Anodising
Service Overview
Astro Anodising offers superior anodising services to manufacturers using aluminium in the production of their end products. We supply a diverse range of customers across various industries, from architectural and building trades to automotive, signage, and general manufacturing.
We offer the largest selection of anodising colours and finishes available in South Africa, with the capability to handle work ranging from small parts and machined components up to lengths of 3.3m.
Extrusion Anodising
We anodise aluminium extrusions across a wide range of standard sections and custom profiles, in a full range of colours and finishes. Lengths up to 3.3m can be accommodated.
Sheet Anodising
We anodise aluminium sheet in natural finish and a range of colours, including full-size sheets of 3m x 1.5m in natural finish.
Astro Anodising Divisions
Semi-Architectural and Brightening Division
Our semi-architectural and brightening division handles work from 1m up to 3.3m in length, in a wide selection of colours available in either matt or bright finish. Full-size sheets (3m x 1.5m) are available in natural finish. Smaller sizes are available in specific colours.
Colours available: natural, brass, gold, champagne, gun metal blue, black, silver, purple, red, green, blue, pink, orange, bronze, bronze 541, bronze 542, bronze 543, bronze 545, and bronze (double dip process).
Please note: purple and green are only available for components under 1m x 1m in size.
For Architectural Applications
We offer anodising in natural finish and a selection of architectural colours, to thickness specifications of 15 or 25 microns. Natural anodising is recommended for coastal applications due to its superior corrosion resistance, durability, and low environmental impact, and is widely used as a pretreatment before powder coating or paint.
Component Division
We specialise in the anodising of aluminium components of various sizes and configurations. Purpose-designed titanium jigs are used to limit contact marks. Job-specific jigs can be manufactured for volume-based work.
Colours available: natural, brass, gold, champagne, gun metal blue, black, silver, purple, red, green, blue, pink, orange, and bronze.
Standard Colour Range
Our standard colour range includes natural, black, silver, brass, gold, blue, red, orange, green, champagne, bronze 1, bronze 2, bronze 3, bronze 541, bronze 542, bronze 543, and bronze 545.
Standard colours are available in either bright or matt options.
Green is only available for components 500mm x 500mm in size.
Special or custom colours are available on request. Please enquire directly with our team.
Value-Added Services
Chemical Brightening
A chemical pretreatment process that improves the reflectivity and brightness of the aluminium surface before anodising, producing a high-gloss finish suited to decorative and cosmetic applications.
Mechanical Polishing
We offer mechanical polishing as a pretreatment option for extrusions, producing a smooth, reflective surface before the anodising process is applied.
Mechanical Brushing
We offer mechanical brushing as a pretreatment option, producing a consistent, linear grain finish on the aluminium surface before anodising.
Specialised Jigging
For components where contact marks must be minimised or controlled, we offer specialised jigging solutions, including purpose-designed titanium jigs and job-specific jigs for high-volume production runs.
Aluminium 360° | Our Turnkey Approach
Anodising is one part of our Aluminium 360° offering. If your project requires aluminium sourcing and supply, fabrication, powder coating or surface preparation alongside this service, all are available in-house.
Frequently Asked Questions
What is the process of anodising?
Anodising is an electro-chemical process that increases the thickness and density of the natural oxide layer on the surface of aluminium. Unlike paint or plating, the anodised layer is integrated into the surface of the metal rather than applied on top of it, which means it cannot peel, flake, or crack under normal conditions.
The process takes its name from the role the component plays in the electrolytic circuit: the part to be treated forms the anode, which is immersed in an acid electrolyte bath and subjected to an electrical current. This builds up the oxide layer to a controlled thickness, measured in microns.
The result is a surface that is harder and more durable than untreated aluminium, resistant to corrosion and UV exposure, and available in a wide range of colours through the application of dyes during the anodising process.
What are the key properties of anodised aluminium?
- The anodised layer is part of the metal, not a coating applied on top of it
- Significantly harder and more adherent than most paints or platings
- Resistant to corrosion, UV exposure, and fading
- Available in a wide range of colours and finishes
- Increases component lifespan and range of use
- Recommended as a pretreatment before powder coating for coastal and high-exposure applications
What is the maximum length Astro Anodising can handle?
We can anodise work up to 3.3m in length across our semi-architectural and brightening division.
What is the difference between bright and matt anodising?
Bright anodising produces a reflective, high-gloss surface, while matt anodising produces a lower-sheen, diffused finish. Both are available across our standard colour range, with the exception of green, which is only available for components 500mm x 500mm in size.
Can Astro Anodising handle architectural anodising for coastal applications?
Yes. Natural anodising is recommended for coastal applications due to its superior corrosion resistance and durability. We offer architectural anodising to thickness specifications of 15 or 25 microns.
Can anodising be used as a pretreatment before powder coating?
Yes. Natural anodising is an effective pretreatment for powder-coated finishes and is widely recommended for applications requiring superior corrosion resistance. Where powder coating is required, this can be accommodated through Astro Powder Coating.
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