If you want to change the way your window capping looks. Can you just paint it? Or do you have to replace it?

Yes, you can paint your window capping. For the best results, you will need to first wash the capping, prime it, and then apply multiple coats of aluminum-friendly or vinyl-friendly paint.

Here is everything that you should know about painting window capping.

Can you paint window capping

You should paint it in order to update its look and texture.

It Degrades Over Time

Window capping is usually made from either aluminum or vinyl. With time, these materials degrade. This often necessitates a refresh in looks.


Even though aluminum capping requires little to no maintenance, it will corrode over time. It may also rust.

Therefore, you will have to refresh its look periodically. And the most effective way of doing this is by painting it.


Vinyl window capping also degrades over time.

It loses its color after getting exposed to the sun. If this happens, covering it with a fresh coat of paint will be an easy, cheap, and convenient method of restoring its appearance.

Painting Is Often a Go-To Fix

Painting is way more affordable than installing a new window capping. It also takes little to no expertise to get the job done. And it is thus an easy and affordable fix.

Therefore, it makes sense to paint window capping if:

  • you want to create a unique texture and look
  • it is worn-out and you want to refresh its look
  • you want it to match the general feel and appearance of your home and you couldn’t get matching ones
  • the existing capping is already rusting and you need a quick fix before installing new capping

Do You Need To Paint Window Capping?

No, you don’t need to paint window capping.

This is because:

  • it is normally already weather-proofed.
  • it is usually made from easy-to-maintain materials like vinyl and aluminum. Painting will invalidate this benefit.
  • they typically come in a variety of colors, and can even be customized. You can thus always get whichever color you desire.

However, you can always opt for painting if you want to:

  • improve the aesthetic appeal of your window
  • update the protective coating of the capping so as to prolong its lifespan

What Should You Consider When Painting Window Capping?

When you are painting your window capping, you need to consider:

  • the type of material that the trim is made of
  • the type of finish you want
  • whether or not the trim was painted initially
  • the weather


Window capping is typically made from aluminum or vinyl. Not every paint can stick well on these materials. And not every paint that sticks on an aluminum surface can stick on a vinyl surface.

Therefore, when choosing paint, you need to consider the material that your capping is made of. Generally, going for acrylic paint, that is designed for exterior use, is always a safer bet.


The type of finish that you desire for the exterior of your home will also determine which paint you will end up with. You should choose a finish that:

is easy to clean and maintain

is forgiving in terms of showing imperfections

Old Paint

If the window capping has old and peeling paint, you will need to remove it first before applying a new coat of paint.

Old Paint Removal Is Necessary

Failure to do so will lead to an uneven finish. It will also increase the likelihood of premature peeling and cracking.

Therefore, if you want aesthetically pleasing and long-lasting results, you will need to add an extra step when dealing with capping that was initially painted.

Sand, Wash and Dry

This extra process typically involves sanding the paint off the surface. And then washing the capping with soapy water. Thereafter, give it time to dry before moving on to the next step.


You will have to make sure that you paint the window capping when there is good weather. Moderate weather is the best weather to paint in.


If you paint in hot weather, you will be painting on window capping material that has expanded. When it eventually contracts, it will cause the paintwork to develop bubbles. And with time, it will peel off.


Painting during extremely cold weather is already a bad idea since the capping contracts in the cold. And so painting it at this stage will only lead to unnecessary strain on the paintwork as the capping will eventually expand and resume its normal state.


You shouldn’t also paint when it is raining. This is because it introduces a moisture component in the paintwork. This will eventually lead to a higher chance of premature peeling.

Color Effect

When choosing paint, you have to pay attention to its color. Why? Because paint color plays a significant role in determining the longevity of vinyl window capping.

Vinyl tends to crack easily when it is exposed to extreme heat.

Therefore, if your capping is made of vinyl, you will need to choose lighter shades of paint. This is because if you opt for dark-colored paint, the paint will absorb a lot of heat. This will then accelerate the rate at which the vinyl capping will degrade.

Painting Window Capping: Steps

The following are the steps that you should take in order to get the best results.


The first step in the process is to clean the capping.


Dirt and Debris

You will need soapy water, a sponge, and a mild detergent. You can also add a cup of bleach for even better results.

Use the mix to scrub the capping until you get rid of all traces of dirt and debris.

