Type of paint depends on type of heating unit

Q I would like to refinish my metal baseboard heating units. What kind of paint should I use?

A If you are referring to baseboard radiator systems for boilers, they don't get very hot and, after a coat of metal primer, can take any kind of paint. Experts, however, advise using an oil-based alkyd paint.

If you are referring to heating units that are individually controlled and often hard-wired into the wall, that's a different matter. You will need to use a special heat-resistant paint and specific techniques. Leon Freshette, author of asktooltalk.com, offers the following suggestions.

Disconnect the unit: Turn off the breakers or remove the fuses that power each unit. Locate the front side panels that conceal the power source and remove both panels to expose the wiring. Disconnect the ground, white and black wires and take care that the black and white wires don't touch. Use a voltage tester to check that the black and white wires are not hot.

Remove the front faceplate to expose and remove the screws (hopefully, not nails) that hold the unit to the wall. Once the unit is free, return to the power source and look for a metal or plastic connector that connects the power source through the back of the unit. If it's metal, loosen the screws or remove the lock nut inside the unit. If it's plastic, remove the plastic wedge that was forced down into the connector and up against the wire. In either case, when you're done, remove the power source from the unit and attach wire nuts to the exposed white and black wires.

Prepare to paint: Lay the heater across a pair of sawhorses and remove the end caps, if they are removable. Clean all the metal pieces to be painted with an all-purpose cleaner and make sure they are thoroughly dried. Working outside on a sunny, nonwindy day would be ideal. Sand any scratched areas using a rubber hand-held sanding block with 320 grit sanding paper. Blend any ragged edges into the surface.

Prime and paint: Apply an aerosol automobile primer to the heater. In damaged areas, you may have to apply a few coats, sanding between coats, to achieve a flat surface. To make painting easier, place smaller pieces on an upside-down cardboard box or try hanging them on a clothesline using a thin wire, such as baling wire.

Reassemble: After the unit has dried according to the paint manufacturer's specifications, reassemble the heater in the reverse order of how you took it apart.

A word of caution before reassembling: It is important to check the power source with a voltage tester again before you handle the wires, in case someone turned the breaker back on or reinstalled the fuses while you were painting the heaters.