To Paint or Not to Paint - Restoring Your Cast Iron Radiator

Restoring traditional cast iron radiators to their former glory is not too difficult a task, especially when you hire a professional refinisher to remove the old paint. Aluminium oxide and compressed air is used to blast off old paint and debris. Once the dirt and dust have been removed the radiator is sprayed with an even coat of primer ensuring that the areas between the sections are also coated.

The primer can be purchased in a spray can and a steady spray action while keeping the can moving will prevent dripping and create a nice smooth finish. The spray also allows for full coverage between the sections. Once the primer is dry to the touch, spray on an enamel paint topcoat. A better finish is obtained with the spray enamel as using a brush on enamel will clog the detail on the cast iron radiator.

Do-it-yourself enthusiasts should be aware that painting cast iron radiators with latex or oil based paints, such as those that would be applied to plaster or drywalls/ceilings is not recommended. This is firstly due to the fact that these paints are viscous and go on thickly when applied thus obscuring the fine detailing on the radiator. These paints also adhere rather poorly to metal and are not bonding powder coating of metal surfaces that heat up rapidly to high temperatures such as on a radiator.

When latex and especially oil-based paints are heated to high temperatures there is a dramatic increase in off-gassing of VOCs (Volatile Organic Compounds) which in tu pose a health risk and can cause a serious increase in respiratory, eye and skin problems. The composition of these paints makes them unsuitable to be applied to any sort of surface that repeatedly heats up and cools down.

The bottom line is that any kind of general use house paint should not be used on radiators. If your radiators have already been coated in latex or oil-based paint then serious thought should be given to having it safely removed, especially if the paint used is lead-based. Using appropriate and safe paint increases the radiant heat value of the radiator, prevents you and your pets from getting lead-poisoning, and improves the aesthetic appearance of the radiators themselves.