Raised Areas

• 1). Dry the wet spot by using a hair dryer. Using a heat gun may create temperatures that could ignite the particleboard. If you have time, you can let the particleboard dry naturally.
  
  
• 2). Sand the water-damaged area with a medium-grit sandpaper by hand or by using an electric sander until the spot is flush with the dry areas. Finish sanding with a finer grit.
  
  
• 3). Vacuum or sweep up the sawdust created when sanding down the damaged particleboard. If the surface is likely to get wet again, apply a waterproofing material and allow it to dry.
  
  

Disintegrated Particleboard

• 1). Dig out the particleboard's soft spots with a sharp object like a screwdriver or knife if the particleboard has loosened and is powdery. Once the spot has thoroughly dried, vacuum the residue or sweep it thoroughly.
  
  
• 2). Apply wood filler, following the directions on the can or tube. Use a putty knife to smooth the top of the repair to make sure that the surface is level with the rest of the particleboard.
  
  
• 3). Sand the surface once the wood filler has thoroughly dried. Vacuum the dust away from the surface. Apply sealer if the area is likely to get wet again.