MDF takes paint beautifully — but only if you prep it correctly first.
Why Prep Matters with MDF
MDF has a smooth face but a porous edge. If you apply paint directly to a cut edge without sealing it first, the edge will absorb the paint unevenly and raise slightly, giving a rough, blotchy finish. The good news: it's easy to avoid with the right approach.
Step 1 — Fill Fixings and Gaps
Once your skirting is fixed to the wall, fill nail holes and any gaps at the top edge (where skirting meets plaster) and bottom edge (where it meets the floor) with a flexible decorator's caulk. Use a fine filler for nail holes. Allow to dry fully.
Step 2 — Sand Lightly
Sand the filled areas back flush with 120-grit paper, then finish with 180-grit over the whole board face for a smooth, even surface. Wipe down with a damp cloth to remove dust.
Step 3 — Seal Cut Edges
If you've cut any boards on site, seal the cut ends and edges with a thin coat of PVA diluted 50/50 with water, or a dedicated MDF primer. Allow to dry before painting. Our primed boards already have the face sealed — you only need to address fresh cuts.
Step 4 — Apply Undercoat
Apply one coat of a good quality water-based undercoat. Work with the profile, getting paint into all the curves. Allow to dry for the manufacturer's recommended time, then sand lightly with 240-grit. Wipe clean.
Step 5 — Apply Topcoats
Apply two coats of your chosen topcoat — eggshell or satin finishes work best on skirting. Avoid full gloss on MDF as it tends to highlight any surface imperfections. Sand very lightly between coats with 320-grit for a glass-smooth result.
Tips
- Always use water-based paints on MDF where possible — solvent-based products can cause the surface to swell slightly.
- Keep a wet edge — don't let paint dry mid-stroke.
- Our primed boards give you a head start — the face is already sealed and ready for undercoat.