303 Fabric Guard Water & Stain Repellent

Why Marine Fabric Protection Matters

Marine fabrics endure relentless exposure to rain, spray, UV radiation, and airborne contaminants. Over time, even high-quality canvas, Bimini tops, dodgers, and cockpit cushion covers lose their original water repellency. When that protective barrier fades, moisture soaks in, encouraging mildew growth, staining, and premature deterioration. 303® Fabric Guard reverses that decline by depositing a powerful yet invisible coating that causes water to bead and roll off, just as it did when the fabric was new.

How 303® Fabric Guard Works

Applied to clean, dry fabric, 303® Fabric Guard bonds at the fibre level to create a durable barrier against both water-based and oil-based stains. The formula does not form a film or seal the weave shut — breathability is fully maintained, which is critical for marine enclosures and covers that need airflow to prevent condensation and mildew underneath. Once the treated fabric has dried, the product is non-toxic and odourless, so it is comfortable to be around in enclosed cockpit or cabin spaces.

Where to Use It on Your Boat

303® Fabric Guard is versatile enough for virtually any textile surface aboard. It is particularly well suited to the fabrics that take the hardest beating in a marine environment.

• Bimini tops and dodgers
• Sail covers and winch covers
• Cockpit cushion covers and upholstery
• Canvas enclosures and spray hoods
• Dinghy covers and outboard motor covers
• Outdoor seat cushions on flybridge or aft deck

Recommended by Sunbrella®

Sunbrella® is one of the most widely used outdoor and marine fabric brands in the world. The fact that Sunbrella® recommends 303® Fabric Guard for maintaining their fabrics speaks to the product's compatibility and effectiveness. If your boat's canvas or cushion covers are made from Sunbrella® material, this is the treatment the manufacturer itself suggests you use.

Application Tips for Best Results

Getting the most out of 303® Fabric Guard starts with proper preparation. Follow these steps for optimal protection.

• Ensure the fabric is thoroughly clean and completely dry before application
• Apply in a well-ventilated area, away from heat sources, sparks, and open flames
• Spray evenly across the surface, working in sections to ensure full coverage
• Allow the fabric to dry completely before exposing it to water or folding it
• The 473 ml (16 oz) bottle covers approximately 40–75 sq. ft. depending on fabric type and application method
• Reapply periodically throughout the boating season, especially after cleaning the fabric

Safe for Synthetic and Natural Fibres

Whether your boat features acrylic canvas, polyester covers, or natural cotton duck, 303® Fabric Guard is formulated to work across fibre types. It will not change the hand feel, colour, or flammability rating of the treated material, so your fabrics look and feel exactly as they did before treatment — just with significantly improved water and stain resistance.

Specifications

• Available Sizes: 473 ml (16 oz) / 946 ml (32 oz)
• Coverage (16 oz bottle): 40–75 sq. ft. (approximately 3.7–7.0 m²)
• Physical State: Liquid
• Colour: Colourless
• Flash Point: ≥ 122 °F (50 °C)
• Relative Density: 0.85
• Density: 7.8 lb/gal
• Boiling Point: > 150 °C
• Water Solubility: < 0.1 %
• Vapour Pressure: 0.5 mm Hg
• Viscosity (Kinematic): 3 mm²/s at 40 °C
• UN Number (TDG): UN1268
• TDG Hazard Class: 3 (Flammable Liquid)
• Packing Group: III
• SKU — 473 ml (16 oz): #21201
• SKU — 946 ml (32 oz): #14169
• Price — 473 ml (16 oz): CAD $32.95
• Price — 946 ml (32 oz): CAD $49.95

Key Features Summary

• Restores factory-level water repellency — brings aged marine fabrics back to like-new performance
• Repels water-based and oil-based stains — comprehensive protection against the most common marine contaminants
• Preserves fabric feel and breathability — no stiffness, no film, and no change to the original hand of the material
• Does not alter fabric colour or flammability — treated textiles remain visually and safety-compliant as before
• Non-toxic and odourless when dry — safe for use on cockpit cushions, enclosed canvas, and areas where crew spend time
• Compatible with synthetic and natural fibres — one product for acrylic, polyester, cotton, and blended marine fabrics
• Recommended by Sunbrella® — endorsed by a leading marine and outdoor fabric manufacturer
• Easy spray-on application — no special tools or professional equipment required
• Ideal pre-winter treatment — protects fabrics during off-season storage against moisture and condensation
• Available in two sizes — choose the 473 ml bottle for spot treatments or the 946 ml bottle for full-boat coverage