Airsoft Action May 2020 | Page 48

KIT & GEAR TECHNICAL FABRIC MAINTENANCE micro-climate inside your clothing system helps to prevent either too. The body regulates itself effectively; as activity levels increase you sweat and the evaporation of this moisture helps to cool the skin. If moisture is not allowed to move away you will become “uncomfortable” inside your clothing system. Letting moisture escape from the system is a tricky thing but it’s essentially what is being discussed when we use the word “breathable”. Behind it all is a law of nature: the Law of Partial Pressures. This law states that moisture as a vapour will naturally move from a warm, high pressure environment to a cooler low pressure one. If we are keeping a well-balanced temperature inside our clothing system, then on a bad-weather day moisture will move away from our skin through the pores in our clothing and escape to the outside. Sometimes we call this the “Temperature Gradient” as it sounds like moisture vapour is moving “down” from hot to cold. So does a breathable fabric technology work in a rain forest? Yes, is the answer but due to the temperature inside the garment and outside the garment being more in equilibrium, the transfer rate will obviously slow down. We all know we can work with Ma Nature - but never beat her! This, of course, is also subject to testing. Many methods can be used here to establish a Moisture Vapour Transmission Rate (MVTR) or a Resistance to Evaporative Transmission (RET) figure. Of the two I prefer an RET figure as it just plain makes more sense to me. Skin is 100% breathable and has an RET of Zero. As soon as you cover it though, you build up a resistance that slows down the rate at which moisture can be transmitted away; the thicker the barrier the more resistance and the slower the transmission. In essence, this means that as you cover the skin with layers your system becomes less breathable so we will always be looking for technical fabrics with as low an RET figure as possible. In some cases the clever folks at Gore have got the RET figure well down into single figures, especially on their bespoke technologies. They continually develop completely new and innovative lining fabrics which are thinner (but more durable) than the industry standard linings available elsewhere - and thinner = less resistance, right? WHAT YOU CAN DO IN YOUR DOWNTIME If you’re spending a lot of money on a set of waterproof gear, then you really want to get the best out of it don’t you? Just like changing tyres or the oil in a car, your “shell gear” will really, really benefit from some regular “TLC”, a bit of a service if you like. I truly believe that there is a far better understanding of the fabric technology used in our clothing systems than ever before and it’s a subject that is a bit of a “holy grail” for me. All too often I’m out on the range or at a game with my mates and when we get back in the car their “Gucci” waterproof shell gear just gets dumped unceremoniously in a pile on the floor or in the footwell! These are usually the self-same people that I will see at a later date bemoaning the fact that their expensive waterproof jacket “isn’t working”, complaining to all and sundry that somehow the technology has failed and that they are wet and uncomfortable. The most common gripe I hear is that “this funking thing is leaking” when actually it’s still perfectly fine and the fact is, it just isn’t “breathing” anymore! Like all performance items, top-end shell gear needs maintaining regularly to get the best from it. You might only change the tyres on your car infrequently (probably when the MOT or insurance inspection rolls around!), but on a Formula One car they may change the tyres several times during a single race to get the very best performance. When you buy a Gore-Tex (or similar) jacket you’re investing in a high-performance item, and as such, it needs treating like one! Over time things like the hydrophobic (water-heating) Durable Water Repellent (DWR, think a microscopic “film”) on the outer face fabric of the garment will begin to wear and crack and the fabric will start to hold the water that’s now allowed through to it. As new, water droplets will be held on the DWR layer, simply rolling off the fabric before they penetrate. You’ll notice after a while that this “beading” process will start to lessen and that the water is being absorbed into the fabric itself; this is usually noticeable first in areas like the shoulders where pack straps or a plate carrier rub and abrade the DWR, or on cuff ends where the fabric rubs against itself. Internally over time, body oils, grease and general dirt will also build up and the net result is that your jacket will stop “breathing” as well as it did when it was new. You won’t really notice this until it becomes obvious and water vapour that was previously being transferred out of the system stays inside and re-condenses. You’ll feel cold, clammy and uncomfortable and, when you put your hand inside your jacket, feel “water” and of course your quite natural conclusion will be that the jacket is leaking! A re-proofer will restore the waterproof performance of your gear to ensure it continues to keep you dry and protected. To combat the degradation of performance you simply need to give your jacket (or pant) a bit of care and invest in a maintenance product. There are many of them “IF YOU WERE TO SIT ON A WET, FLAT SURFACE THE MEAN PRESSURE YOU GENERATE IS AROUND 10,000MM! IF YOU WERE KNEELING IN A FIRING POSITION THEN THE POINT OF THE KNEE GENERATES 15-17,000MM OF PRESSURE…” 48 MAY 2020