How do I paint galvanised or new metal so paint sticks?

New galvanised metal often has a smooth coating from the factory, and sometimes an oily residue as well. That means paint has very little to grip onto unless you prepare it properly.

First, wash the metal with a good detergent and plenty of clean water to remove dirt, dust, grease and salt. On exterior work in Auckland, this step matters even more because airborne salt and grime can affect adhesion.

Once the surface is clean and dry, lightly abrade it to create a key for the primer. For many jobs, a light sand with a fine abrasive pad or sandpaper is enough. You are not trying to remove the galvanising, just dull the surface so the coating can bond.

If the metal is already weathered or has light rust starting, remove loose corrosion completely before priming. Bare, clean metal is always better than painting over unstable material.

This is the step that makes or breaks the job. Standard wall primer is not suitable for galvanised or new metal. You need a primer designed for metal, and ideally one that suits galvanised surfaces specifically.

For new galvanised metal, a specialist galvanised metal primer or adhesion primer is usually the safest choice. On bare steel or iron, a corrosion-inhibiting metal primer is often more appropriate. Always check the product label to make sure it is compatible with the surface you have.

Apply the primer in thin, even coats rather than trying to build too much film too quickly. Heavy coats can trap solvent or moisture and reduce long-term adhesion.

If you are painting exterior metal, make sure the primer is fully cured before topcoating. Rushing this stage can lead to failure later.

Once primed, the topcoat should be a quality exterior paint system suited to metal. In many cases, an acrylic enamel or specialist exterior metal paint will be the right call, depending on the location and level of wear.

For handrails, gates, flashings and other high-touch or high-exposure areas, durability matters. A finish that resists moisture, UV and regular cleaning will generally last better than a basic decorative paint.

Make sure the primer and topcoat are compatible. Mixing incompatible products is a common reason paint lifts, wrinkles or loses adhesion early.

If you are painting in a coastal part of Auckland, such as Devonport, Mission Bay or St Marys Bay, extra care with preparation and product selection is worth it because salt air is hard on coatings.

If you are unsure whether the metal is galvanised, rusty, previously painted or coated with an unknown product, it is worth getting advice before you start. Steve is a Kiwi and a trade-qualified painter, and he can assess the surface, recommend the right prep and choose a coating system that is more likely to last.

That is especially helpful on larger exterior jobs, tricky architectural metalwork, or premium homes where a neat finish matters. Steve can also spot problems like contamination, poor previous coatings or moisture issues that are easy to miss until the paint starts failing.

If you want the job done properly the first time, contact Steve for advice or a quote. He is a Kiwi and a trade-qualified painter, and he works with Auckland homeowners and property managers who want a durable, professional result.