It is common for aluminium window frames to be anodized.
When the surface is anodized, it means the material has been coated with a protective oxide finish to keep it strong and durable for a long time (usually up to 10-20 years).
Sometimes aluminum frames are powder-coated, but many contractors have found that anodizing the frames is a much better option, especially when people at home need to open and close their windows all the time.
The anodized protective oxide layer in this case allows the frames to resist the constant physical abuse they incur daily.
Can You Paint Anodised Aluminium?
Yes, it is possible to paint your anodized aluminium frames.
But remember, it is not as easy as slapping a new coat of paint over the protective oxide layer of the frames.
You will need to prepare the anodized aluminium frames properly before you start painting them.
If you don’t prepare the frames correctly, then it will be challenging to get the paint to stick to them.
Why Painting Anodized Aluminium is Not the Best Option?
Although it is possible to paint over the anodized aluminium window and door frames, it is not the best option most of the time.
This is generally due to the fact that anodised aluminium does not have any pores, which is why paint has such a tough time sticking to it.
Experts only recommend painting anodized aluminium frames if you notice corrosion forming on the surface of them.
Corrosion may develop due to pitting or dents in the frames. You must paint over these areas to stop the corrosion from occurring again.
Alternatively, you don’t even need to paint over the surface to protect it from corrosion.
After you remove the existing corrosion, you can simply add an invisible protective coating to the aluminum surface, such as a metal resurfacing solution.
Then you won’t even need to mess with the paint option.
But if you don’t like the color of the frames, then paint is still the only option.
Just be prepared to perform maintenance on the painted surface of your anodized aluminium window frames every few years.
That is about the time when the paint starts to deteriorate and chip away.
You’ll have to remove the old loose paint first before you can repaint it.
How to Paint Anodized Aluminium Window Frames Safely?
Aluminum is usually anodized with different colors like green, blue, red, brown, etc.
Particularly, if you don’t like the current color of your anodized window frames, then you’ll obviously need to paint them a different color.
If you’ve decided that you want to paint your anodized aluminium window frames, despite the objections of experts, then you need to do it safely.
Below are the four main steps for painting your anodized aluminium window frames safely.
Step 1) Clean the Anodized Aluminium Surface
You should never begin any paint job without cleaning the surface of the material first.
Anodized aluminum frames can be cleaned with a simple scrubbing brush, warm water, and dish soap.
Once you have these materials, mix the warm water and dish soap together in a bucket.
Dip the bristles of the brush into the mixture solution and begin scrubbing the surface of the frames with the brush.
When the surface looks clean, rinse off all the soapy water and wipe it down with a damp sponge.
Now give the surface some time to dry completely.
Step 2) Remove the Old Paint
If you are repainting the old already painted aluminum window frames, make sure that you remove the dried paint very carefully before repainting.
This will prevent the paint from peeling away faster.
IMO, the best way to remove paint from an aluminum window frame is by using aircraft-quality paint thinner which is mostly available at auto parts stores.
- Wear the gloves and apply the paint thinner to the frame
- Using a metal scrubbing pad rub the thinner lightly into the frame to scrub off the paint
- Wait for 2-3 minutes and rinse the paint thinner with clean water
Remember that while removing the paint with thinner, you should not leave the thinner on the surface for long.
This can break down the metal in the window and cause damage.
Step 3) Apply the Primer
Etching primer is a special type of primer that makes it easier for the paint to stick to metal surfaces.
Pour about 1 gallon of etching primer into a pot or bucket. Don’t fill the container up more than two-thirds of the way.
Using a paintbrush that is between 2 inches and 4 inches long, apply the primer to the surface of the frames.
After you apply the primer, give it two hours to dry before moving on to the next step.
Step 4) Clean the Brush
Mineral spirits can be used to clean the paintbrush.
All the primer needs to be removed from the bristles before you use the brush for painting.
Of course, you can use another brush for that too. But you still need to clean the primer brush either way.
Step 5) Paint the Aluminum Surface
Oil-based paint should be used for the clear anodized aluminum frames.
Also, it’s good to choose eggshell or matt paint finishes as these can do better at withstanding the heat in the sun.
Glossy finishes are often good for cooler climates.
Pour the paint into a container about two-thirds of the way.
Dip the bristles of the paintbrush into the paint and begin painting over the surface of the anodized aluminum frames.
When you’re done applying the coat of paint, wait two hours for it to dry.
You may need to apply more coats of paint afterward. If so, wait two hours in between coat applications.
Can You Dye Anodized Aluminum with Different Colors?
Yes, you can dye an already anodized metal surface with colors like black (called black anodizing).
But it should be done only before the final sealing stage of anodizing.
The process will generally include immersing the metal part in a liquid solution containing the dissolved dye.
The porous hard-anodized aluminum coating will absorb the dye and get the intensity of the color depending on the factors like dye concentration, the thickness of the anodic film, the time for which the metal is immersed, and the temperature of immersion.
Besides painting and dying, there are a few other ways by which you can color aluminum and these include:
- Integral Coloring
- Electrolytic Coloring
- Interference Coloring
Regardless of what method you use for coloring the anodized aluminum, cleaning, polishing, and de-anodizing your aluminum is important if you have scratches and fading effects on the surface.
This will help to keep the bright natural sheen of the metal intact.
The Bottom Line
Anodized aluminum is attractive, durable, and long-lasting – no matter it’s on your window frames, home appliances, or cookware in the kitchen.
However, if you want to change the appearance, you can paint or dye it with a different color.
Make sure you use the right etching primer and then an oil-based paint so that you can paint the surface without any adhesion issues.
Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.