Mild Steel and Aluminium Powder Coating Services
Specialist powder coating for mild steel and aluminium components, delivering durable, high-quality finishes for industrial, commercial and architectural applications across Harlow, Hertfordshire, Essex and London.
What Is the Difference Between Coating Mild Steel and Aluminium?
Mild steel and aluminium are the two most commonly powder coated metals in the UK, but they require fundamentally different preparation processes. Applying the same pre-treatment to both metals is one of the most common causes of premature coating failure — the powder may look identical on the surface, but the bond underneath is compromised from day one.
Mild steel is prone to rust and requires thorough degreasing, shot blasting and iron phosphate treatment to remove contaminants and create a corrosion-resistant base. Aluminium does not rust in the same way, but it forms a layer of aluminium oxide that must be removed and replaced with a chromate-free conversion coating to ensure proper adhesion.
We provide coating for:
- Mild steel structural components
- Aluminium architectural elements
- Fabricated parts and assemblies
- Balustrades, railings and staircases
- Gates, fencing and external metalwork
We coat both materials to the same standard — the difference is in the preparation, not the finish.
How Does Pre-Treatment Differ for Mild Steel and Aluminium?
Different materials require different preparation approaches to achieve the best results.
Mild Steel Coating
Mild steel corrodes quickly when exposed to moisture, so surface preparation is critical. Without proper treatment, rust can form beneath the coating within months — even if the powder itself is undamaged.
We ensure:
- Degreasing to remove oil, grease and handling marks
- Shot blasting to remove mill scale, rust and old coatings (Sa 2½ standard)
- Iron phosphate pre-treatment to create a corrosion-resistant conversion layer
- Coating within 4 hours of blasting to prevent flash rust
- Durable finishes rated for both internal and external use
Aluminium Coating
Aluminium does not rust, but it forms a thin oxide layer that prevents powder coating from bonding properly. This oxide must be removed and replaced with a controlled conversion coating.
We ensure:
- Alkaline cleaning to remove grease and surface contaminants
- Chromate-free conversion coating to promote adhesion and prevent under-film corrosion
- Non-ferrous abrasive media (aluminium oxide) when blasting is required — steel grit would embed iron particles that cause corrosion beneath the coating
- Smooth, even coating application suited to architectural and decorative finishes
- High-quality finishes for both internal and external applications
Which Industries Use Mild Steel and Aluminium Powder Coating?
Steel fabricators
Structural sections, beams, brackets and fabricated assemblies requiring durable, corrosion-resistant finishes for construction and infrastructure.
Construction contractors
Balustrades, staircases, handrails and site metalwork delivered coated to specification and programme for commercial and residential builds.
Architects and designers
Aluminium cladding, curtain walling, louvres and decorative metalwork finished to RAL specification with consistent colour across all components.
Manufacturing companies
Production components, enclosures, frames and assemblies coated in batch runs with reliable colour matching and repeatable quality across orders.
Our team understands the demands of industrial environments, including scale, consistency and reliability.
Why Choose Spraytech for Steel and Aluminium Coating?
Correct Preparation for Each Material
We apply the appropriate preparation process for mild steel and aluminium, ensuring strong adhesion and long-lasting performance.
Consistent Finish Across All Components
We deliver uniform colour and coating quality across all items, whether for one-off projects or batch production.
Durable, Long-Lasting Coatings
Our powder coating systems provide strong resistance to wear, corrosion and environmental exposure.
Suitable for Multiple Applications
We support industrial, commercial and architectural projects, adapting our coating system and preparation process to match the specification.
Reliable Turnaround Times
We provide 48-hour average turnaround on standard work, with scheduled production for larger programmes. Collection and delivery across London and the South East.
Our Coating Process for Steel and Aluminium
Inspection of components and material type
Surface preparation and pre-treatment
Powder coating application
Controlled curing process
Final inspection and quality checks
Each stage is tailored to the material and project requirements.
Applications We Support
We provide powder coating for:
Our flexible approach allows us to adapt to both one-off projects and long-term partnerships.
Mild Steel and Aluminium Coating Across Hertfordshire, Essex, London and the South East
Based in Bishop’s Stortford, we provide coating services across:
We are well positioned to work with powder coating projects throughout the UK
Get a Quote for Steel or Aluminium Coating
Send us your drawings, specifications or production requirements and we’ll provide a fast, competitive quote.
Mild Steel and Aluminium Powder Coating
What is industrial powder coating?
Industrial powder coating is a dry finishing process where polyester, epoxy or hybrid powder is applied electrostatically to metal components and cured in an oven at 180–200°C. The cured coating forms a hard, durable layer that protects the metal against corrosion, wear, UV damage and weathering. It is the standard finishing method for industrial components, structural steelwork and architectural metalwork across the UK
Can you handle large-scale industrial projects?
Yes. We operate six ovens across two facilities in Bishop’s Stortford, with up to 10 metres of oven capacity. This allows us to handle large structural sections, high-volume batch work and ongoing production contracts. Our experience includes architectural coating for Embassy Gardens in London and Stansted Airport terminal expansion.
What materials can you coat?
We coat mild steel, aluminium, galvanised steel, cast iron and stainless steel. Each material receives a specific pre-treatment process — mild steel is shot blasted and iron phosphate treated, while aluminium is alkaline cleaned and treated with a chromate-free conversion coating. This material-specific approach is essential for long-term adhesion and corrosion resistance.
Do you offer surface preparation?
Yes. Surface preparation is included as a standard part of our coating process. For mild steel, this includes degreasing, shot blasting to Sa 2½ standard and iron phosphate treatment. For aluminium, we provide alkaline cleaning and chromate-free conversion coating. We also use non-ferrous abrasive media when blasting aluminium to prevent iron contamination.
Do you support ongoing production work?
Yes. We support both one-off projects and ongoing production contracts. For batch manufacturing and repeat orders, we maintain strict colour control and quality processes so that components coated weeks or months apart are visually and structurally consistent. Contact us to discuss your production requirements.
