How do I paint over exterior powder coated window frames?

[Trickytrevor]

Hi, I want to paint over my exterior powder coated aluminium window frames. They are currently mission brown and in generally fair condition. My house is about 35 years old and faces east west. I generally like to use British Paints products but I'm open to any suggestions about other brands ie Dulux, Taubmans. I will be using a white topcoat. This is to match white plantation shutters to be fitted later this year. The biggest problem I'm finding is reliable information for metal primers and matching topcoats. As the work will be all brushwork, I need some advice on good quality brushes as well.

[JacobZ · Accepted solution]

Hi @Trickytrevor,

Thank you for your question and welcome to the Bunnings Workshop community, it is great to have you with us.

I suggest starting by assessing the condition of the existing powder coat before beginning. If the surface has a powdery texture it will need to be washed and cleaned with a stiff bristled brush and soapy water.   

After that first wash grab a Scotch-Brite 155 x 100mm Heavy Duty Scourer Pad and thoroughly scrub the entire surface. Rinse the area with fresh water and allow it to dry. Once it has dried, test the surface by running your finger across it to check for any remaining powdery residue. 

Repeat this procedure until there is no longer any powder residue on your fingers. Perform a final wash using sugar soap, followed by rinsing with clean water and allowing the surface to dry.

The most important step to ensure a good quality, lasting finish is the primer. I'd advise using White Knight Rust Guard Grey Quick Dry True Bite Primer Paint, allowing it to fully dry then applying White Knight 4L White Satin Rust Guard Quick Dry Advanced Enamel Paint which can be tinted to a colour of your choosing.

For a good quality brush, I'd advise the Monarch 50mm Moulding And Skirting Synthetic Paint Brush for this application as it will allow you to be nice and accurate and will give a smooth finish.

Let me know if you have any other questions or need any further advice.

Jacob