Can aluminium be painted?

Yes, but it needs an epoxy etch primer or adhesion primer specifically for non-ferrous metals.

Aluminium: Preparation and Adhesion

Why aluminium peels easily and how to ensure absolute adhesion.

Infographic: The smooth surface of aluminium and the oxide layer that prevents paint adhesion.

Why does paint peel off aluminium?

Aluminium is smooth as glass and lacks pores for paint to "hook" onto. Furthermore, it instantly develops a transparent oxide layer which, while protecting it from corrosion, acts as a non-stick surface for common paints.

🪞 Non-Porous Nature

Unlike plaster or wood, aluminium requires chemical "biting" (etching) to create adhesion.

💧 Passivation Oils

Aluminium profiles leave the factory with industrial oils. If thorough degreasing with nitro thinner is not performed, failure is guaranteed.

Filiform Corrosion (Worm-like Corrosion)

The hidden enemy of aluminium! It appears as raised "worms" or "veins" under the paint, pushing and blistering the film.

It typically starts from scratches or sharp edges where moisture and salt penetrate under the paint. It is extremely common in coastal areas with humidity above 75%.

Infographic: Corrosion looking like worms under aluminium paint in coastal areas.

The Secret of Adhesion: Wash Primer

Infographic: The 4 steps to painting aluminium - degreasing, matting, wash primer, topcoat.

Forget common rust inhibitors. Aluminium requires Wash Primer - a specialized primer that chemically "bites" the metal.

1️⃣ Degreasing

Clean thoroughly with nitro thinner. Do not sand before cleaning, as you will push oils into the metal.

2️⃣ Light Sanding (Matting)

Use fine sandpaper (P220) or Scotch-Brite to remove the gloss and create a "tooth."

3️⃣ Wash Primer (Self-Etching)

The most critical stage. Wash Primer creates an unbreakable chemical bond with the aluminium.

4️⃣ Topcoat

After 1 hour, apply water-based enamel or 2-component polyurethane for maximum durability.

Industrial Painting & Seaside Class

For architectural projects near the sea, simple electrostatic powder coating is not enough. The Qualicoat Seaside Class specification mandates deeper chemical preparation (etching).

This process removes more of the aluminium surface layer, ensuring the powder "locks" onto clean metal, preventing filiform corrosion.

Infographic: Qualicoat Seaside Class certification for coastal constructions.

Painting Galvanised Surfaces Surface Preparation Before Painting Metal Primers: Which and When?

Metal Painting & Anti-Corrosion Protection

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Central Guide

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📚 Paint Guide

Return to the main metal painting guide.

📞 Technical Support

Planning to change the color of your old aluminium frames?