1. Select oil-based or acrylic paints:

Acrylic Paints: Acrylic paints are adaptable, robust, and swiftly dry. They provide good rust resistance and stick to galvanized metal efficiently.
Oil-based Paints: Oil-based paints offer strong corrosion protection and are perfect for outdoor or high-traffic areas.
2. Search for Galvanized Metal Primer:

"It is essential to prime galvanized metal before searching what type of paint to use on galvanized steel. It improves adhesion and inhibits flaking or peeling.

3. Select Rust-Resistant Paints:

Metal surfaces are protected by coatings that are designed to prevent corrosion or rust. They're very helpful for long-lasting effects. This type of paint for galvanized metal is worth it.

4. Completely prepare the surface:

Preparation is essential. For better paint adherence, clean the metal surface, remove any rust that may be present, and lightly sand it.

5. Use Several Coats:

For best coverage and protection, paint should be applied in at least two coats. Before applying the subsequent coat, let the previous one completely dry."

@0707
Really helpful and clear. I note it down.
Thanks a lot.

Does the applicable galvanising standard permit the use of a non zinc containing repair option?

https://galvanizing.org.uk/welding-galvanized-stee....

https://www.astm.org/a0780_a0780m-20.html

Steve Jones
Corrosion Management Consultant

www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

Hi

Hot dip galvanized is a process of putting zinc on top of steel, to protect it from elements.
when the steel is expose back by a scratch the steel is not protected anymore and could rust.
to repair it or do a touch up, Zinc coatings are the best, following the ASTM A780

To answer your question, yes a 100% acrylic paint will have an "good" adhesion on Hot dip,but without anticorrosion in it you will introduce water a source for rust development.
never put alkyd paint over galvanized, you will have saponification and peeling.

So yes it's will adhere but the longevity will be short and you could see rust issue even with latex paint

Hope that help

Francois
Galvatech2000.com

Painting galvanized has similar issues to painting aluminum. The surface oxidizes quickly in air. The coating, with even the thinnest layer of oxides on the surface, is subject to hydration. Silanes are used on modern coatings systems to reduce hydration for coatings applied over oxidized surfaces. Zinc rich coatings often have silanes in there formulation from my understanding.

In general, acrylic resins seem to be the most tolerant of poor surface conditions. Regardless, you may consider a media blast or acid wash immediately before coating application.

Aluminum can be surface treated so that the oxide layer is an excellent substrate for adhesion (aircraft). Zinc oxide is a porous white powder that interferes with adhesion, and can chemically react with some paint chemistries in a not good way. Zinc rich coatings do not work galvanically as they are non-conductive so they are not directly comparable to galvanizing. Zinc particles are chemically reactive and will neutralize many corrosive materials that may permeate through the coating before they corrode the substrate.