Spot swelling is an old woodworkers trick to swell fibers in the wood to repair dents. The technique of spot swelling is used when sanding the surface is not an option, such as when the wood already has a top-coat of lacquer. By surgically adding a few drops of water you can swell the wood inside the dent or depression. After the wood puffs up, you can then sand the swelled fibers flush with the surface.
Things You'll Need
Tape around the area that you want to swell, such as a dent in the wood. Lay short strips of masking tape around the perimeter of the dent.
Dip a cotton swab in water. Touch the tip of the cotton swab to the dent, applying a drop of water to the dent. Wait 15 minutes for the water to absorb into the dent and apply another drop of water.
Apply water a drop at a time, waiting 15 minutes in between applications until the wood will not absorb any more water. Wait 24 hours.
Apply more water every 15 minutes for an hour. Wait 24 hours for the water to dry.
Sand the dent down flush to the surface with sandpaper. Remove the tape.
It may only take a few minutes, or up to 48 hours for the wood to swell up, depending on the species of wood. Apply a drop of clear lacquer to the sanded area, or color the sanded area first with stain marker and then apply some lacquer.
If the wood has a lacquer finish on it, be careful not to drip water on it. Water can cause lacquer to turn white.