To measure the “waterproofness” of a particular fabric, the testers would stand this long glass pipe on a sample fabric, then add a measured amount of water—say 1000 millimeters and let it stand 24 hours.
Professional anglers like Gary Roach can’t let wet weather hold them back or divert their attention all season long.
I bought my first “hi-tech” raincoat with money I earned bailing hay for local farmers when I was in high school. It featured a nylon camo outer fabric bonded to a PVC lining and cost more than I’d earn in a week hoisting bales.
I couldn’t wait for my first rainy-day duck hunt. I knew the ducks wouldn’t see me and the rain couldn’t touch me. How’d that work out?
I spent far more time in my duck blind on rain free days, but I managed to be wet on every hunt. To hide from the ducks I wore my camo coat every hunt, rain or shine, not realizing the sweat and water vapor exuding from my skin was being trapped inside my waders and coat just as efficiently as the PVC material would keep those November raindrops from penetrating into my layers of clothes inside.
At the time there was no such thing as an all-weather coat capable of keeping a person dry in a rainstorm while being comfortable wear for work or play on dry days. Manufacturers tried, for sure. Plenty of outfits were available with strategic vents designed to allow puffs of the moist air inside to escape through flaps on the back or vent holes in the armpits.
There were attempts to make non-waterproof fabric waterproof. Some used spray-on chemicals (think Scotchgard) or products such as paraffin wax to imbue waterproofness with a modicum of breathability. In general, as waterproofness increased, breathability declined and vice versa.
Then came Gore-Tex, named Gore after its inventor (Bob Gore) and Tex for textile, not Texas or a play on the term high-tech. Still, Gore-Tex is high tech and was the first textile made to be both waterproof and breathable. The concept is simple.
A drop of liquid water is jillions of H2O molecules clumped together. Water vapor is individual molecules of H20 atoms floating around in the air. Liquid water evaporates to become water vapor; water vapor condenses to form liquid water. Gore-Tex fabric has microscopic pores in it large enough that individual H2O molecules—water vapor—can pass through easily, but clumps of H2O—liquid water—are so large, they can’t squeeze through the nine billion pores per square inch in the Gore-Tex membrane.
Rain gear will keep you dry on foggy, dewy mornings even when the chance of precipitation is slight.
When it was introduced in 1977, Gore-Tex was a game changer in the quest for waterproof/breathable (W/B) material—for rainwear in particular and outdoor garments in general. And they were expensive! My “state of the art” raincoat probably cost me about fifty “hay-bale” bucks. The first Gore-Tex raincoats debuted at four or five times that price and a pair of pants or bibs to complete the suit wore similar price tags.
The rainwear industry learned avid outdoor people were willing to pay the seemingly exorbitant price for rain gear that worked. Some manufacturers tried to duplicate the performance with similar technology, but the Gor-Tex fabric’s patent stymied much of the success. Leading outdoor apparel makers just paid Gor-Tex to use the Gore “textile” in the coats, hats, pants and other waterproof products they produced.
Many still do, but the Gore-Tex patent expired in 1997 and ever since, rainwear makers have copied, designed, hybridized and layered multitudes of similar (or supposedly similar) W/B features into the products they sell. Some employed their own version of the W/B membrane, impervious to liquid water but with microscopic pores to allow water vapor to pass through. A few utilized special fabrics or fabric treatments designed to perform similarly, all with the same purpose—to make their garments waterproof and breathable.
The reality is, however, none of these fabrics (including Gore-Tex) are as water-proof as rubber or plastic, but how water-proof are they? There are both general and technical standards. Originally (pre-Gore-Tex) it was simple. Rubber and plastic was waterproof, most everything else was water-resistant. A tightly weaved fabric would shed a few drops of rain, but a steady rain would soak through quickly—resistant to a degree, but not waterproof.
With today’s garments, it’s not so simple. Clothes labelled “water-resistant,” will still leak quickly, but don’t think a rain coat marked “waterproof” is going to keep you totally dry permanently.
Some waterproof gear is not much better than a water-resistant garment. Some is almost as good as rubber. How can a rainwear buyer judge? Brand A and Brand B can both be marked waterproof, as can even model X and model Y from the same company but none of them are equally waterproof. “Waterproof” is only a general level of performance.
Special laundry products for modern rainwear can extend its life and improve its performance.
An industry standard is now gaining acceptance in the rainwear industry. The standard is based on a rather goofy test developed in the United Kingdom but it’s better than nothing.
