Clean, sand, prime and repaint a radiator safely once it's off and fully cool, for a smooth, durable finish.
PR-01Turn off and cool the radiatorTurn the thermostatic valve and lockshield valve to off, or turn off the heating at the boiler. Leave the radiator for at least 2-3 hours until it's completely cool to touch. Painting a hot radiator gives a poor finish and the fumes will be worse.
PR-02Protect the roomLay a dust sheet under and behind the radiator, covering the skirting and floor. Mask the wall behind the radiator, the pipes, and both valves with masking tape so you get a crisp edge. Open a window, as radiator paint has strong fumes.
1 roll · Masking tape (25mm) PR-03Clean the radiator thoroughlyWash the whole radiator with warm water and sugar soap to remove grease and dust, including between the fins with a radiator brush. Rinse with a clean damp cloth and let it dry fully before you touch it again. Any dust left behind will show through the paint.
PR-04Key the surfaceLightly sand the whole radiator with fine abrasive paper to break the shine on the old paint, so the new coat grips. Wipe off all dust with a damp cloth, then go over it with a tack cloth. Don't skip this on old gloss finishes.
1 pack · Fine abrasive paper (240 grit) PR-05Repair and spot-primeFill any chips, dents or rust spots with a fine filler, then sand smooth once dry. Spot-prime any bare metal with a metal primer, especially over filled areas and rust, and let it dry fully before painting. Skip this step if the radiator has no bare metal showing.
1 tube · Fine surface filler 1 250ml tin · Metal primer PR-06Apply the first coatUse a radiator brush or narrow roller to get behind the panels and between the fins, then work over the visible surfaces in thin, even strokes. Start at the top and work down so drips get covered by the next stroke. Don't overload the brush, thin coats look better and dry faster.
1 tin · Radiator paint (500ml) 1 each · Radiator roller or angled brush PR-07Let dry and apply the second coatCheck the tin for drying time before recoating, usually 2-4 hours for touch-dry. Apply a second thin coat the same way as the first, paying attention to the edges and fins where coverage is easy to miss. Two thin coats always look better than one thick one.
PR-08Cure, then turn the radiator back onLeave the paint to cure fully before switching the heating back on, usually 24-48 hours, check the tin for the exact time. Turning the heat on too soon can make the paint tacky or smell strong for longer. Once cured, turn the valves back on and check for any patchy spots.
PR-09Tidy upRemove the masking tape once the paint is fully dry, pulling it away slowly to keep the edge sharp. Clean brushes and rollers according to the paint tin, most radiator paints need white spirit rather than water. Fold up the dust sheet and give the room a final air.
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