Do you have items in your home that are anodized aluminum? Perhaps you would like to give them a new look with a coat of paint but are not sure if you can paint anodized surfaces.
The good news is that you can paint anodized aluminum. However, you need to follow the correct steps or you may end up with adhesion or pigmentation issues. Painting without preparation will also mean that the anodized surface will not hold the paint well.
In this article, we guide you through the process of painting anodized aluminum in easy-to-follow steps so you can refresh your objects and get a long-lasting, great-looking finish.
Can Anodized Aluminum be Painted?
What is Anodized Aluminum?
Before you start your painting project, it is useful to understand some basics about anodized aluminum. The anodized layer is created when the metal is put into an electrolytic solution. The layer gives the anodized object enhanced functions and visual effects making it extremely durable yet lighter than copper or stainless steel.
The anodized layer is like a seal that makes the product more resistant to corrosion and helps the metal to retain its natural appearance. It prevents it from scratching, chipping, flaking, and peeling. Anodized aluminum products make great insulators and they are environmentally friendly.
Where is Anodized Aluminum Used?
There are three main industries that use anodized aluminum, which are consumer goods production, construction and architecture, and manufacturing of mechanical components. When used for consumer goods, anodized aluminum can be found in, for example, jewelry, sporting goods, and food preparation.
In the construction and architecture sector, it is used in many ways. Some common uses for this highly weather-resistant material include decorative artwork, structural components, and a range of building components for residential and commercial buildings.
Mechanical components made from anodized aluminum are used in many motor vehicles, including cars, tractors, and boats.
The Anodization Process
The anodizing process is designed to give an object a protective layer. During the process, the aluminum parts are submerged in the electrolytic solution, which releases oxygen on the metal’s surface gathering aluminum oxide.
This is an electrochemical process where the negatively charged plates attract the positive ions and the aluminum parts, which are the positive anode, attract the negative ions. This process opens the pores on the aluminum surface and this leads to the positive ions escaping while the negative ions form a barrier layer.
The result is a protective coating that makes the object more durable compared to something made of bare aluminum.
Preparing Aluminum That Has Been Anodized For Painting
For your painting process to be a success, it is important to prepare the surface carefully first. You will need:
- Dish soap
- A coarse brush
- Paint thinner
- Metal scrubber
- Fine sandpaper
It is also recommended that you wear gloves and a mask when removing the old paint to avoid touching the thinner or breathing in old paint particles.
Here is how you prepare the aluminum for painting.
Step One: Clean
When you are painting aluminum, you need to start by cleaning it with a coarse brush and dish soap. Removing dirt, particles, and debris will make it easier to paint and give you a smoother finish.
Paint will adhere much better to a clean surface and give it a more durable finish. After cleaning, make sure to dry the surface carefully before moving on to step two.
Step Two: Remove Old Paint
If the aluminum has been painted before, you need to remove the old paint. Wearing your mask and gloves apply paint thinner on the old paint. Then remove all of the old paint using a metal scrubber. Rinse the surface thoroughly with water when you have removed all the paint.
If you would like to remove the anodized layer, you can use oven cleaner as shown in this video.
Step Three: Sandpapering
Once the aluminum object is washed and dried, it is time to go over it with sandpaper. Use fine-grit sandpaper for this part of the preparation process. Using sandpaper will give you a smooth surface that the paint will easily cling to. When finished, wipe the dust from sanding away with a damp cloth.
Step Four: Degrease
It is important to remove any oil or grease from the surface you want to paint. Using a degreaser will help the paint adhere to the aluminum better. After degreasing, rinse the object and dry it again thoroughly.
Step Five: Primer
The final preparation step is to apply an etching primer that has been designed for aluminum. Priming the surface before painting will give you a smoother finish that will last longer. Ensure the primer is completely dry before you begin painting. This will take approximately two hours.
Prepare Your Paintbrush
If you are using an old paintbrush for the project, you can prepare it while the primer dries. You need to clean the brush thoroughly. Mineral spirits work well for cleaning brushes. You should wash the brush at least three times to ensure all debris and dust particles are removed.
How to Painting The Surface of The Anodized Aluminum Object?
After you have prepared the surface, there are only two more steps to finish the process.
Step One: Paint
When the primer and your paintbrush have dried, it is time to paint your aluminum object. Use the paintbrush to apply a thick coat of paint all over the aluminum surface. You will need several coats of paint. Usually, three coats will give you a great color consistency. However, you may need more coats if you are using light-colored paint.
Check how long the paint needs to dry between coats. Usually, it will be around two hours, but it can vary. Ensure the previous coat is perfectly dry before applying the next one.
Step Two: Check
When you have finished the final coat of paint and it has completely dried, it is time to double-check the result. Scan the object throughout for any uneven areas. If there are areas where the paint is not even, touch it up with another layer of paint.
Expert Tips on Painting:
- It is possible to use latex paint on aluminum. However, oil-based paints work better. They are faster to apply and will give you a smoother finish.
- Consider choosing a deep paint color rather than light-colored paint. You will need fewer coatings with deeper colors.
- Never paint over old paint. You will end up wasting your new paint and it may even ruin the surface.
- Work with patience and let the primer or previous coat of paint dry properly before applying the next one. If the primer or paint is not fully dry, you may end up with smudges or a streaky surface.
What Kind of Paint is Best For Anodized Aluminum?
You need to choose the paint you use for your painting project carefully because not all paints are suitable for anodized surfaces. An oil-based paint will work best when you are painting clear anodized aluminum. It has better adhesion because it seeps into the pores more easily.
What are the Popular Paint Colors For Anodized Surfaces?
There are some colors that are commonly used on anodized products. A pre-painted anodized object is likely to come in dark shades of red, green, blue, purple, orange, or black. ‘
Other standard colors include champagne, light bronze, dark bronze, and clear tones. These color options are more likely to create the desired consistency on the finished product.
Can You Use Spray Paint?
Using spray paint can be a quick way to paint, especially if you have to cover larger surfaces. it is possible to spray paint anodized objects and in some cases, it can work well.
However, an anodized finish may not be ideal for spray paints and can result in an uneven or poor finish. You should only use spray paint on anodized surfaces if you have expertise with them.
Can Paint Damage The Anodize Layer?
Painting your anodized item with suitable paint will not damage it. The most common cause of damage is harsh chemicals such as solvents. Some paints may include chemicals that can break down the protective layer. This is why it is very important to check the paint is suitable for anodized surfaces.
If you are not sure if the paint you have is suitable, test it first on a small discrete area. Leave the paint to dry and check the results. If all looks good, you are good to proceed with the whole object.
When you want to paint an aluminum object that has been anodized, it is important to prepare it well before painting. Oil-based paints and deeper colors work best on aluminum surfaces. You will likely need several coats of paint to get the best finish. Remember that the paint needs to dry thoroughly between each coat.
Hopefully, this article has helped you to give your old anodized aluminum objects a fresh look with new paint. If you would like to ask anything about painting anodized aluminum, you can write your questions in the comments box.