Dirt and debris


Over time, aluminum capping develops a chalky surface.

You need to get rid of this dust before painting. This is because if you paint over the chalky substance, it will come between the aluminum and the paint. And then this will lead to premature peeling and cracking.

To remove this powder from your window capping, you need to wash it off. A power washer is usually enough to get the jobs done. However, if it can’t, then you will need to scrub it with a mixture of TSP and diluted bleach.

After washing the capping, rinse it with fresh water. And then let it dry.


If you had initially painted the capping, you will need to remove any traces of cracking or peeling paint. Use sandpaper to scrub the surface clean.



The next step is to protect against paint splashes and drips.

Take painter’s tape and use it to cover all window areas and adjacent wall areas. Make sure that you tape around the top, sides, and bottom of the capping.



Even though priming is not mandatory, it is usually necessary if you want long-lasting and high-quality paintwork.

Why? Because the primer:

  • enhances the bonds between the paint and the capping surface
  • blocks stains and other imperfections, guaranteeing a smoother finish.

Therefore, you should purchase a vinyl-friendly or aluminum-friendly primer –depending on which material your window capping is made of — and apply it using long brush strokes.

After you are done, give the primer enough time to dry.

Note: As far as primers for aluminum capping go, you should go for ones that have been specifically designed for metal surface application. Using a self-etching primer is often recommended. Making sure that the primer is also specifically designed for exterior use will also help to guarantee long-lasting paintwork.



After the primer dries up, the capping surface will be ready to receive its first coat of paint.


Choose Your Paint

Start by carefully choosing your paint. This is because the paint that you use will play a significant role in determining the end result that you get.

It will determine:

  • how long the paint will last
  • how easy it will be to maintain
  • the overall look and feel of the paintwork

Generally, you should choose exterior paint that sticks well to vinyl or aluminum surfaces.

Vinyl Window Capping

The best paint to use on a vinyl window capping is:

  • acrylic paint
  • that is specifically designed for use outside
  • lighter-colored paint. Dark colors readily absorb heat and this can accelerate deterioration.

Aluminum Window Capping

The best paint to use on aluminum window capping is:

  • acrylic latex paint
  • that is specially designed for exterior use
  • and which has a flat or satin finish

Apply Multiple Coats

Pour the paint into a container, and then start applying it with long strokes. Apply the first thin coat. Give it time to dry. And then apply the next coat.

When applying the paint, you need to keep in mind that:

  • aluminum heats up in direct sunlight. This will cause a faster setting. Therefore, using thinner coats is advisable.
  • in order to avoid an uneven finish, and to guarantee a smoother one, you should use as little paint as possible. This is because too much paint will simply lead to splashes, drips, and streaks.
  • painting from the top to the bottom will make your work easier. This is because it will ensure that the paint drips into unpainted sections, as opposed to already-painted sections.
  • an airless sprayer is always a preferable method of applying paint. It allows for faster painting. It also makes it easier to apply thinner coats.

Removing Tape

After the paint dries, start the clean-up process by removing the masking tape from the window and other adjacent areas.

Take any brushes that you used and wash them with running water. Wash off any paint splashes from the floor, window, or any unprotected items. And if you had covered your floors with plastic sheeting, remove it.

Removing tape


No, you don’t have to always use a primer when painting aluminum capping.

However, while priming the window capping is not a must, it is necessary for high-quality paintwork. This is because it enhances the bonds between the paint and the aluminum surface. It also smoothes over blemishes, something that usually guarantees an even finish.

You only need two coats of paint. The first base coat. And a second finishing coat. This is so especially if you are using a good primer.

However, you can always use multiple coats, especially if you are using thin coats.

You should replace window capping if it has visible structural damage. If it has developed holes, significant cracks, or is worn out to the point where it can no longer shield the trim from the elements, then you should replace it.

However, when considering the paint or replace option, replacing isn’t always the best option.

If you simply want to refresh its appearance, then you should simply paint it. Painting is a cheaper and simpler way of changing its appearance. It is thus the recommended method of fixing window capping that has minor cosmetic defects.

Ben McInerney
Author: Ben McInerney - is a qualified arborist with 15 plus years of industry experience in Arboriculture. He ran a successful tree service before turning to writing and publishing. Ben is dedicated to providing users with the most accurate up-to-date information on everything trees.