Aluminum is a popular material nowadays because it’s durable and lightweight. What’s more, the silvery-white metal can give a modern look to any room. However, some homeowners might want to paint it to match other furniture and decorations.
Panting aluminum is just like painting any other surface like plastic or wood, but there’s a key difference in the prepping stage of the process. These are the five steps that you should follow:
- Clean the metal surface thoroughly.
- Sand it with coarse-grit sandpaper, then repeat with fine-grit
- Apply self-etching primer and sand again when it’s dry.
- Apply enamel sealer (optional).
These are the basic steps for painting aluminum. If you want to know more details and get some tips to yield the best results, keep reading!
1. How to clean aluminum before painting
Whether the aluminum object or surface has a layer of old paint or merely one of dust, you should thoroughly clean it before you get started with your project.
Supplies you will need:
- Degreasing agent
- 2 clean rags or cloths
- Wire brush (for rust and flaking paint)
- Fill a bucket with warm water and add a few squirts of your degreaser of choice. You can use either a specialty product that you can find at home improvement stores or simply a grease-cutting dish soap.
- Dip a clean rag or cloth into the solution and use it to clean the aluminum object. Rinse with plain water and dry off with a clean rag or cloth. And that’s it, now the aluminum surface is ready for the next stage!
Please note that if the aluminum object is old or has been exposed to the elements, it could have formed a layer of rust or flaking paint that can prevent paint from adhering, so you need to remove that as well.
All you have to do is to scrub the object gently with a wire brush. Be careful not to apply too much pressure to avoid scratching the surface as much as possible.
Now, if we’re dealing with a full coat of old paint, there’s a whole different step that you should follow:
How to remove old paint from aluminum
- Paint stripper
- Paint scraper
- Clean rag or cloth
Move to a well-ventilated area and read the instructions on the label. In most cases, you only have to pour the solution or apply the paste onto the metal and wait a few minutes. Then, you can scrape the paint off with a paint scraper. Rinse the surface with plain water and dry off with a clean rag or cloth.
2. How to prepare aluminum before painting
Once your metal is clean and shiny, you need to sand it and prepare it for the primer.
- Safety gear (goggles, gloves, dust mask)
- Coarse-grit (80- or 100-grit) and fine-grit (400-grit) sandpaper
- Clean rag or cloth
- Degreasing agent
- Go to a well-ventilated area and put your safety gear on. The sanding process produces metal dust particles that are extremely harmful to your eyes and lungs. Protect them and your hands by wearing safety goggles, a dust mask, and work gloves. Make sure that your mask is rated for sanding dust.
- Next, take a coarse-grit sanding block or sandpaper and buff the entire metal surface, and every corner and crevice using smooth, circular motions. Wipe the dust off with a clean cloth.
- Repeat the second step, but with 400-grit sandpaper.
- Fill your bucket with warm water again and add your degreaser of choice. Rinse your aluminum object or surface with this mix and then rinse it again with plain water.
- Let it air-dry or wipe it down with a clean cloth.
3. How to prime aluminum
Now that you’ve sanded your aluminum object, you can move on to priming the surface.
During the last stage of preparing aluminum for painting, it’s essential that you get self-etching primer and not a regular paint primer, even if it says “for metal”.
Home improvement stores or auto specialty shops have self-etching primers in spray paint form readily available.
- Self-etching primer
- Fine-grit sandpaper
- Clean cloth or rag
- Safety gear
Applying primer is a piece of cake. Read the can for the ideal painting conditions and specific instructions, but most of the time all you have to do is spray the primer on in thin coats. You should apply 2 or 3 coats, depending on the manufacturer’s indications.
Next, you should wait for the recommended dry time listed on the can. It’s important to be patient and let the primer cure, otherwise, both the paint and the primer might peel.
Once cured, gently sand the piece again with 400-grit sandpaper, and wipe away the resulting dust using a clean cloth.
Remember to always wear your safety gear to protect yourself from fumes, and work outside or in a well-ventilated area.
4. How to paint aluminum
Your aluminum object is clean, sanded, primed, and finally ready for some color! Now the fun part begins.
- Masking tape
- Paint (read the following section to find out the recommended types of paint for aluminum)
- Protect yourself from paint fumes and stains. Wear your safety wear and work in a well-ventilated space.
- Take some masking tape and cover the areas that you don’t want to be painted. For large areas, you can use paper or plastic sheeting secured with masking tape. The tape should be removed only after the paint has completely dried.
- Use spray paint for easy application and better results. You can also use brush-on paint. Apply light, even coats of the paint of your choice. Make sure that all of your strokes go in the same direction to avoid an imperfect finish.
- Wait the recommended dry time between coats for your type of paint and then apply a second layer.
- Let the paint fully dry and cure for about 24 to 72 hours.
What paint to use for aluminum
Since you’ve applied the primer, you can use any type of paint you want, you don’t necessarily need a specific one for metal.
You can use acrylic or latex paint, but try to choose one with a matte or satin finish. Glossy paint is not recommended because it can bring out any imperfections like scratches and dents, which are often found in aluminum.
Keep in mind that if you’re painting an object that’s going to be left outside, you need paint that’s labeled “exterior-grade” or “outdoors”.
Spray paint is the best option for small objects because it can be applied quickly and easily. If you’re dealing with a larger surface, then brush-on paint is better.
For brush-on paint, we recommend that you use a flat, wide paintbrush made from synthetic fibers. Avoid soft camel hair brushes because the bristles don’t hold their shape, or stiff boar bristles because they might leave brush marks on the surface.
5. How to seal aluminum
This step is entirely optional. However, if your aluminum object is meant for heavy use or the outdoors, we highly recommend that you seal the paint to protect it from chipping, flaking, scratching, or fading.
Enamel comes in matte, satin, and glossy finish. Remember to avoid glossy finishes because they will highlight any imperfections.
The application process is rather simple. You only need to get some clear enamel sealer and then apply it in thin coats, letting them dry to the touch before adding the next one. You will need at least two coats.
Finally, wait between 24 to 72 hours for the enamel to cure completely.
Painting aluminum surfaces is an easy way to breathe life back into any dull-looking object.
While the painting itself is a rather straightforward process, it’s essential to follow the cleaning and prepping steps for the paint to adhere properly.
Luckily, it’s really easy to do it and we’ve even included some helpful tips in case you need to remove rust and old paint.
After reading this complete guide on how to paint aluminum, you’re more than ready to get to work and create some beautiful pieces!