How to Waterproof Fabric for Outdoor Use

Outdoor gear and apparel are often made from water-resistant fabrics. But even the most high-tech materials can eventually become saturated and leak over time and repeated use. Applying a waterproofing treatment can restore lost water repellency and keep you dry in wet conditions. This guide will teach you how to effectively waterproof different types of fabric to prepare your equipment for outdoor activities.

What Makes Fabric Waterproof?

Fabric can be engineered to repel water in several ways:

  • Surface coating – A chemical coating is applied to the exterior of the fabric fibers to make them non-absorbent. Polyurethane (PU) and polytetrafluoroethylene (PTFE) are common coatings.
  • Membrane construction – The fabric is laminated with a waterproof breathable membrane like Gore-Tex. The membrane blocks external moisture while allowing internal perspiration to escape.
  • Fiber density – Tightly woven fabrics with dense fibers prevent water droplets from penetrating through the gaps.
  • Hydrophilic treatments – Special chemical treatments are added to the fibers to give the molecules water-repelling properties. DWR (durable water repellent) is an example.
  • Wax coating – Applying wax fills the pores of the material to create a water barrier. Wax is commonly used to treat canvas and leather.

Determining if Fabric Needs Waterproofing

Over time, outdoor gear loses its ability to effectively shed water. To evaluate if your equipment needs re-waterproofing, perform these quick tests:

  • Sprinkle droplets of water onto the surface. If they are easily absorbed instead of beading up and rolling off, the DWR treatment has worn off.
  • Look for darkening or color changes on the material, indicating the fabric is retaining moisture.
  • In a light mist or shower, does water soak through and make the inside damp? Time to reapply waterproofing.
  • After heavy use and washing, does the fabric seem less dense or tightly woven? This can create gaps for water to intrude.

Re-treating the fabric will seal pores and restore water resistance.

What You’ll Need

Waterproofing products and equipment:

  • Water repellent spray for outerwear (Nikwax TX Direct)
  • Tent seam sealer (Gear Aid Seam Grip FC)
  • Wash-in waterproofing (Nikwax Tech Wash)
  • Fabric wax (Otter Wax)
  • Durable water repellent (DWR) spray
  • Sponge or paint brush
  • Masking tape
  • Garbage bags
  • Clothes drying rack
  • Workspace with ventilation

How to Waterproof Different Materials

The exact process will vary depending on the type of fabric. Here are tips for properly treating common outdoor gear materials:

Nylon and Polyester

Nylon and polyester are used to make tents, rain jackets, pants, packs, and sleeping bag shells. The fibers are naturally hydrophobic, so they resist absorbing water. But they rely on chemical DWR coatings to repel water from the surface. Here’s how to reapply DWR:

  1. Set up your workspace in a ventilated area like a garage or outside. The fumes from waterproofing sprays are strong.
  2. Remove any dirt by washing the item according to manufacturer instructions. Skip the fabric softener – it leaves behind a coating that will compromise the DWR treatment.
  3. Lay the garment or tent fly flat and use masking tape to cover any zippers or velcro that could catch overspray. Shake the DWR spray can vigorously and apply a light, even coating from about 8 inches away. Mist across the entire surface, moving methodically to avoid missed spots. Apply two coats, allowing the first to dry before adding the second.
  4. Turn the item over and repeat the spraying process on the other side. Make sure seams, pocket flaps, and hoods are thoroughly coated.
  5. Let the DWR application dry completely, about 24 hours. Then re-wash the item with a technical cleaner like Nikwax Tech Wash to remove any residue and revitalize the breathability and wicking properties.
  6. Tumble dry on low heat or air dry out of direct sunlight to activate and cure the DWR. The treated fabric will now bead droplets.

For waterproof-breathable rain jackets and pants, follow steps 1-4. Then apply a specialty wash-in waterproofing like Nikwax TX Direct instead of standard DWR. This will safely reproof the membrane without compromising breathability.

Cotton and Canvas

Heavyweight cotton canvas is commonly used for tents, tarps and outdoor packs. The loose weave absorbs water readily, so waxing helps create a water barrier:

  1. Set up your workspace in a well-ventilated area. Wax fumes are strong. Cover any nearby surfaces to catch drips.
  2. Wash and fully dry the cotton item first to remove dirt and oils.
  3. Choose a wax formula suited for canvas, like Otter Wax. Heat the wax in indirect sunlight or a makeshift double boiler to melt it into a liquid state for easier spreading.
  4. Use a sponge brush or lint-free cloth to apply a thick, even coating of molten wax across every inch of the fabric’s exterior surface and seams. Work in small sections for full coverage. Let the wax cool and solidify between applications.
  5. Flip over the item and repeat the wax application process on the other side. Pay extra attention to seams and edges.
  6. Allow the wax to cure for at least 24 hours before using the newly waterproofed item. Over time and use, reapply wax to maintain protection. Spot treat wear areas as needed.

For waxed cotton jackets, follow the same steps but use an iron to re-melt the existing wax coating instead of applying new wax, which can compromise the jacket’s breathability.