THE UK TEST
I’m sure there are now machines available to run the test, but the original test equip-ment started with a one-inch diameter glass tube 10,000 millimeters long (about 33 feet.) To measure the “waterproofness” of a particular fabric, the testers would stand this long glass pipe on a sample fabric, then add a measured amount of water—say 1000 millimeters and let it stand 24 hours. If it didn’t leak through the cloth, they’d add additional water to increase the pressure on the fabric. At some point, the increased pressure from adding more and more water would make the fabric leak. Whatever that water level (in millimeters) the material can endure without leaking for 24 hours is its waterproof rating. Since most people don’t instantly understand what a rating of say, 1500 would be, the “standard setters” grouped the results into more understandable categories. If a fabric leaks with 1500mm or less in the water column, it’s classed as water resistant. To be sure, a 1500mm cloth would be highly water resistant compared to just a nylon jacket, but also know most outdoorsmen would be disappointed with a rain coat that tested 1501 which could be classed as waterproof. According to this test and rating system, fabrics which test 1501mm to 5000mm can be called waterproof. If a material tests between 5000mm and 10,000 it can be called “Very Waterproof” and above 10,000mm the fabric is termed “Highly Waterproof.”
When I’m out on a rainy day in an open boat, I want “highly waterproof.” The Gill Winter Angler Jacket and Bibs I wear ice fishing and in very early season open water fishing are rated to be a minimum of 10K. Later in the spring, when winter and summer seem to be battling over the Great Lakes I switch to my Frogg Toggs FTX Armour rated at 15K. Whether it’s a sudden downpour or all day drizzle, I’m dry under my ‘Toggs.
ANOTHER TEST
Of course the waterproof rating is only half of the comfort factor. Total “waterproofness” (like rubber) is possible but it comes with zero breathability. Water vapor won’t penetrate rubber or plastic. So the scientists at international standards facilities came up with the term Moisture Vapor Transmission Rate (MVTR) to describe how much water vapor can penetrate a breathable waterproof fabric.
There are testing machines for this as well. The concept is simple but making the actual measurements are complex. I’ll try to explain the simple part.
Since both air and water vapor can penetrate breathable fabrics. a MVTR tester has two chambers divided by whatever breathable fabric is being tested. One side contains air with a Relative Humidity of 100%. The other chamber is filled with completely dry air—RH of zero. If the fabric was removed, the moist air and dry air would mix almost immediately. With the fabric in place, what the MVTR machine measures is how fast the moist air mixes with the dry, expressed as how many grams of water vapor can pass through a square meter of the breathable membrane in a 24-hour period.
You’ll often see Capt. Mike wearing a set of Gore-Tex lined bibs to protect him from wind, wet or fish slime.
The specifications on my Rapala Pro Rainsuit has a MVTR of 8000 (meaning 8000g/m2/day) which is great for most fishing activities. If you are rowing a drift boat, have to hike a good distance to the water’s edge or engaged in some other somewhat strenuous activity causing you to break a sweat, or if wearing raingear on a day warm enough for you to just sweat more than normal, look for a higher MVTR rat-ing, perhaps 10,000 or even 15K.
MORE THAN MEMBRANE
A drawback of the waterproof/breathable membranes used in rainwear is that none of them are very tough. To start with, the membrane is very thin. The garbage bag you use in your kitchen is about 10 times thicker than Gore-Tex or other W/B membranes. The membrane is not tough, either. It can easily be ripped, snagged or abraded. So there’s no such thing as a waterproof/breathable garment that’s made only from the W/B membrane. The membrane is always bonded to some sort of cloth to give it strength and more.
Every coat, parka, top, bottom, boots or other product is produced with an outer layer designed to protect the W/B from the environment in which the product is designed to be used. The top layer in a hunting coat is likely to be covered with a tight weave of rugged nylon fabric to ward off or deflect brush and briars. Fishing rainwear doesn’t need to be quite so tough.
The fabric making up the shell of a layered W/B rain coat or pants is also infused with a product called “DWR” for durable water repellant. DWR adds water resistance to the fabric. That means most of the rain or spray that lands on the garment will just bead up and run off, rather than soaking into the weave of the fabric. The waterproof layer under the outer shell never has to contend with the rain or spray that just sheds onto the floor of the boat.
Does is seem like using a DWR impregnated fabric to make the outer shell is akin to wearing a belt and suspenders? If the W/B membrane is so impervious to water penetration, what’s the need to have a water-resistant outer fabric?
