For over 150 years, radiators have kept houses warm. While yours is unlikely to be so old, it may show indications of wear, such as rust, chipping, or an original hue that doesn’t match your decor.
Paint, fortunately, can turn back the clock on any working or non-operational, hot-water or steam cast-iron radiator; it can even spruce up a unit composed of mild steel, which is steel with a trace of carbon. (On the other hand, naturally rust- and fade-resistant stainless steel or aluminum radiators aren’t commonly painted; those metals are less likely to require restoration in the first place, and these radiators have a more rigid, less pliant surface that isn’t particularly receptive to sanding/painting.)
Consider what color best matches your vintage radiator—a classic metallic or something more eye-catching—then continue reading for comprehensive instructions on how to paint a radiator. In only a weekend, you can transform an outdated appliance from an eyesore to the main point. And don’t put it off: You’ll want to spruce up this metal fixture whenever you can turn it off long enough to paint it.
STEP 1: Select the best priming and paint for a metal radiator.
Use spray paint cans to prepare and paint a radiator for the finest coverage around the curves of this fixture. Select an oil-based aerosol primer and either an oil- or water-based interior paint approved for use on metal surfaces. Look for the following characteristics in your radiator:
If you wish to paint a non-functional radiator, both the primer and paint you apply should be rust-resistant.
If you want to paint a radiator that will heat your home as the weather cools, the primer and paint should be rust-resistant as well as able to handle the high temperatures that radiators create.
Color choices will be determined by the variety available in that specific sort of paint as well as the desired effect. To help your radiator blend in, use a color that closely matches the color of the wall behind it; to make the radiator stand out, choose a color that contrasts with the backdrop wall.
STEP 2: Get the radiator ready.
Turn the control valve (found at the unit’s base) clockwise until it reaches the “off” or closed position and let the device cool entirely. Then, using masking tape, cover the control valve as well as the air bleeder valve (placed near the top of hot-water radiators) or the steam vent valve (located near the top of two-pipe steam radiators) or the air vent valve (on the side of one-pipe steam radiators). Avoid painting vents and valves on a functioning unit because the paint might clog them and make them difficult to turn.
STEP 3: Set up your workspace.
Apply masking tape to the wall around the radiator’s perimeter and drop cloths to the floor beneath the unit to protect the surrounding surfaces from overspray. While painting, open a window to increase airflow and wear gloves and a respirator.
STEP 4: Sand the radiator’s metal surface.
Scrape a tiny, inconspicuous part of the radiator surface with a screwdriver blade and examine for flaking to see whether it has been painted or varnished previously. If there is no flaking, use coarse-grit sandpaper to smooth off any pitting caused by heavy rust (e.g., 40- to 60-grit). Then, using fine-grit sandpaper (e.g., 80- to 120-grit), sand all surfaces to eliminate mild rust accumulations and obtain a smooth, paintable surface.
If you’re covering a previously painted radiator, first test the old paint for lead using a lead paint test kit (available at home centers for $7 to $15). Lead is more likely to be found in paint on radiators in homes constructed before 1978. Caution: Never scrape, sand, or otherwise disrupt the surface of a lead-painted radiator because you risk releasing lead particles, which can harm the central nervous and endocrine systems if breathed or eaten and can even be lethal at high levels of exposure. Wait for the results before sanding or stripping away any cracked paint using one of the following methods:
- If the test is negative, scrape away cracked/chipping paint from any of the radiator surfaces using a putty knife. Then, using the sanding process described above, sand the surface.
- If the test results are good, have a professional refinisher remove the paint, or use an ecologically friendly paint remover like Citristrip. These products trap lead in gel, preventing lead particles from becoming airborne.
STEP 5: Remove the dust.
To eliminate sanding dust, run a tack cloth over the radiator surface. Then, using a moist cloth, wipe down the surface to eliminate any remaining dirt and debris. Allow the radiator to dry completely.
STEP 6: Apply a coat of primer to the radiator.
Spray an equal coat of primer over all visible surfaces using a back-and-forth motion while holding the proper metal spray primer upright and 10 to 16 inches away from the radiator. Allow the priming application to cure completely before painting (Rust-Oleum High-Performance System Enamel Aerosol primer, available on Amazon, dries in 24 hours).
STEP 7: Apply paint to the radiator.
Using the same approach as for the primer, apply an equal layer of high-temperature metal spray paint in a back-and-forth motion to all visible surfaces of the radiator.
STEP 8: Organize your workstation.
Discard the drop cloths and painter’s tape from the wall and radiator valves. Turn the radiator control valve counterclockwise to the “on” or completely open position if the radiator is working.