Leather Boots

Leather boots are naturally water-resistant. But after heavy use, the pores can open up and allow moisture to seep through. Waxing helps close gaps in the material:

  1. Remove laces and clean boots with saddle soap and water to get rid of built-up dirt and oils. Rinse and let dry completely.
  2. Apply a leather conditioner like mink oil while the boots are still dry. This nourishes the leather and prepares it for wax by allowing pores to better absorb the wax.
  3. Select a wax like Otter Wax Leather Salve designed for leather and rub a thick layer into the boots’ exterior with a sponge or cloth. Apply extra wax along seams and stitching.
  4. Let the wax fully saturate the leather for at least 30 minutes. Then polish with a horsehair brush to remove excess wax and evenly distribute the water-repellent coating.
  5. Stuff boots with newspaper or shoe trees to hold their shape as the wax cures overnight. The boots are now ready for protecting feet in wet conditions.

Down Insulation

The fine fibers in down feather insulation lose their loft and warming ability when exposed to moisture. But down is delicate and requires special re-waterproofing:

  1. Never wash down in a washing machine – this can destroy the fibers. Hand wash in a bathtub using mild soap and lukewarm water instead.
  2. Avoid vigorously scrubbing. Gently move the down through the water to release dirt. Rinse several times.
  3. Press water out without wringing or twisting. Lay flat on a clean towel. Roll up and step on the towel to compress more water out of the down.
  4. At this point, the down can be moved to the dryer. Add a couple clean tennis balls. Tumble dry on low, checking frequently. This helps break up clumps as the down dries. Remove before the down is completely dry.
  5. Once dry, use a down-specific waterproofing spray like Nikwax Down Proof. Lightly mist the down, gently moving and lifting sections to reach all the feathers. Do not oversaturate.
  6. Let the treated down fully air dry before returning it to the jacket or sleeping bag. The waterproofing will revitalize insulation and prevent future moisture damage.

Waterproofing Tapes, Sealants and Sprays

In addition to fabric treatments, specialized products can seal leaks and problem spots:

  • Tent seam sealer – Seal tent floor seams and any tiny needle holes by applying a silicone-based sealer along the stitches. Allow to cure before packing the tent away or getting it wet.
  • Waterproofing spray – Use for boots, gloves, hats and items that can’t be washed. Spray a light application and let fully dry. Provides protection without changing textures.
  • Seam grip tape – Sticks to tent flys and tarps to quickly patch small holes or worn spots prone to leaking. Apply to clean, dry areas and press firmly.
  • Duct tape – A classic temporary fix for rips, cracks or holes in fabrics, tarps, tents and boots while on the trail. Replace with a proper fix when possible.

With the right products and techniques, you can keep your outdoor gear performing and protecting you from the elements for many seasons and adventures ahead. Regular maintenance and re-waterproofing is easy with the steps provided above. Just be sure to work in a well-ventilated area, follow all label instructions and properly prep surfaces first for best results.

Frequently Asked Questions About Waterproofing Fabric

Waterproofing outdoor gear and apparel allows them to withstand wet conditions. But you may still have some questions about how to do it properly and effectively. Here are answers to some frequently asked questions:

Should I wash first, or apply waterproofing first?

It’s always best to start with clean fabrics whenever possible. Wash the item first according to care instructions to remove dirt, oils and built-up residues. Then apply the appropriate waterproofing treatment.

How long does waterproofing last?

Most factory DWR treatments can last anywhere from a few weeks of heavy use up to a full season with occasional use. Reapplying waterproofing approximately every 1-2 years will maintain performance. Wax finishes can last longer – up to several years before needing to be reapplied.

Can I put a waterproof jacket or pants in the dryer?

Yes, you can tumble dry waterproof-breathable outerwear on low heat to activate the DWR coating after reapplying. Just avoid very high heat, and skip the dryer sheet – it leaves a residue that can affect breathability.

How do I know if my waterproofing worked?

A simple test is to sprinkle water droplets onto the treated surface. If the fabric is waterproof, the droplets will bead up and roll off without being absorbed. You can also check for leaks in a light rain shower.

Is there a spray-on waterproofing for leather boots?

Yes, there are silicone and wax-based sprays made specifically for leather boots. Apply multiple light coats, allowing drying time between applications. Always test on a small hidden area first before treating the entire boot.

Can I waterproof a down jacket at home?

It’s best to use a dedicated down-proofing spray made for delicate insulation. Never put down in a washing machine – always hand wash gently in a sink or tub, press water out, then air dry before applying waterproofing.

How can I repair small holes or leaks in a tent?

Use a thin seam sealer or waterproof tape made specifically for tent fabrics. Seal along seams for prevention too. Duct tape can work temporarily for emergency fixes while on the trail.

Will re-waxing compromise breathability of a waxed cotton jacket?

Repeated wax applications can eventually reduce breathability over time. For jackets, try just ironing the existing wax to re-spread it without adding more wax buildup. Spot treat heavy wear areas only.

Conclusion

Waterproofing outdoor apparel and gear helps ensure you stay dry and comfortable while enjoying activities like hiking, camping, hunting, fishing and more. Make waterproofing a standard part of your maintenance routine. Reapply treatments periodically as they wear off from repeated use and washing. Invest in quality waterproofing products designed specifically for your gear’s fabric and construction. With some simple cleaning, prep, and a few coats of spray, wax or sealant, you can protect your clothing and equipment from the elements for many seasons ahead. Happy waterproofing and enjoy the outdoors!


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