Best way to re-waterproof a rain jacket?

A reliable rain jacket is an essential piece of gear for anyone who ventures outdoors. However, over time, the Durable Water Repellent (DWR) coating that causes water to bead up and roll off will degrade, leading to a phenomenon known as ‘wetting out’. When your jacket wets out, the fabric absorbs water instead of repelling it, making you feel damp and cold even if the waterproof membrane underneath is still intact. Fortunately, re-waterproofing your rain jacket is a straightforward process that can significantly extend its lifespan and performance.

Understanding DWR and Why it Fails

DWR is a polymeric coating applied to the outermost fabric layer of waterproof-breathable garments. Its job is to reduce the surface tension of the fabric, preventing water from saturating it. While the underlying membrane (like Gore-Tex or eVent) provides the primary waterproof barrier, a functional DWR allows the fabric to breathe effectively by keeping the outer layer dry.

DWR can fail for several reasons: dirt, oil, sweat, abrasion, and repeated washing cycles all contribute to its breakdown. When the DWR is compromised, water will saturate the fabric, making the jacket feel heavy and clammy, and hindering the breathability of the waterproof membrane.

Step 1: Clean Your Jacket Thoroughly

Before you even think about applying a new DWR treatment, it’s crucial to clean your jacket. Dirt, oil, and residues from detergents or fabric softeners can all prevent the new DWR from bonding effectively. Always check your jacket’s care label for specific instructions.

Generally, you should machine wash your rain jacket on a gentle cycle with warm water (not hot). Use a technical cleaner specifically designed for waterproof breathable fabrics (e.g., Nikwax Tech Wash or Grangers Performance Wash). Avoid standard laundry detergents, fabric softeners, and bleach, as these can strip existing DWR and clog the fabric’s pores, impairing breathability.

After washing, rinse the jacket thoroughly to ensure no cleaning agent residue remains. You might even run an extra rinse cycle.

Step 2: Choose Your Re-Waterproofing Method

There are two primary types of DWR treatments available: wash-in and spray-on.

• Wash-in Treatments: These are added to your washing machine cycle after cleaning. They coat all surfaces of the garment, both inside and out. While convenient, some argue they can slightly reduce breathability if the inner fabric also gets treated.
• Spray-on Treatments: These are applied to the exterior of the clean, damp (or sometimes dry) jacket. They offer more targeted application, allowing you to focus on the outer fabric only, thus potentially preserving inner breathability.

The best choice often depends on your jacket’s specific design and your personal preference. For most jackets, especially those with linings that don’t need DWR, spray-on is often recommended. If you have a two-layer jacket where the membrane is bonded directly to the outer fabric, wash-in might be perfectly fine.

Step 3: Apply the DWR Treatment

For Wash-in Treatments:

After washing and rinsing your jacket (while it’s still wet), place it back into the washing machine. Add the recommended amount of wash-in DWR solution according to the product’s instructions. Run a gentle, low-temperature cycle, ensuring the product is thoroughly dispersed. Once complete, remove the jacket.

For Spray-on Treatments:

Hang your clean, damp jacket on a hanger in a well-ventilated area. Spray the DWR treatment evenly over the entire exterior surface of the jacket from about 6-8 inches away. Ensure full coverage, paying extra attention to high-wear areas like shoulders and cuffs. Avoid oversaturation. Wipe off any excess treatment that might pool or drip, especially from zippers or drawcords, with a clean, damp cloth. Some products may recommend applying to a dry jacket, so always check the specific product instructions.

Step 4: Cure the DWR Treatment

Many DWR treatments require heat to activate and bond properly to the fabric. This step is crucial for achieving maximum repellency.

Typically, you can tumble dry your jacket on a low to medium heat setting for about 20-30 minutes. The heat helps the polymers in the DWR bond and cross-link with the fabric fibers. If your jacket’s care label prohibits tumble drying, or if you prefer an alternative, you can also use a warm iron (on a low synthetic setting, protecting the fabric with a towel) or a hairdryer on a low setting. Be very careful not to apply too much heat, as this can damage the waterproof membrane.

Testing Your Re-waterproofed Jacket

Once your jacket has been treated and cured, you can test its renewed repellency. Simply sprinkle some water on the surface. If the DWR is successful, the water should bead up and roll off the fabric, rather than soaking in. If water still soaks in, you may need to repeat the process or ensure you followed all steps correctly, especially the cleaning and curing.

Tips for Maintaining Your Jacket’s DWR

To maximize the longevity of your newly restored DWR and your jacket’s overall performance, follow these maintenance tips:

• Wash Regularly (but not excessively): Clean your jacket when it looks dirty or starts to wet out, using a technical cleaner. Regular cleaning removes oils and dirt that impede DWR.
• Avoid Fabric Softeners: These can leave residues that attract water and compromise DWR.
• Air Dry When Possible: While heat helps activate DWR, excessive tumble drying can cause wear and tear. Air drying on a hanger is often sufficient after the initial heat-curing.
• Store Properly: Hang your jacket in a cool, dry place. Avoid compressing it for long periods, which can damage the fabric and DWR.

By following these steps, you can effectively re-waterproof your rain jacket, ensuring it continues to provide reliable protection and comfort for many adventures to come. A little care goes a long way in preserving your essential outdoor gear.