Painting properly a metal surface

Metal pieces can get rusty. This slow oxidation phenomenon touches particularly surfaces exposed outdoors and in contact with air and water, such as doors, fences, stairs, etc. Fortunately, there is a solution to protect these from rust: the use of rustproof paint. Extremely resistant and protective, rust-proof paint has both the advantages of water-based paint and oil paint. And, as most paints on the market, it exists as a paint, shellac, and varnish, and can be used as much on new surfaces as on already rusty surfaces. But before getting into its use, it’s important to know about the specific technique in order to maximize its benefits.


Even though the color selection is thin compared to other products, rustproof paints are offered in matte, satin and glossy finishes. And besides the paint itself, we also need to choose a primer and/or specific coating, depending on the type and condition of the substrate.


brush cleaning rusty wall

First of all, it’s essential to adequately prepare the area. Make sure you have a ventilated space, get gloves, painter’s clothes, brushes, and rollers. For large surfaces, the paint gun (commonly called paint sprayer) is preferred for uniform and smooth results.

Then, we need to prepare the surface to be treated. If the metal is new, we first have to clean with a degreaser it to get rid of dust and dirt accumulations. If the metal is old or has already been painted, we have to brush and scrape it to get rid of peeling paint of previous coats. We recommend doing so with a pressure washer. This tool is expensive, but very efficient, mostly used for large surfaces, and combined with a good grinding.

After that, we are ready to apply either a rust converter or a rust annihilator that impedes the propagation of corrosion. To finish the preparation, we think about applying a primer in order to facilitate the adhesion of a rust-proof paint. Between each step, it’s important to sand the entire surface.

applying paint

Now that your surface is ready, it’s time to apply paint or another coating. The number of coatings to be applied depends on whether it’s water-based or solvent-based. Each coat must be evenly spread and thick enough. We apply them with a spray gun on large surfaces, but with brush and roller for other details. We must make sure to cover the whole surface in all the nooks and crannies. Otherwise, rust could come back.

We generally advise waiting at least 24 hours before applying the second coat. However, in the case of heavy rain or snow, a third coat could be necessary. It’s important to know what product to use for the finish.

Once the last coat has been applied, it’s important to clean all tools with water. The smooth finish of rustproof paint is similar to that of epoxy, meaning it’s almost perfect. Once this is done, you should be good for at least 10 years.

Finally, even if it’s difficult to apply and it asks for some preparation, rust-proof paint ensures the protection and conservation of the nice metal pieces which could get rusty otherwise. If the task seems overwhelming, it’s a good idea to hire a professional painter who knows what he is doing.