10 Best Waterproof Wood Sealers 2025 in the United States

The Ready Seal 512 is an oil-based exterior stain and sealer designed for wood surfaces, available in a 5-gallon pail of Natural Cedar color. One of its key strengths is the ease of application; it requires no primer, back brushing, or wet-line application, and it self-blends, making it 'goof proof.' This makes it an excellent option for DIY enthusiasts or those who might not have much experience with wood sealers. The ability to apply it using a sprayer, roller, or brush adds to its versatility.

You can also apply it in any temperature range, which is convenient for varying climates and conditions. Another advantage is that it provides UV protection, helping to preserve the color and integrity of the wood over time. It reaches its true color in about 14 days, which is relatively quick, and the flat finish gives a natural look to the wood.

However, its oil-based composition might be a drawback for those who prefer water-based products due to environmental concerns or easier cleanup. It also can't be applied over painted or newly stained surfaces, which could limit its use in some scenarios. Despite these minor drawbacks, it performs well for most users.

The Seal-Once Marine Premium Wood Sealer is a versatile and effective option for waterproofing wood, especially in environments exposed to constant moisture like boat docks, decks, and outdoor furniture. Its water-based, ultra-low VOC formula ensures that it is environmentally friendly and safe for aquatic life, making it a suitable choice for near-water applications. One of its notable strengths is its UV-stable coating, which offers protection against sun damage, and its ability to form a water-resistant shield around wood fibers, preserving the wood's natural color.

This sealer is also designed to penetrate deeply into the wood, creating a flexible and breathable barrier that enhances durability and longevity. Additionally, it combines the functions of a sealer, stain, and finish in one product, simplifying the application process and offering a fast drying time with easy clean-up using soap and water.

However, it should be noted that being a clear sealer, it may not provide the rich color enhancement that tinted sealers offer. Furthermore, while the product dimensions and weight are reasonable for handling, it may not be the most cost-effective option for larger projects due to its per-gallon pricing. This product is best suited for users looking for a reliable, eco-friendly wood sealer for areas exposed to water and sunlight, who also appreciate the convenience of a combined sealer and stain.

Ready Seal 120 Redwood Exterior Stain and Sealer is an oil-based wood sealer designed for outdoor use, providing a flat finish that enhances wood’s natural look with a rich redwood tone. It stands out for its ease of application — you can use a sprayer, roller, or brush, and it doesn’t require primer, back brushing, or thinning. This makes it very beginner-friendly and reduces the chance of streaks or uneven spots. The product is also versatile because it can be applied in any temperature, which helps if you’re working outdoors in varying climates.

The sealer offers good protection against UV rays, mold, and mildew, helping wood last longer outdoors. Its color darkens initially but settles into its true shade over about two weeks, which is helpful to know for planning your project. One gallon covers around 125 square feet, making it suitable for medium-sized projects. On the downside, it’s not meant to be applied over painted or freshly stained surfaces, so prepping is important.

Also, since it’s oil-based, drying time can be a bit longer compared to water-based sealers. The flat finish means it won’t have a shiny look, which some may prefer for a natural appearance but others might find less vibrant. Ready Seal 120 is a dependable choice for someone who wants a straightforward, reliable sealer that works well with minimal fuss, especially for outdoor wood surfaces needing UV and mildew resistance.