Duplex systems
Painting Galvanized Steel
Fully adherent coatings that do not peel on galvanized steel: sweep blasting, special adhesion primers and duplex systems.
Why does paint peel from galvanizing?
Hot-dip galvanized surfaces are smooth, and the zinc salts that form over time make it hard for paint to adhere. Coatings applied directly can therefore blister and peel within a short time.
On galvanized sheets and structures we roughen the surface with low-pressure sweep blasting without removing the zinc layer, then apply a special adhesion primer and compatible epoxy / polyurethane coating systems.
Duplex systems: double protection
Duplex systems combining galvanizing with paint last far longer in corrosive environments than either galvanizing or paint alone.
Applications
- Galvanized sections, sheets and steel structures
- Galvanized industrial components and poles
- Solar (PV) plant steel structures
- Electricity and lighting poles in public projects
Process
- Surface inspection: Zinc thickness and contamination are checked.
- Sweep blasting: Low-pressure roughening without removing the zinc.
- Adhesion primer: Special primer compatible with galvanizing.
- Topcoats: Epoxy intermediate and polyurethane topcoat; reported with DFT measurements.
Frequently asked questions
About painting galvanized steel
Does paint adhere to galvanized steel?
Yes, with the right surface preparation and primer. Because galvanized surfaces are smooth and chemically different, paint applied directly can peel. We roughen the surface with low-pressure sweep blasting and apply a special adhesion primer.
What is sweep blasting?
Sweep blasting is low-pressure precision blasting that lightly roughens the galvanized surface without removing the zinc coating, giving the paint a mechanical key.
What is a duplex system?
A duplex system combines hot-dip galvanizing with a paint system on top. The two protections complement each other and give a very long service life in corrosive environments. We apply it with galvanizing-compatible epoxy primer and polyurethane topcoat.
Request a quote for your galvanized parts
Send us your specification, part dimensions, tonnage and required coating system; our technical team will get back to you shortly.