Painting a Radiator not Always as Trouble-Free as it Should Be

By: Scott Gibson , Contributing Writer
In: Home Improvement Tips

Drying paint smells for weeks, driving homeowners to distraction…

“I am trying to find out whether we have an abnormal situation with our repainted radiators. We had them sandblasted and painted. The painters said they used high temperature paint and warned us they would off-gas for a couple of days. Now that the heat is turned on in our building, our radiators have been off-gassing for more than two weeks. Any advice?”

This polite note hardly covers the frustration this family experienced. Their professionally sandblasted and repainted radiators produced such noxious odors they were afraid to turn on the heat, not for a few days but for weeks. The couple feared the health of their children and elderly house pets might be jeopardized.

A neighbor came up with the idea of hooking the radiators up outside temporarily to allow the paint fumes to cook off there. In the end, the family wondered whether they would have been better off just allowing the old paint to continue peeling.

Where did the job go wrong?

Possibly the paint, says Lawrence Wamanga, who owns a Massachusetts-based company that refinishes and refurbishes cast iron radiators.

If you’re doing the job at home, use a high-temperature primer and topcoat. They should off-gas for the first few hours, possibly a day, as the paint cures. After that, you shouldn’t detect an odor.

Paint must be able to withstand temperatures of up to 250 degrees in a steam system, 180 degrees in a hot-water heating system. Spray-on paint labeled for “high temperature” use is the right product, Wamanga says.

In this case, maybe the paint shop picked the wrong product.

Paula DePasquale, a spokeswoman for Krylon paints, steered us toward a Krylon product called High Heat and Radiator Paint, which is made specifically for this application. Other manufacturers make similar paints.

It’s the right stuff, but DePasquale says it’s still not completely odor-free. All paints take some time to cure and the evaporating solvents will smell. Some can take a week to dry completely.

Instead of paint, Wamanga prefers powder-coating newly stripped radiators. An electrically charged powder is applied to the radiator with a special gun, then the radiator is cured in a 400-degree oven. The result is a much more durable, scratch-resistant surface. And no odor.

Powder-coating takes special equipment and expertise, and it’s obviously more expensive than picking up a few cans of aerosol paint. But where high durability and the absence of paint fumes are priorities, it’s an option to consider.