DEMO — fictional range. Local brief only, NOT SENT. No personal data is collected or transmitted.
FINISH
On a solar array the finish is the corrosion protection.
A mounting system is expected to last as long as the modules, which is decades. The finish is what makes that possible, and it is specified for the atmosphere rather than for the appearance.
- Mill finish
- Extruded aluminium left as extruded · weathers to a dull grey, adequate inland
- Anodised
- An oxide layer grown from the metal · does not chip, thickness is the specification
- Powder coated
- A film over the metal · coloured, and a scratch is a starting point for corrosion
- Galvanised
- Steel dipped in zinc · thick and durable, but heavy and dull
- Sheradised
- Zinc applied by diffusion · for small parts, uniform and thin
- Stainless, bare
- No coating · the alloy is the protection, and the grade decides how much
Illustrative finish reference
| Finish | Typical use | How it fails |
|---|---|---|
| Mill finish | Inland rails | Surface staining, then pitting near the coast |
| Anodised | Frames and clamps | Thin anodising wears at contact points |
| Powder coat | Visible steelwork | A scratch lets rust spread under the film |
| Galvanised | Ground structures | Coating consumed over decades, then steel |
Why anodising thickness is the number.
Because anodising is not a coating that can be made thicker later. A thin layer is a short life, and the specification is a micron figure rather than a colour.
The one worth avoiding.
Powder coating a part that will be clamped and adjusted. The film is damaged at exactly the points that carry the load, and the damage is hidden under the clamp.