Gore Tex, What is it? How does it work?
Gore Tex 2L vs 3L ever wondered what the difference is?
This is from Peter Glenn Sports and demonstrates in a very simple and concise way how Gore Tex works in theory and also the difference between 2L and 3L tech.
Everything here is just a suggestion, I strongly recommend you follow the directions on your clothing before attempting any of these instructions.
This is not an exhaustive list but will help you to understand what your clothes are doing. And how to get the best performance out of them, through proper maintenance.
You don’t take your board down the slopes for an entire season on one wax, so why should your clothes be any different? Maintenance makes your gear last longer, perform better and keeps you more comfortable. This leaves you to worry about what run you are going to take next. Instead of if you can stay warm and comfortable enough to last that lift up the mountain again.
Gore Tex Care
The pores are so small that even your sweat(liquid form) can block the pores, it is very important to keep the gear clean as dirt will block the pores and negatively impact the breathability of the fabric. Things as simple as the oil from your skin or sunscreen will block it up as well, so it is very important to clean regularly as you use the gear.
As with any garment, follow the instructions on each one to understand the best way to treat them, as a guide however:
You are ok to machine wash at warm temperatures with detergent but no fabric softener, make sure it gets a good rinse cycle to get all the dirt out of the pores.
Contrary to what you may think, most Gore Tex gear will actually benefit from a Warm Tumble dry if the DWR is not performing up to par. It helps by reactivating the treatment on your clothing (make sure that your gear allows for this!).
As stated on the wiki
Both wear and cleaning will reduce the performance of Gore-Tex clothes by wearing away the Durable Water Repellent (DWR) treatment on the surface of the fabric. The DWR prevents the face fabric(external facing) from becoming wet and thus reducing breathability. However, the DWR is not responsible for the jacket being waterproof. This is a common misconception, so when the face fabric becomes soaked due to an absence of DWR, there is no breathability and the wearer’s sweat will cause condensation to form inside the jacket. This may give the appearance that a jacket is leaking when it is not, but the DWR is still crucial to the best performance of any membrane-based waterproofing. It can be reinvigorated by tumble drying the garment or ironing on a very low setting. If this does not work, re-proofing the garment by applying a topical water repellency restorative (DWR treatment) for outdoor fabrics can be used. Wash-in re-proofers are not recommended for this use, as they can hinder the garment’s breathability. They coat the inside and can prevent liquid passing out of the garment.
Understanding the technology
Gore Tex is by itself not waterproof, it has a Durable Water Repellent (DWR) layer, they together make the product both breathable and waterproof. This is also the reason the seams of gore tex are taped. This is the waterproofing that protects you from getting wet.
The most common issue for gore tex is that the DWR layer wears away over time, you sweat underneath the fabric or dirt clogs the pores. When this happens, your sweat accumulates instead of moving through the fabric and can give you a wet feeling that is mistaken for a loss of waterproofing in the clothing.
Breathability is measured by how much water vapor passes through a fabric in a 24 hour period(measured in grams per square meter), the maths is (g/m2/24hrs), or just g depending on the way a brand labels it. This rating can vary anywhere from the low ratings such as 5k, up to 20k and beyond.
Waterproof Rating: You could get 5k, 10k, 20k or more, but what does it all mean?
This rating for gore tex is usually significantly higher than other fabrics, this can be 20k all the way up to 60k. Most of the time Gore Tex won’t claim a waterproof rating because they guarantee its waterproofing.
But what do all these figures mean? 20k is a Hydrostatic head of 20,000mm, the hydrostatic head is the height of a column of water that produces enough pressure to force water through a material. This means that in 20k gear the column of water must be 20 meters high to lose waterproofing. This is why Gore Tex can guarantee waterproof rating, there is no way anyone is pushing water through that under reasonable circumstances.
The only time water seep can be a problem is either, when you are sitting on a lift chair and your weight is enough to force water through, or the most common. You are sweating too much or have lost your breathability and your sweat is accumulating inside.
2L vs 3L
Gore Tex can then be labeled as 2L or 3L, this refers to the inner layer of the jacket ONLY. The outside of both are NO DIFFERENT.
To understand this better, let’s look at the layers:
From the outside, which is your membrane layer, you then have your nylon layer to protect the jacket (this can be thick or thin). The third layer(3L) is the mesh laminated on the inside to protect the wearer from rubbing against the membrane. 2L doesn’t have this layer instead, it has a loose lining instead to protect the membrane.
This means you have a trade off, 3L will be more durable but 2L will be more breathable. However, the loose lining will make 2L warmer but 3L can in a lot of cases have a fleece lining. In the end it comes down to your personal preference, don’t think 3L is better just because it’s a bigger number. Your needs dictate the most suitable product.
Understand that Gore Tex is a brand, not a product.
Anyone can make gear licensed under the name and technology. Also, the patent for this is now expired so companies are free to use and tweak it as much as they like. As such you will see a lot of other brands making similar fabric products and you shouldn’t necessarily think that Gore Tex is better.
It’s possible that their product was in fact made with the Gore Tex technology but slightly tweaked.
Here are some links to official Gore tex articles, as always, the recommendations may not apply to your gear so be certain it allows machine washes and ironing and so on, BEFORE doing it.
I hope this gives you a little more insight into the technology that is Gore Tex, helping you to make a better decision on what product you are going to buy.
Gore Tex Care Center
Gore Tex Wiki
PDF Breathability Tests
A comparison of Membrane vs Gore tex as well as conduit, sympatex, lowe alpine, nextec, schoeller, titanium