Powder coating is an alternative to liquid coating, which was a huge environmental problem. Today, various aluminium items have powder coating in the architectural, construction, and interior world. While the coating has a durable paint finish, painting over it may be necessary to refresh the colour or to change the look of your home.
Can You Paint Powder Coated Aluminium Windows?
Yes. Powder coated aluminium windows can be painted if you clean and degrease them, remove any corrosion, lightly sand the coating to give a key, apply an aluminium-compatible primer and finish with thin coats of a suitable topcoat. Professional re-powder coating lasts longest but means removing the frames.
Powder coating is a dry powder that is electrostatically applied to a metal surface, such as aluminium. The base metal is coated with powder and heated in an oven to melt the coating onto the aluminium.
The intense heat provided by the oven changes the powder into a smooth layer of coating that sticks to the windows during the curing process. The dry powder elements are boosted through a chemical process while it is cured. Powder-coated surfaces have a durable finish and last for quite some time.
You can definitely paint on a powder-coated window, which saves you time and money in the long run. Instead of taking your windows to get another powder coat, which may take longer, you can quickly apply paint. There is also no inconvenience of moving very large items.
Painting over existing powder coating is often more cost effective than getting a new coating. Over time, powder-coated aluminium can begin to bubble, crack or flake off. So, painting over the powder coating will protect the windows and improve the metal surface appearance.
How Do You Paint Over Powder Coated Aluminium Windows?
Clean and degrease the frames, treat any corrosion, sand to remove the gloss, mask the glass and surrounding areas, apply an aluminium primer, then spray several thin top coats, letting each dry before the next.
It is easy to paint over powder coating. You can follow these steps to paint a powder-coated surface with liquid paint successfully.
Step 1: Clean and Degrease the Frames
Any grease or dirt on the powder-coated metal surface will prevent the paint from clinging, so all the debris and other contaminants must be removed. You can wash the window using a soft brush or use the hose if the window is very dirty. If you are using degreasing detergent, you must ensure it is rinsed off with warm water (not hot) and left to completely dry before continuing.
Step 2: Remove Any Corrosion
The powder coating on your windows may have corroded, so you must strip the rust before painting. If your coating is chalky, you must remove the white rust with a nylon pad. For heavier corrosion or flaking coating, you can use a power sander to make the surface smooth. Wipe the surface with tack cloths to clean any remaining dust.
Step 3: Sand (Abrade) the Surface
When you paint over powder coatings, you must make sure that the coat of paint sticks to the aluminium. You have to use sanding to remove the gloss from the powder coating, and fine grade abrasive paper is a good hand-prep option for creating a nice surface to apply the paint. If your frames have cement or mortar splashes, see our guide on removing cement from aluminium windows first.
Anodised aluminium needs more abrading than normal ones. If some parts of the powder coating are still there, feather the edges so the surface is smooth. Clean any residue left after sanding.
Step 4: Mask Surrounding Surfaces
Mask any surfaces that must be protected from the primer or liquid paint. You can use plastic sheeting, tape, and masking paper to protect the finished surfaces from being overpainted.
Step 5: Apply an Aluminium Primer
Once your windows are clean and dry, you can apply the primer and leave it to cure. You should do this as soon as possible, so the window does not get dirty or oxidise again. There are various primers for different types of alloys, so a special primer for aluminium must be used.
Apply a small amount of the primer to the surface to check if it sticks. If it smudges or can be wiped off, you must repeat step three.
Step 6: Spray Thin Top Coats
There is a wide range of topcoats available to suit your needs. You can choose your desired colour and gloss levels suitable for painting over powder coating. Selecting the correct product so it sticks to the surface is essential.
You must hold the can between 10cm and 25cm away from the windows. Use various thin coats for each application rather than putting a thick coat on the window frame. The coat will peel off quickly and become untidy. If you're applying liquid paint, this is especially important.
When you're finished painting the window frames, your clean-up should be minimal. If you did not use a primer, you must choose the top layer to stick to the primer or to the aluminium. After painting, you can read our tips on sealing aluminium doors and windows to keep them weathertight.
How Long Do Aluminium Doors and Windows Last With Proper Maintenance?
Well-maintained aluminium windows and doors typically last 30–40 years, and a good powder coat around 20 years or more. Clean the frames every few months with mild soapy water, keep drainage channels clear and lubricate hinges and locks once or twice a year. Our guide to removing scratches from aluminium window frames covers minor damage.
It is hard to tell how long your windows will last; however, their life can be prolonged with regular cleaning and maintenance. Whether you're calling a professional or doing it yourself, you must have a routine for cleaning and maintenance to ensure you get the best out of your aluminium.
At Aluminium Living, we supply made-to-measure aluminium bifold doors, sliding doors and French doors, factory powder coated in a wide choice of colours. Use our online door designer to choose your configuration and colour.
Painting Powder Coated Aluminium FAQs
What kind of paint do you use on powder coating?
We recommend epoxy, thermosetting acrylic, polyester, or polyurethane enamels. Air-drying enamels such as aerosol spray can paint can also work well, but they may not provide the same quality.
How long does powder coating last on aluminium?
Powder coating can last for 20 years; however, exposure to UV light and other elements can break it down more rapidly.
Can you touch up the paint on the powder coating?
You can touch it up with liquid paint. Do not touch up with powder, as it will leave a visible line between the coated area and the area you touched up.
Can aluminium windows be resprayed in situ?
Yes. Specialist on-site spraying companies can clean, prime and respray aluminium windows and doors without removing them, masking the glass and surrounding walls. It's a popular way to change colour – for example from white or brown to anthracite grey – for far less than replacing the windows.
Do you need to prime powder coated aluminium before painting?
Yes. Paint doesn't bond well to glossy powder coating on its own, so after sanding you should use a primer designed for aluminium or non-ferrous metals. Test a small area first: if the primer wipes off, sand again before continuing.
Can you paint uPVC windows the same way?
The process is similar, but uPVC needs a uPVC-specific primer or paint. If you're weighing up materials, see are aluminium windows better than uPVC?
Can you paint an aluminium sliding patio door the same way?
Yes. The same clean, key, prime and top-coat process works on aluminium patio door frames, but you also need to protect the rollers, tracks and seals and leave the door open until the paint has fully cured. Our guide on how to paint a sliding patio door covers each step.