For one, it aids the breathability of the garment. What if a raincoat came with the W/B membrane bonded to cotton denim? After a few minutes of rain, the blue-jean material would be soaked. The W/B material on the inside would keep the wet on the outside, but the sweat and water vapor inside would stay inside, blocked by the wet denim.
I keep a high tech, packable rain top and bottom on my boat all the times– just in case.
More important, since the W/B membrane is so fragile it’s inevitable that normal, regular use like sitting down, walk-ing, casting, stuffing the coat in a corner when it’s taken off, packing it in a suitcase when traveling—basically anything other than hanging in a closet—causes wear and tear on the membrane. Small cracks or holes can and will develop and those would be instantly noticeable in a downpour. With a good DWR infused outer layer, most of those wear-defects stay undetectable for years.
NOT SO DURABLE DWR
Actually, with use, the DWR deteriorates faster than the W/B membrane. If you have a high-tech coat or bibs that develops a leak, blame both the shell and the membrane. But unlike the membrane, the DWR can be rejuvenated.
Many manufacturers suggest a heat treatment, either by putting the rainwear (dry) in a warm clothes drier or warming the outer shell with a clothes iron. I’m sure it works some of the time, perhaps most of the time, but does it work time after time? The only way to find out is to wear it and hope the heat treatment did the job.
What I’ve been doing with my W/B outer wear for the past several years is a two part treatment using Nikwax products. Most of time, when fishing, I need to launder the tops and bottoms long before any problems with the DWR occur. As a charter captain, I handle every fish that comes aboard and clean most of the fish that are caught. In the spring and fall, I wear my W/B gear as a windproof outer shell daily, rain or shine, and after several trips, they are usually well slimed and need to be laundered.
So rather than reactivating the DWR with heat, I rejuv it with every laundry cycle. Most rainwear comes with washing instructions. Follow those instructions if you can still find them; but if not, the laundering suggestions for all of my rainwear suggests some variation on washing with warm water then either hanging to dry or tumbling them in medium heat.
Instead of regular laundry detergent which can affect the DWR, I use a product called Nikwax Tech Wash. It’s advertised to be gentle on DWR or even revitalize it. It probably does. Instead of hoping the DWR is revitalized, I run the rainwear through another wash cycle using Nikwax TX.Direct.
Insulated W/B hunting parka and bibs kept this angler warm and dry on a snowy, early season outing.
The TX.Direct adheres to areas where the DWR was less durable and worn away, reinfusing the material with water resistance. Duo-paks of Tech Wash and TX.Direct are available from Amazon and other places where Nikwax products are sold.
THE INNER LAYER
Almost all W/B garments come with an inner liner under the W/B membrane—and don’t buy anything that doesn’t. I’ve seen a few pieces advertised as “microlight” with-out an inner lining. No doubt eliminating the inner lining does reduce weight or bulk to a degree. To the manufacturer, however, it makes the product as much as one third cheaper to produce. To the purchaser, unless a few ounces of weight or tiny packed-size reduction is highly important, don’t buy it. With zero protection, the membrane will wear out substantially sooner than later and there’s no way to rejuvenate it.
Instead, look for an ultra-lightweight outfit. I have a highly packable rainsuit made by Whitewater that I keep on my boat or pack in my luggage for away-trips. Both the outer shell and the inner lining are very light weight, but the Whitewater still delivers 10K waterproofing and 10K breathability. The jacket and pants will each pack into separate, softball-sized stuff-sacks.
My other, slightly heavier rain suits all come with a heavier gauge inner lining material. Even then, I doubt the lining adds up to more than ten percent of the overall weight. What the heavier liner does do is improve durability and allows for easily accessible pockets to be added inside the coat or bibs to provide better protection and easy access for phones, cameras or other gear that needs to be kept dry.
Many hunting parkas and bibs, as well as my Gill Winter Angler Coat and Bibs, replace the thin, inner lining with an insulated inner lining. You can bet that’s what I’ll be wearing for those first trips after ice-out right on into May for cold weather comfort as well as waterproofing.
Much of the rest of the summer will find me in one of my lighter rainsuits, at least at first light. The pants keep my butt dry if I sit on a dew-wet seat and the top keeps me dry from any spray while on the trip to the fishing area. Both serve as a wind breaker to ward off the morning chill.
If you shop wisely and take care of them, you’ll never regret the money you spend on modern, hi-tech W/B clothing. Think of them as your insurance to staying warm, dry and comfortable every time you head out on the Great Lakes.
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