Anodizing (anodic oxidation)
An oxide layer grown electrochemically on the aluminium surface. Thickness classes are defined in EN 12373 (e.g. AA10, AA15, AA20, AA25); Qualanod is the known quality scheme. Natural silver or coloured options exist.
Surface and secondary finishes
The surface finish determines appearance, corrosion resistance and service life. Scope is confirmed in writing in the quote.
The two most common finishes are anodizing and electrostatic powder coating. Anodizing is an oxide layer integral with the surface that keeps the metallic look; powder coating is a polymer coating offering a wide colour range.
Electrostatic powder coating
A polymer coating applied electrostatically and baked. The RAL colour range and matt/gloss finishes are possible; Qualicoat is the known quality specification. Separate classes exist for coastal and severe environments.
Wood-grain effect coating
A decorative coating that gives a wood look to a powder-coated surface by heat transfer.
Machining
Secondary work such as cutting to length, drilling, milling and bending; dimensions and tolerances should be stated on the drawing.
Which to choose?
- Metallic look and surface-integral hardness: anodizing.
- A specific colour (RAL): powder coating.
- Outdoor or coastal exposure: the required coating class should be stated in writing in the quote.
- A wood look: wood-grain coating.