A small amount of water damage, such as spots on your cupboard doors, does not mean that your cabinets are permanently damaged. As long as the spots are limited to the surface and the wood is not warped, cracked or rotting, you can repair and refinish the cabinets to make them look like new.
If the water spots are not any deeper than the finish, you can buff them away with fine steel wool; you do not need to strip or refinish the cabinets unless you want to change their appearance. Use 0000 steel wool dipped in tung oil and work in a gentle circular motion until the water spots disappear. Apply tung oil to the entire surface using a clean lint-free rag or a paintbrush. Let the oil finish dry overnight and apply a second coat.
Strip It All
If the water damage has gone beyond the finish and reached the wood, or you want to change the look of your cabinets by repainting or restaining, you will need to strip the existing finish. There are two ways to accomplish this: Use a chemical stripper and wipe the old finish away, or sand down to the wood with medium-grit sandpaper. Once the finish is removed, make any necessary repairs, such as sanding away any remaining water marks with fine sandpaper and filling in any holes, cracks or chips with wood putty.
Paint or Stain
Apply a thin coat of paint or stain using a high-quality brush with natural bristles. If you are using paint, choose a semi- or high-gloss finish that is easy to clean and resists water damage. Apply at least two coats. If you are using stain, apply as many coats as necessary to achieve the desired color. Let the paint or stain dry completely, usually at least four to six hours, before applying a clear finish.
You don't have to apply a clear finish over semi- or high-gloss paint, but it will offer extra protection. A finishing coat is necessary if you used stain. Apply a thin coat of clear polyurethane with a natural-bristle brush. Let it dry and buff lightly with fine steel wool. Wipe away any dust and apply a second coat of clear polyurethane.