Anodising vs Powder Coating: Choosing an Aluminium Finish

Why it matters on a project

Finish is usually treated as an appearance decision and priced as a rate. It is actually a durability decision that determines how the building looks in ten years, and it is close to impossible to correct once the facade is installed — recoating aluminium in situ never matches factory quality.

How they compare

	Anodising	Powder coating
Nature of finish	Oxide layer grown from the metal	Polymer film applied on top
Can it peel?	No — it is part of the substrate	Yes, if pre-treatment was poor
Colour range	Limited: silver, bronze, champagne, black	Effectively any RAL shade
Colour consistency	Batch variation is real and visible	Excellent, consistent between batches
Abrasion resistance	Very high	Moderate
UV / chalking	Does not chalk	Depends entirely on resin grade
Coastal performance	Strong	Strong with PVDF, weak with polyester
Typical relative cost	Higher	Lower to comparable at PVDF grade
Repair on site	Very difficult	Touch-up possible, rarely invisible

Common mistakes

• Accepting "powder coated" without naming the resin. Standard polyester and PVDF to AAMA 2605 are different products with very different lifespans. The specification must name the grade, not the process.
• Not batching anodised profiles. Anodised colour varies between production runs. Profiles for one elevation should come from one batch, and that has to be planned before ordering.
• Ignoring pre-treatment on powder coating. Adhesion is entirely dependent on chromate or chrome-free pre-treatment. Coating over poorly prepared aluminium fails at the edges within a few years.
• Choosing on rate alone. The cheaper finish that fades in five years costs vastly more than the difference, because correcting it means access equipment across a live building.
• Forgetting the fixings. Stainless fasteners against a coated surface, and dissimilar metals in contact, cause staining and galvanic problems that are blamed on the finish.

Where Hagerstone uses it

Both finishes run through our facade scope across curtain wall, doors and windows, cladding and architectural elements. Through Viva Composite Panel we work with ACP, solid aluminium, honeycomb, louvre and rainscreen products in 500+ shades with fire-retardant grades and PVDF coatings — the coating class worth specifying where colour has to hold outdoors.

Standards referenced

Anodic coating thickness and quality classes follow IS 1868. High-performance organic coatings — the PVDF class — are specified to AAMA 2605, which is the grade to name when weathering and colour retention matter.