DWR stands for Durable Water Repellent and is the coating used on breathable but waterproof outerwear. All of my raingear is a few years old. If you’re riding in the rain like I am this week, you may be discovering that your DWR raingear is not has durable or repellent as it used to be.
DWR coatings don’t last through too many washings unless you use cleaners specifically designed for use on DWR fabrics. It eventually wears out.
Some DWR coatings can be ‘refreshed’ by simply tossing it into the dryer. The heat of the dryer reactivates the water repellent property of the fabric. After a while, though, you must reapply a new coating.
Factory DWR surfaces are probably a fluoropolymer coating of some kind. Replacement fluoropolymer sprays are products like Scotchguard and Granger’s Spray On Waterproofing. This stuff works well but some fluoropolymer’s have the unfortunate property of breaking down into suspected carcinogens. I don’t personally use these products.
The easiest waterproofing, in my opinion, are silicone sprays like Kiwi Camp Dry. Silicone sprays work very well, in my opinion. Unfortunately, with silicone waterproofing you loose some of fabric’s original breathability.
The brand favored by outdoor enthusiasts is Nikwax, and it’s what I sprayed on my pants, jacket, shoes and backpack tonight. Nikwax is a wax-based polymer. I sprayed Tent and Gear Proof on my backpack and *ahem* on my shoes, and I used Nikwax Spray on my jacket, rainpants, hat and gloves. The biggest problem with Nikwax: Some of the sprays stink like strong vinegar, and the odor persists for several weeks after application. Nikwax also has wash-in repellents but I’ve never tried those.