketchy eddies and it's pretty tiring, but the reward is in the results.


Thanks to Big Dog kayaks, Kober paddles and Nookie softwear for keeping me afloat, and Lowepro bags for stopping my cameras getting granite rash, even when I do!