How to repaint brown aluminium window frames?

Adam123

Hi everyone,

I have an old 70s home with brown aluminium window frames.
Do I need to use an etching spray paint first or just a primer?

Here’s a few pics. On the window on the front of the house the coating has come off on a strip at the front of the house.

Thank you

JacobZ

Hi @Adam123,

The first step is to give the frames a thorough clean to remove any dirt, chalky oxidation, grease and contaminants. A quality sugar soap works well for this. Once clean and dry, lightly sand the entire surface with fine sandpaper, such as 240-grit, to dull the existing finish and provide a key for the new coating. Pay particular attention to any areas where the existing coating is peeling or flaking, feathering the edges so there isn't a noticeable transition between bare aluminium and the remaining coating.

Once you've finished sanding, wipe away all dust and then carefully cover the glass, surrounding walls and any hardware you don't want painted using painter's tape and masking film. Taking the time to mask everything properly will make the spraying process much easier and produce a neater result.

For the areas where the coating has come off and bare aluminium is exposed, I would recommend using a self-etching primer such as https://www.bunnings.com.au/dulux-300g-metalshield-etch-primer-spraypak-light-grey_p1400935 . This is designed to bond to aluminium and will provide a much better foundation for the topcoat than a standard primer alone. Areas where paint is still well adhered should not be etch primed, they should be simply cleaned up and painted over.

Once the primer has dried, you can then apply your topcoat. Generally speaking, it is best to stick with the same paint system, so I would recommend using your choice of topcoat from the Dulux Metalshield range.

The key to a long-lasting finish is preparation. Clean thoroughly, sand well, use an etch primer on any bare aluminium, and then follow up with the recommended topcoat. That will give you the best chance of achieving a durable finish that won't peel or flake prematurely.

Check out https://www.bunnings.com.au/diy-advice/diy-skills/painting/how-to-paint-window-frames for some further guidance and let me know if you have any questions.

Jacob