Things You'll Need
Electric belt sander with coarse-grit sanding belt
Electric orbital sander with fine-grit sanding wheel
2 saw horses
Eye protection goggles
Press board, commonly called Particle Board, is a highly porous panel of lumber which consists of pressure-compacted wood dust and particles. This lumber is used in inexpensive build-on-location furniture and is generally covered with a vinyl or Mylar finish. However, it is sometimes painted with low-moisture spray paint. Since the wood is porous, it is highly absorbent and it will warp when using liquid paint removers and thick high-moisture paints. Removing paint from this form of lumber requires you to use a slightly higher level of manual labor.
Put on a dust mask, gloves and eye protection goggles. Lay the painted board onto the saw horses, placing the saw horses 1 foot from each end of the board.
Run your extension cord to a standard wall outlet. Plug the belt sander into the extension cord and turn it on to a medium speed setting.
Set the sander down onto the painted surface in the center of the board. Using very light downward pressure, move the belt sander in a slow forward and backward movement until you begin to see a bare wood surface.
Move the sander outward from the newly uncovered wood and continue sanding the paint from the board outward toward it's edges.
Turn off and unplug your belt sander and set it off to the side. Plug your orbital sander into the extension cord and turn it on to its highest setting. Lightly sand the entire surface of the board, using a circular movement pattern, until smooth, and finish by wiping off all dust particles with a dusting cloth.
If you will be repainting your board, use a paint sprayer or spray paint cans to spray very fine layers of paint at a time onto the wood surface and allow each to dry thoroughly. Applying heavy wet paint to press board will cause moisture absorption into the porous wood which may cause your wood to warp and curve.
Belt sanders can sand deep depressions into your wood surface if held in one place too long. Always keep your belt sander moving, barely using any downward pressure at all.