Paint radiators with a spray gun

It is not uncommon for the paintwork of old radiators to yellow over the years and become increasingly unsightly. There are various reasons for using a special spray gun instead of a brush or paint roller when applying a new layer of paint. Here, too, there are a few things to consider for a good result.

Nothing works without the right preparation

While modern radiators are usually powder-coated on the surfaces, the paint on older radiators can puff up or peel off unsightly over the years. In such a case, a trained eye should first assess whether there is a strong rust perforation. If some areas are actually already heavily rusted through, a new paint job would in a sense only whitewash this problem. The consequence can at some point be water damage from a leaky radiator.

If everything is still in order with the basic substance of the radiator, the old layer of paint must first be removed. A drill (€ 48.00 at Amazon *) with a special grinding attachment can be used for this. You can also sand the radiator by hand. We recommend using 200 grit sandpaper.

Note that valves, screw connections and similar parts should be masked with painter's tape before applying the paint. In many cases the thermostat can be unscrewed. However, this then also leads to the heating of the radiator. Therefore, ideally, you should paint the radiator outside of the heating season. However, you can also use adhesive tape stuck crosswise as a blind plug to press in the pin of the stuffing box. This stops the flow of water and keeps the radiator cold.

The selection of suitable equipment and paints

Compared to applying paint with a brush or roller, spray application offers various advantages:

  • absolutely even color distribution
  • no traces of brush hair
  • the varnish can be applied thinner
  • the job can be done much faster
  • hard-to-reach areas can be painted more easily

The thinner application of paint is a very important argument, as too thick a layer of paint can reduce the efficiency of the central heating. You don't necessarily have to buy an expensive airbrush system with a compressor and airbrush gun to repaint your radiators. There are now spray guns especially for do-it-yourselfers that can do without an external compressor. In such fine spray systems, the paint is sprayed either by means of a vibrating armature motor or by the air ejected from a turbine (as in a vacuum cleaner).

It may be that you first have to dilute the radiator paints specially made for this purpose for use with the spray gun. But you can also use heat-resistant, water-based acrylic varnishes, which are very easy to dilute with water. These also do not yellow as strongly as synthetic resin paints at higher temperatures.

Important basics for handling the spray gun

Before painting your radiator, you should first test spray it on a piece of paper, cardboard or wood to check that it is working properly and the consistency of the paint. Move the spray gun in even paths with a distance of about 20 to 30 cm from the surface to be treated. Do not stay in one place for too long, otherwise the layer of paint will be too thick at this point.

After work, you should spray the spray gun through with water or a suitable solvent. In this way, you can maintain their functionality by removing paint residues from the fine components. You can of course also use the device to paint other surfaces such as doors.

When working with a spray gun, regardless of the type of paints and varnishes used, you should always ensure that your health is protected with a respirator and suitable protective clothing.