Technical Guidance

Life Expectancy

Powder coatings will weather in any environment and the rate of weathering depends on the conditions the coating is subjected to. The coating system's resistance to corrosion will depend on local conditions, the choice of material, and the preparation of substrate prior to powder coating. We give some guidance on how long your coating system will last in a number of different environments.

Marine Environment

All our exterior durable coatings are suitable for the marine environment, therefore choose the product based on the gloss and colour fastness you require - ultradurable polyesters will retain their gloss and colour longer than our high durable or standard durable systems. However, owing to high salinity and high humidity, the marine environment is a very aggressive one for corrosion. ISO 12944-2:1998 classifies these areas as 'C5M'.

Corrosion resistance will depend on the choice of metal substrate, its preparation, and the number of layers of powder coatings applied. Below are a selection of suggested coating systems with their expected lifetime. Please note that 'expected lifetime' is an indication of foreseen useful life, taken from the ISO 12944.  It is not a warranty or guarantee period.  Regular maintenance of coated materials will maximise durability

  • Mild Steel - Medium (5-15 years) Durability

    Chemical Preparation

    • Remove sharp edges
    • Iron phosphate with final rinse process
    • Polyester edge-covering technology 60-70 microns

    Physical Preparation

    • Remove oils
    • Remove sharp edges
    • Grit blast to a minimum cleanliness of Sa2.5 and a roughness of Rz = 40-60 microns
    • Epoxy Polyester NZP Primer 60-70 microns
    • Standard, high, or ultra-durable polyester topcoat 60-70 microns

  • Mild Steel - High (15+ years) Durability

    Physical Preparation

    • Remove oils
    • Remove sharp edges
    • Grit blast to a minimum cleanliness of Sa2.5 and a roughness of Rz = 40-60 microns
    • Epozinc 1000 Primer 60-70 microns
    • Eposeal Primer 60-70 microns
    • Standard, high, or ultra-durable polyester topcoat 60-70 microns

  • Hot Dip Galvanised Steel - High (15+ years) Durability

    Chemical Preparation

    • Linish sharp edges
    • Zinc Phosphate chemical process
    • Eposeal Primer 60-70 microns
    • Standard, high, or ultra-durable polyester topcoat 60-70 microns

    Physical Preparation

    • Linish sharp edges
    • Sweep blast with a non-ferrous medium
    • Eposeal Primer 60-70 microns
    • Standard, high, or ultra-durable polyester topcoat 60-70 microns

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