How to Paint Galvanized Metal

By: HowStuffWorks.com Contributors  | 

Galvanized metal is difficult to paint because it's coated with a layer of oil to prevent white rust. Alkyd and oil-based paints may seem to stick at first, but the oily layer eventually "sheds" the paint. Beside this, the zinc content of the galvanized coating reacts with paint's binder to create a film that causes the paint to peel [source: Sherwin-Williams]. Therefore, it's important to follow the correct procedure when painting galvanized metal.

Here's what you'll need to paint galvanized metal so that the paint won't peel off [source: Do It Yourself]:

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  • Ammonia
  • Heavy duty sandpaper, 240 girt
  • Metal primer
  • Metal paint, preferably the same brand as the primer. Look for a brand specially designed for galvanized metal.
  • Tack cloths

Here's how to paint galvanized metal:

  1. Wash the metal thoroughly with hot soapy water.
  2. Rinse the metal and let it dry completely for several hours.
  3. Rinse the metal with a weak solution of water and ammonia and allow it to dry.
  4. Remove any handles or other attachments from the metal.
  5. Sand the entire metal surface thoroughly, including crevices and dents.
  6. Wipe the entire surface with the tack cloths.
  7. Apply the primer as directed, covering the entire surface of the metal. It's best to start at the top and work down, section by section.
  8. Wipe off any drips that appear as soon as possible.
  9. Let the primer dry according to the directions.
  10. Inspect the surface carefully to make sure it's completely coated with primer.
  11. Read the directions on the container of metal paint.
  12. Apply the metal paint -- which should be the same brand as the primer -- according to the product directions.
  13. Let the paint dry according to the directions.
  14. Inspect the surface carefully to make sure it's completely coated with the paint [source: Do It Yourself].

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Originally Published: May 19, 2011

Paint Galvanized Metal FAQ

What paint will stick to galvanized metal?
Once the galvanized metal is cleaned thoroughly, most acrylic paints will adhere to it without any issues. For best results, it’s advised that you remove the layer of white rust that develops on weathered galvanized metal over time.
What is the best primer for galvanized metal?
Use a rust-preventing primer for improved corrosion resistance and to ensure the paint adheres to the metal. There are a number of options, but many people like Rust-Oleum Galvinoleum Primer, which comes in a spray can for easy application.
Do you need to prime galvanized metal before painting?
A primer is necessary before painting galvanized metal to ensure it adheres properly and dries more quickly.
Can you paint straight onto galvanised steel?
The short answer is no. Applying paint directly to galvanized steel will result in it peeling off. This is because the layer of zinc on the surface of the metal after the galvanization process isn’t compatible.
Does galvanized paint work?
Galvanized paint is a popular zinc-based paint that protects metal surfaces from rust and corrosion. Both cold galvanizing paint and hot-dip galvanizing paint can be used, but the latter is the preferred choice for professionals.

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