Hardboard, also referred to as chipboard, is a material made from wood chips pressed together and bound with synthetic resin. It is a cheap building material used in construction for home exteriors, flooring, furniture and cabinetry. Hardboard is also commonly covered with gesso or canvas and used by acrylic and oil painters as a painting surface. Before painting, hardboard must be prepped and primed if changing the color of the hardboard. If it's a new piece of hardboard, you can go straight to painting.
Lift and remove any loose or peeling paint gently, using a paint scraper. Gently press the paint scraper into the wood and move downward to scrape paint. Do not dig or gouge into the hardboard.
Combine three parts warm water to one part household bleach in a bucket. Use a sponge to rub on any mildew on the hardboard. Let the mixture work into the hardboard for 20 minutes. Add more solution as needed to remove mildew, if necessary. Use a cloth dampened in cool water to wash away the bleach solution once all mildew is removed.
Mix 1 teaspoon liquid dish soap per every cup of warm water in a bucket. Dip a sponge in the mixture and clean the hardboard. Remove any dirt, dust and debris from the wood. Use a cloth dampened in cool water to remove soap residue.
Pour latex primer into a paint tray. Depending on the size of the item you are painting, dip a paintbrush or paint roller into the paint. Roll or paint over the textured portion of a paint tray to remove excess primer.
Prime the hardboard. Beginning at the top of the hardboard, slowly paint downward in a long, even stroke. Continue until the hardboard is covered in a layer of primer. Allow the hardboard to dry.
Add a second layer of primer, if needed.
Pry open the paint can with a butter knife. Use a paint mixing stick to stir the paint thoroughly. Pour the paint into a paint tray.
Dip a paintbrush or roller into the paint, depending on the size of the object to be painted. Roll or paint over the textured portion of a paint tray to remove excess primer.
Paint the hardboard. Beginning at the top of the hardboard, slowly paint downward in a long, even stroke. Continue until the hardboard is covered in a layer of paint. Allow the paint to dry.
Add two to three coats of paint depending on desired color.