Painting Objects

Radiators

Radiator finishes must tolerate repeated heating while protecting metal, so coating choice depends on the substrate, existing finish, and actual service temperature.

Painting surfaces

Radiators are commonly cast iron, steel, or aluminum, and coating preparation depends on corrosion, the existing finish, and the unit's service temperature.

Surface	Typical area	Preparation	Main consideration
Cast iron	Traditional column and sectional radiators	Let the unit cool, remove loose rust and failing coating, degrease carefully, and prime exposed iron when the coating system requires it.	Rust, recessed surfaces, service temperature, and coating cure before reheating
Steel	Panel radiators, covers, and steel heating units	Remove grease, rust, and loose paint, then prepare exposed steel with the compatible primer specified by the finish system.	Corrosion, existing coating, heat cycling, and handling during maintenance
Aluminum	Lightweight sectional and designer radiators	Degrease thoroughly and use preparation and primer approved for aluminum and the selected service temperature.	Oxidation, adhesion, factory coating, and thermal cycling

Paint types

Radiator paint should be chosen for the actual service temperature, with enamel, alkyd, or high-heat coatings used only where their specifications fit.

Paint type	Typical use	Main consideration
Enamel paint	Prepared metal radiators when the product approves the operating temperature	Confirm temperature rating, primer compatibility, cure time, and ventilation before returning the radiator to service.
Alkyd paint	Compatible metal radiator systems within the product's temperature limits	Allow the coating to cure fully and verify that repeated heat cycling remains within the coating specification.
High-heat paint	Heating surfaces whose actual service temperature exceeds ordinary coating limits	High-heat paint is not automatically necessary for every radiator; use it when the measured or specified temperature requires it.