DWR stands for Durable Water Repellent. DWR is designed to repel grease, oil, dirt, and of course water. DWR is not a permanent treatment, to increase the longevity of your waterproof gear you need to regularly wash and reapply DWR.
Before you go through the trouble of washing your gear and reapplying DWR, make sure you need a new application. To see if you need a new treatment go outside and spray water on your gear. Check to see if the water “beads up” on your gear, next pick up your gear, and see if the water falls off.
Check to see if there are any dark spots where water was absorbed or anyplace water did not bead/ fall off. If your gear seems to be working, congratulations, you don’t need to re-apply DWR.
If your gear isn’t performing as well, as usual, it’s time for a new DWR coat. Here are the steps you need to properly re-apply DWR. Each piece of gear is different so make sure you look up how your manufacturer recommends washing and drying the gear.
1. Wash and dry
2. Reactivate the DWR
3. Check DWR
4. Re-Apply if necessary
Wash and Dry
Look at your manufacturer’s instructions and wash your rain gear. Washing your gear gets rid of the dirt, oil, and grease your garment has accumulated over its lifetime.
To help protect your gear further it might be a good idea to buy a laundry detergent specifically designed for technical fabric. After you wash your gear dry it according to the instructions specific to your gear.
Reactivate the DWR
Now is time to “reactivate” the DWR currently on your jacket.
Again your manufacturer should have specific instructions on this. But this step will most likely involve applying heat to your garment. This could be in the form tumble drying your garment, using an iron, or warm water.
After you “reactivate” the DWR test your gear again to see if another coat of DWR is necessary. Sometimes reactivating the DWR is all your gear needs.
There are multiple ways to reapply DWR and you guessed it, your manufacturer may have a recommended method. The two main methods are Spray on and wash in.
Better for insulated gear and multi-layer jackets and great for spot treatments. If only the shoulders of your jacket need a touch-up, you only need to spray your shoulders.
How to apply
After washing, spray the entire exterior of your gear. For a jacket make sure you give extra attention to the abrasion areas like the chest, waist, armpits, and don’t forget the hood. Hang your garment to dry
Wash in is great if you need a full DWR treatment. Unlike spray-on DWR you don't have to worry about missing spots. Keep in mind though the DWR is also applied to the inside of your gear. This cold effect the inside fabrics ability to wick moisture and the breathability rating.
How to apply
Check the label on the bottle and put the appropriate amount in your washer and wash. DWR is not a detergent so make sure you wash your garment first.
Waterproof gear is expensive and you don’t want to do more harm than good by washing/drying it improperly, I can not stress this enough, check your manufacturer's recommendations before doing anything.