Medium-density fiberboard (MDF), an engineered wood product, works beautifully for decorative trim as well as cabinetry, shelving and furniture because it doesn't expand or contract when properly finished, unlike real wood. Constructed of ground wood and glue, the smooth, even texture of MDF makes paint the ideal finish choice. For most applications, satin and semi-gloss paints are best, standing up well to gentle cleaning, while high-gloss products add an eye-catching shine to baseboards and crown molding.
Things You'll Need
- Drywall compound
- Safety glasses
- Face mask
- 120- to 150-grit sandpaper
- Tack cloth
- Oil-based primer
- Interior paint
Seal the rough, porous edges of the MDF with drywall compound, spreading the compound evenly with a gloved finger. If left unsealed, the edges of MDF absorb moisture, causing the material to warp and crack. Allow the compound to dry completely.
Sand the MDF lightly with fine-grit sandpaper to remove dirt and provide better adhesion for the primer. Sand the compound-sealed edges as well, smoothing it out until you cannot tell the difference between the smooth surface of the MDF and the formerly-rough edges.
Wipe the MDF down with a tack cloth to remove sawdust and dirt.
Apply oil-based primer evenly with a paintbrush. Avoid water-based primer. MDF fibers absorb the moisture, causing the grain of the MDF to rise. Allow the primer to dry according to manufacturer directions.
Apply a thin coat of latex or oil-based paint. The sealing effect of the drywall compound and oil-based primer prevents the MDF from absorbing the water in latex paint. Let the paint dry and then apply a second coat for a smooth, opaque finish.