DIYers often worry about painting exterior metal incorrectly. However, whether you’re painting galvanised steel or rusted metal, the approach is the same as any other surface: preparation is key.
Our professional decorators at Scott Anson Painters and Decorators Ltd have plenty of experience painting exterior metal. This article will explore the process in further detail.
Prepping the Surface
The best technique for preparing a metal surface depends on the quality of the metal surface to begin with. A different approach is required when painting a rusted surface than if the surface is brand new. Doing it right should mean the paint will stick better and less layers will be required, leaving a much better finish that will last.
Painting Rusted Metal
It’s quite common for DIYers to look at rusted metal and think it’s beyond repair. However, with the right cleaning, priming and painting techniques, it is possible to revitalise and preserve what is left of the metal.
- Step 1: Remove Loose Rust – It’s always better to prepare a corroded surface before painting. First remove any loose rust using a wire brush. Once larger areas of rust have been cleared, we would recommend to test the integrity of the metal surface with a light tap using a tool, or alike.
- Step 2: Sand the Rust – Sand or scrape off any rust to expose the good metal surface. If the surface is too pitted or pin-holed with rust, the metal may be unsalvageable. In these cases, replacing the metal would be the recommended option.
- Step 3: Clean the Surface – All debris needs to be cleaned from the metal surface before painting. First use a brush to remove as much of the dust and flakes as possible, then use a wet cloth and degreaser to remove oil and grease.
- Step 4: Anti-Corrosion Primer – This type of primer has been developed for covering rusted steel surfaces and offers great protection against further corrosion. It has rust-inhibitive properties that will keep exterior metal surfaces in better condition for longer and prevent reddish-brown rust from bleeding through the paint.
- Step 5: Apply the Top Coat – The type of top coat chosen depends on the primer used. Some primers will require an oil-based top coat paint as opposed to a water-based one, so it’s important to check first. Lighter coloured paints will probably need a few coats.
Painting Non-Rusted Metal
If the metal surface isn’t rusted you can start from step three. Although there are paints such as Dulux Metalshield paint that don’t require a primer, it’s still recommended to use one as it can prevent the surface from rejecting the paint.