How to Paint MDF

To paint MDF, seal the cut edges first, prime everything with a shellac-based or oil-based primer, sand lightly, then apply two thin coats of a hard enamel. The faces of MDF are smooth and paint beautifully; the edges are porous and soak up paint, and water-based products applied straight to raw MDF raise its fibres. Get those two things right and MDF gives the smoothest painted finish of any board.

What you need

• 180 and 220–320 grit sandpaper and a sanding block
• Diluted PVA glue, drywall joint compound or a filler primer for the edges
• Shellac-based or oil-based primer
• A cabinet or furniture enamel
• A fine foam roller and a good brush, or a sprayer

Step by step

1. Sand the faces lightly with 220 grit to remove the factory glaze, and round over sharp edges slightly so paint does not thin on them.
2. Seal the edges. Brush on PVA glue diluted about 1:1 with water, or skim them with joint compound. Let it dry and sand smooth with 180 grit. Repeat until the edges feel as smooth as the faces.
3. Prime everything with a shellac-based or oil-based primer. It seals the fibres so later coats stay smooth.
4. Sand the primer lightly with 320 grit and wipe off the dust.
5. Paint two thin coats of enamel, sanding lightly between them. Thin coats level better and dry harder than one thick coat.
6. Let it cure for several days before heavy use, even when it feels dry.

Tips for a smooth finish

• Work in light that rakes across the surface to see ridges and dust.
• Spray for the best result on doors and cabinets; a foam roller is the next best thing.
• Paint the backs of doors and panels too, so they stay flat.
• Use moisture-resistant MDF in kitchens and bathrooms, and seal every edge, including the hidden ones.

Projects to paint

MDF is the classic board for painted shaker doors, built-ins and bookcases. Our plans give the parts in MDF or any other board: