Sand the White Cedar by hand using 60-grit sandpaper to remove really rough patches. You don’t need to use 60-grit sandpaper on the entire piece of wood, so sanding by hand provides greater control over the sanding process as you target the particularly rough areas.
Sand the entire length of the White Cedar item or raw lumber with 100-grit sandpaper. The 100-grit sandpaper will help buff the wood for a smooth surface that is ready to accept sealant. Since you won’t need as much precision with the finer 100-grit paper, you can use an electric sander to speed up the process.
Wash the wood using a sponge. Ideally, you should just use plain water to remove sanding dust and small particles of debris. In the case of stuck on dirt or grime, you can spot clean with a little bit of dish soap. Just keep in mind that even gentle soaps can leave some residue, so it’s best to just stick to plain water whenever possible. Rinsing the board repeatedly with clean water will help remove most of the soap residue.
Wait at least 24 hours for the wood to dry.
Apply a layer of sealant to the White Cedar using a foam brush. Any type of general water-repellent wood sealant or wooden deck sealant will work on this type of wood. Apply the sealant only to pure, natural White Cedar; while staining can add rich color to the wood, it diminishes the protective properties of the sealant. Sealants applied to natural cedar will help encourage the natural aging of the wood, enhancing the natural protection of the wood.
Wait at least 48 hours for the sealant to fully dry before using the pre-constructed cedar item or building with your sealed White Cedar lumber. Consult the container of your specific wood or deck sealant to see how long the sealant will last; in most cases, you’ll need to reapply sealant every two years.