If you are working on a wood project that will be used primarily outdoors, such as a gazebo, cedar chairs, cedar garden planters, garden benches or deck, and you want to keep the natural wood finish, you need to waterproof and seal your wood. It can take a relatively short amount of time depending on how much wood you need to seal. It's best to waterproof wood when the project is new, but sealant can also be used on furniture you've had for a while.
Things You'll Need
Orbital palm sander or hand sandpaper
2-quart plastic bucket
Synthetic brush or nylon brush
Wood sealant such as Olympic WaterGuard
Lay your wood pieces out on a shop table, table saw, sawhorses, or outside -- anywhere you can seal them safely and effectively.
Lightly sand your wood to clean up the surface and allow the grain to be exposed. This will soak in the WaterGuard sealer more effectively. You can use an orbital palm sander or hand sandpaper for this.
Wipe away any access dust from the piece with a tack cloth.
Pour about 8 oz. of the Olympic Water Guard (Thompson's WaterSeal is another brand) into your 2-quart bucket. You may need more as you work on your project, but it is always better to work with a small amount at first and use up the solution in your 2-quart bucket completely as you cover your entire project.
Dip your brush into the 2-quart bucket and let the sealant soak into the brush. Use the same technique you would use for painting or staining a piece of wood. Apply liberally to your wood piece to ensure that it is being soaked up into the wood. Brush in the direction of the wood grain.
Seal is the end-grain. This is often forgotten, but it is the most porous part of the wood. If you have a wood chair outside, it will literally suck up water through the end-grain, dry out and crack the whole piece of wood.
Allow the sealant to dry for 24 hours before taking your furniture or project outside.
While makers of these products indicate that only one coat is necessary, consider applying two or three coats on soft or porous woods, such as cedar. If you want the cedar to age over time with that nice silver color, then only apply one coat. I would also apply at least two to three coats on a deck due to heavy use and water collection.