Zinc Spray

Zinc Spray for Metal Corrosion Protection

Zinc spray is an aerosol protective coating used primarily for corrosion protection of steel and galvanised steel, repair of damaged zinc layers and selected automotive or metal-repair applications.

High-zinc coatings can provide sacrificial cathodic protection to correctly prepared steel, while the binder forms the coating film on the surface.

The current range includes Dinitrol and C.A.R. Fit zinc sprays in 400 ml aerosols. Their formulations differ, so technical data such as zinc content and overcoating times should never be assumed to be identical across the category.

What Is Zinc Spray Used For?

• corrosion protection of bare steel,
• repair of damaged galvanised surfaces,
• protection of drilled and cut metal areas,
• weld and spot-weld areas where the product is approved,
• automotive body repairs exposing bare steel,
• general corrosion protection of suitable metal components.

Always follow the individual product specification for the exact approved application.

Cold Galvanising Spray

The term cold galvanising spray is commonly used for zinc-rich coatings that can be applied at ambient temperature.

This is not the same process as industrial hot-dip galvanising. Instead of immersing the component in molten zinc, the aerosol forms a zinc-containing protective coating on the prepared metal surface.

Dinitrol 443 High-Zinc Spray

Dinitrol 443 is a high-zinc corrosion-protection coating. According to the manufacturer, the product has 95% zinc content and provides strong adhesion to steel and galvanised steel.

It is intended for repairing damaged zinc layers, protecting drilled and welded areas, general metal corrosion protection and use as a conductive intermediate layer for spot welding.

The 95% figure is specific to this product and should not be applied to every zinc spray in the category.

Dinitrol 444 Zinc-Aluminium Spray

Dinitrol 444 uses zinc and aluminium pigments rather than the same formulation as Dinitrol 443.

The aluminium content helps produce an appearance closer to galvanised metal while the coating is intended to repair damaged zinc layers and provide corrosion protection.

It can also be used as a conductive intermediate layer for compatible spot-welding applications.

Zinc Spray for Welding

Selected zinc sprays can be used as weld-through or spot-welding primers where specifically approved by the manufacturer.

This does not mean every zinc aerosol is suitable for every welding process. Always confirm the product's approved use before welding.

Repairing Galvanised Steel

Grinding, drilling, cutting and welding can damage the original zinc coating on galvanised automotive steel.

A suitable zinc spray can form part of the repair process by restoring local corrosion protection before the remaining coating system is applied.

Zinc spray does not automatically replace every primer or refinishing layer required by the complete repair system.

Zinc Spray vs Rust Converter

Zinc spray is not a rust converter.

It is primarily intended for clean, stable and correctly prepared metal. Loose or active corrosion should be removed or treated correctly before the zinc coating is applied.

Surface Preparation

1. Remove corrosion and unstable old coatings.
2. Abrade the metal as specified for the product.
3. Remove dust and degrease thoroughly.
4. Allow the substrate to dry completely.
5. Shake the aerosol thoroughly to distribute the heavy metallic pigments.

How to Apply Zinc Spray

Spray distance, number of coats and flash-off times vary between products.

Use a correctly conditioned aerosol, shake it thoroughly, carry out a test spray and apply uniform coats according to the individual manufacturer's instructions.

Can Zinc Spray Be Overpainted?

Many zinc coatings can be overpainted, but the required waiting period and compatible coating system vary significantly.

Dinitrol 443, for example, is specified by the manufacturer as overpaintable after approximately 30–60 minutes with suitable systems, while the C.A.R. Fit product lists a considerably longer recoat time.

Always follow the technical data for the exact product rather than applying one general recoat rule.

Zinc Spray vs Conventional Primer

Zinc spray and a conventional automotive primer do not necessarily perform the same function.

Zinc coatings are primarily used to provide corrosion protection to suitable metal and restore damaged zinc layers, while epoxy, filler and other primers can provide different properties such as isolation, adhesion and surface levelling.

Safe Use

Zinc sprays are pressurised solvent-containing aerosols. Provide adequate ventilation and use the respiratory, eye and skin protection specified in the safety data sheet.

Keep aerosols away from flames and ignition sources. When used around welding operations, follow both the coating and welding safety requirements.

Frequently Asked Questions About Zinc Spray