The methods for sealing a wood countertop differ depending on what the countertop is used for. Kitchen countertops are often used for food preparation tasks, such as kneading bread dough or cutting meat, and therefore must be food-safe. The countertop of a work bench or some other piece of furniture, however, probably won't come into direct contact with food on a regular basis, and can be sealed using a longer-lasting method.
List of Items Needed
- Hand power sander with 120- and 240-grit sandpaper
- Oscillating tool with wood sandpaper accessories
- Drying oil or wax finish (food-safe only)
- Polyurethane or similar sealant (other countertops only)
- Paint brush
- Safety goggles
- Respirator mask
Sand the wood countertop to prepare it for sealing, using a hand power sander for large, open spaces and an oscillating tool with wood sandpaper accessories for the edges and corners. Employ 120-grit sandpaper for one round of sanding, and then 240-grit for a second round. Always sand with the grain.
Apply a drying oil or wax to a food-safe countertop with a paintbrush, using long, even strokes. Wait overnight and apply a second coat, then repeat. At least three coats of this type of sealant are necessary to adequately seal the wood. If your countertop does not need to be food-safe, skip this step and go on to Step 3.
Use a clear sealant, such as polyurethane, on a wood surface that does not need to be food-safe. Apply the sealant with a paintbrush, using long, even strokes. Wait as directed by the instructions (usually several hours) and apply a second coat.
Tips and Warnings
- To use a wax, such as beeswax or paraffin wax, you must first melt it in a double-boiler.
- If you are re-sealing the countertop, first remove any caulk that might be sealing the edges of the countertop, such as where the countertop meets the backsplash.
- When re-sealing a heavily used kitchen countertop, you may find it necessary to remove knife marks from the wood. In this case, add a preliminary sanding stage using coarse sandpaper, such as 60 grit.
- Always wear safety goggles and a respirator mask when working with power sanders.