Aluminium 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 painted on, the metal will be protected 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 any other metal structure that needs a new splash of paint, fear not. While painting aluminium differs from painting wood or masonry, it’s pretty straightforward once you know the basics.
Whether you’re a first-timer painting aluminium shelves or a seasoned pro painting aluminium gutters, it helps to go through the necessary steps for getting the job done:
Supplies You’ll Need to Paint Aluminium
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
- Gloves
- Eye protection (safety glasses, face shield)
- Air Respirator with organic vapour cartridges to keep out paint fumes
- Sandpaper
- Spray gun, roller or brush
- Self-Etching primer
- Clean cloth
- Enamel Sealant
- Latex or acrylic paint
How to Paint Aluminium – Step by Step
Step One – Clean Thoroughly
First, work in an area that’s well vented and start by placing drop cloths under your aluminium structure to prevent accidental drips. Paint splatters and drips happen frequently, so ensure you have the drop cloths ready.
To clean your aluminium, 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 Aluminium for a Coarse Finish
Sanding your aluminium 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 aluminium dust is dangerous for your lungs.
Begin sanding your aluminium 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 aluminium 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 aluminium coat has dried, proceed to sand again with 400-grit sandpaper and wipe away any residue with a cloth.
Step Four – Applying the Paint
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 aluminium 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 aluminium 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.Stripping old paint off aluminium and other metal
You only need to strip aluminium back to bare metal when the old paint is failing. Sound paint can be cleaned, sanded and primed, which is what the steps above do. Where paint is flaking or peeling, take the loose paint off first with a scraper or a wire brush, using a brush that suits the metal so you don’t scratch it.
For heavy build-up, a chemical stripper is the next step. Directions differ between products, so follow the label. Apply it, wait until the paint bubbles or ripples, then scrape it off and repeat if any is left. Test any method on a small hidden spot first. Strippers are flammable and the fumes are harmful, so wear gloves, goggles and a respirator and work with plenty of airflow.
Test old paint for lead before you scrape or sand it. Paint with high levels of lead was used in many Australian houses before 1970, and the danger is the dust you breathe in during renovation work. If your Melbourne home or the piece itself is that old, find out what’s on it first. Once the metal is bare, wipe it with white spirit on a clean cloth to lift grease and paint residue, then go back to Step One.
Getting paint off the glass in aluminium window frames
Painting aluminium window frames usually leaves a few specks on the glass. Soften them before you scrape. Wipe on warm water with a little dish soap, or a rag soaked in warm white vinegar until the paint softens. Use warm, not boiled. We’d skip any method that has you microwaving vinegar and then carrying it around, because it’s an easy way to get burnt.
Then use a razor scraper on the wet glass. Hold the blade at about 45 degrees and push it in one direction with slow, smooth strokes. Working it back and forth can chip or scratch the glass, so lift the blade and start again instead. Rinse off the residue, squeegee the glass and dry it with a cloth.
On textured or frosted glass, a razor won’t reach into the grooves. Use a soft toothbrush with warm soapy water on small splatters. For stubborn paint, apply vinegar and lift it out with a soft-bristle brush.
If a Melbourne window has a lot of paint on the glass, or you can’t get at it safely, it’s a job to leave to a painter.
