Anodising vs Powder Coating: Choosing an Aluminium Finish
Anodising grows a hard oxide layer out of the aluminium itself by electrolysis; powder coating sprays a polymer onto the surface and bakes it on. One is part of the metal, the other sits on top of it — which is why they age in completely different ways.
By Dhruv Agarwal · · 2 min read
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.
Standards referenced
Frequently asked
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