How to Paint Aluminum: A Comprehensive Guide
Aluminum is a very hard and durable material, making it a good choice for many home projects, including shutters and gutters. And once it has been improved with paint, it will protect from sun and rain for many years to come. It’s also relatively light as far as other metals go, so it’s easy to work with.
If you have exterior siding, window frames, or other metal structure that has been standing for a while without being painted, fear not. While painting aluminum differs from painting wood or masonry, it’s pretty straightforward once you know the basics.
Whether you’re a first-timer painting aluminum shelves or a seasoned veteran of painting aluminum gutters, it helps to go through the necessary steps for getting the job done.
Supplies You’ll Need on Hand to Paint Aluminum
Painting aluminium can be a bit more involved than painting other materials. And since you’re handling self-etching primers and rough surfaces, it’s essential to take some extra precautions to prevent damage or injury.
Before getting the old paintbrush out and diving in headfirst, here are some supplies you’ll need to have on hand.
- Drop cloth
- Eye protection (safety glasses, face shield)
- Air Respirator with organic vapour cartridges to keep out paint fumes
- Spray gun, roller or brush
- Self-Etching primer
- Clean cloth
- Enamel Sealant
- Latex or acrylic paint
Painting Aluminum the Right Way
Step One – Clean Thoroughly
First, you’ll need to find an area that’s well vented and place drop cloths under your aluminum structure to prevent any accidental drips. Paint splatters and drips happen frequently, so ensure you have the drop cloths ready for this possibility.
To clean your aluminum, mix some warm water with a mild detergent or degreasing cleaner in a bucket and dip a clean cloth. Wipe any dirt or grime, and rinse with clear water to remove all traces of soap residue. If there are flakes of paint, gently scrub with a wire brush to remove.
Step Two – Sanding Your Aluminum for a Coarse Finish
Sanding your aluminum is an essential step for creating adhesion between the surface and paint. Sanded surfaces are rough to touch, so you’ll need to wear your gloves, respirator and eye protection during this step. If you’re using a power sander, it’s even more critical to use a respiration mask as inhaling aluminum dust is dangerous for your lungs.
Begin sanding your aluminum with fine grit sandpaper, around 60 to 80 grit. This will remove old paint quickly and provide the roughest surface for the new paint to grip onto. Once you’re done, wash the surface thoroughly with the same solution mentioned in step one and leave it to dry.
Step Three – Apply Self Etching Primer in Multiple Coats
Once your aluminum surface is clean and dry, it’s time to apply a Self Etching Primer. Apply 3-4 coats of primer, ensuring you have a solid layer to work with. If you’re spraying your primer, the ideal place to do this is in a well-ventilated garage or outdoors where fumes can quickly dissipate.
Drying times between coats will depend on the primer and the air temperature, but in most cases, you can expect to wait around 5 minutes between them. Always read the directions to verify the recommended drying time before you apply each coat. Once your final aluminum coat has dried, proceed to sand again with 400-grit sandpaper and wipe away any residue with a cloth.
Step Four – Applying the Paint
You’ve finally prepared your aluminum piece, and now it’s time to apply your paint. Choose your favourite paint colour, and ensure it can be applied to metal surfaces. Apply 4-5 coats of latex or acrylic paint to your aluminum, and allow it to dry and cure for 24 hours before exposing it to water or any other type of harsh weather.
We recommend a matte or satin finish for aluminum, as they hide wear and tear better than high gloss. Matts paints are also ideal if your object is outside and exposed to the sun as they’re more reflective and can withstand high temperatures.
Step Five – Apply Your Enamel Sealer
Once your paint has dried and cured, it’s time to apply a coat of enamel sealer. This is an optional step, but we recommend applying the final layer as this will protect your paint from damage and discolouration due to UV rays.
Dip a clean cloth into the enamel sealant and let any excess drip off before wiping the surface. Allow the enamel sealant to dry, and then apply a second coat. Once the sealer has dried, you can bring your aluminum piece back inside and enjoy all its new beauty.
You may need to make a few touch-ups here and there, but the process will become easier over time.
Step Six – Cleaning up After Painting
Your aluminum paint job is finished, but you still need to clean up! Be sure to thoroughly wash any excess paint from paint brushes with warm water and keep your painting cans open until the paint has completely solidified. Afterwards, you will be able to dispose of the latex paint in your regular trash as they are non-hazardous.
An FAQ to Paint Aluminum
Painting aluminum can be a little tricky, but it doesn’t have to be! Let’s unravel any preconceptions about the process and answer some of the most common questions we get from our customers.
Can you Paint Straight onto Aluminium without Prep?
Yes, but we wouldn’t recommend it. Painting your Aluminium piece without priming and sanding can result in a lower quality finish and paint that peels off easily. Aluminium, unlike wood, for example, is a non-porous surface and cannot soak up paint.
For a paint job that will last the long haul, always prime and sand your aluminum before painting.
Should You Use a Spray Paint Gun, Paint Brush or Roller to Apply Your Paint?
Spray Paint Guns
Your paint application choice will depend on the size of your aluminum surface. If you are painting a large area, we recommend using an HVLP paint spray paint gun to ensure even application with less effort.
Spray guns can be on the more expensive side, though, so if you’re painting a small surface like your garden furniture, consider a paintbrush.
For smaller pieces, applying by hand brush is ideal. Paint brushes are cheap, easy to find and come in various sizes for all different applications. A brush also allows you to paint in more detail and design than a spray paint gun, as its dexterity makes it easy to apply thin coats and paint intricate patterns.
In the case of rollers, you’ll want to find one that’s similar in size to the surface area you’re about to paint. Find a slightly smaller roller or the same size as your aluminum piece to ensure a good fit. Rollers provide an efficient and consistent application but lack the precision of a paintbrush.
Exterior Painting Services with NewLine Painting
Do you have aluminum siding on your property that needs to be painted? If so, NewLine Painting is the company for you! We provide exterior painting services in Melbourne and can take care of your painting needs from start to finish.
Our team is experienced with a wide range of exterior surfaces, including all things aluminum. We’ll make sure your home’s surface is prepped and ready for paint before we get to work, using only the best methods and products to ensure a high-quality finish that will last years after completion!
Contact us today for a free quote, and let us help you spruce up the outside of your home!