Galvanized steel is everywhere in both industrial and residential spaces — staircases, railings, garage doors, sheds, fences, and building features like drip edges. The galvanizing process adds a layer of zinc to the metal that prevents corrosion. It’s certainly a durable material, but one that can’t be painted with typical products due to its smooth, non-porous surface.
Read on for our step-by-step guide (product recommendations included) for prepping and painting galvanized metal.
Step #1: Properly Prepare the Surface
Surface preparation is a key stage when painting galvanized surfaces, which are smooth and subject to many different contaminants from exposure to the elements. Whether the galvanized steel is new or weathered, remember that the entire surface needs to be clean, dry, and dull before you can successfully apply primer and paint.
Remove Rust and Flaking Paint
Weathered metal surfaces may have rust or flaking paint from a previous coating. Use an abrasive tool such as a wire brush or a sander to take off rust or old paint. You can also dissolve rust with white vinegar, and remove old paint coatings using vinegar or acetone. If needed, apply a chemical stripper.
For heavily rusted areas, use a product like Rust-Oleum Rust Reformer which will properly prep the surface for a longer-lasting coating.
Exposure to moisture can form a white, powdery substance on the surface of galvanized metal, called “white rust.” Use white vinegar and a wire brush to remove white rust before painting.
Clean and Degrease
Clean off dirt, grease, and other contaminants using white vinegar, acetone, rubbing alcohol, or detergent. These household items make for effective degreasers that also dry quickly. An added benefit of white vinegar is that it will etch the galvanized surface and improve paint adhesion.
Etch the Metal
Etching the metal is an important step, as it allows the primer and paint to adhere properly. To create the right surface texture, you can run over the surface of the metal with a scuffing pad or steel wool, gently sand it with fine-grit sandpaper, or even wipe it down with white vinegar.
Step #2: Prime for Maximum Adhesion
Apply an acrylic bonding primer before painting a galvanized metal surface. Never use an oil-based primer on galvanized steel or it will cause a chemical reaction with the zinc coating and the coating will not adhere properly.
Our paint experts highly recommend INSL-X STIX Waterborne Bonding Primer for galvanized metal or metal that was previously coated with a glossy finish. This acrylic-urethane primer and sealer adheres extremely well to glossy, hard-to-coat surfaces.
Best Primer for Galvanized Metal: INSL-X STIX Waterborne Bonding Primer
Formula: Acrylic
Recommended because: excellent adhesion on difficult surfaces
If the metal is already painted, is in good condition, and does not have a very shiny sheen, you can skip priming and recoat with any good-quality acrylic paint. Benjamin Moore Command is a great option for a durable acrylic paint that is easy to recoat and has a fast turnaround time.
Step #3: Apply the Right Metal Paint
Even though steel is a ferrous metal, galvanized steel should be treated as a non-ferrous metal when you choose the appropriate primer and paint. Always double-check if your chosen product is formulated for use on galvanized metals.
It’s very important to use an acrylic latex paint product on galvanized steel. Do not apply an oil-based paint or alkyd-based paint to galvanized metal. These products will cause a chemical reaction with the zinc oxide called saponification, creating a soapy film between the metal surface and the paint coating which will peel.
You’ll also want to choose a direct-to-metal paint formulated to resist corrosion. We recommend Benjamin Moore Ultra Spec HP D.T.M. for its long-lasting color retention and excellent adhesion to metal surfaces. Find technical information on Ultra Spec DTM in these data sheets: Low Lustre, Semi-Gloss, Gloss.
Best Paint for Galvanized Steel: Benjamin Moore Ultra Spec HP D.T.M
Formula: Acrylic Latex
Finishes: Low Lustre, Semi Gloss, Gloss
Recommended because: superior color retention, adhesion, and rust-inhibiting properties
Number of Coats & Dry Time
Apply 1-2 topcoats of Ultra Spec DTM in addition to your coat of primer. While Ultra Spec is a paint-and-primer, we recommend still using a waterborne bonding primer like INSL-X STIX for maximum adhesion.
Ultra Spec DTM has a dry time of four hours between applications and one hour between touch-ups. Keep in mind that dry times increase during humid weather or cool temperatures.
Paint Applicator Options
The best paint applicator for galvanized steel depends on the surface features and the project size. Spray paint for a quick, effective application for large projects and/or surfaces with hard-to-reach places. Roll paint to cover flat surfaces with a thick, even coat, and use a paint brush for the most control.
Paint Sprayer
Ultra Spec HP DTM can be applied with an airless sprayer. The fluid pressure should be set to 1,500-2,500 PSI, with a .013-.017 orifice. Follow the manufacturer guidelines on how far to hold the sprayer away from the painted object — usually around 12 inches — and maintain sprayer movement to minimize drips and achieve an even coat of paint. Spraying paint tends to result in thinner coats, so you may need to go over the surface multiple times.
Paint Roller
A paint roller and/or paintbrush will provide the thickest, most even coat on larger surface areas such as metal garage doors. Use a standard roller (9”) with a short nap (3/16” - 3/8"). For smaller areas, use a 4” mini roller. Only use synthetic fibers when applying acrylic paints like Benjamin Moore Ultra Spec DTM.
Paint Brush
Apply Benjamin Moore Ultra Spec with an all-purpose synthetic brush. Synthetic brushes are designed to perform well with acrylic, water-based paints that would damage a natural brush. Nylon/polyester brushes are also better on rough metal surfaces since they don’t break as easily as natural bristles.
Shop Galvanized Metal Paint at Ring’s End
We’re confident you’ll get great quality results painting galvanized steel with Benjamin Moore Ultra Spec HP D.T.M. This premium metal paint stands up to weathering and comes in three sheens and over 3,500 colors to meet a wide range of project needs.
Find this product and all the tools you need at Ring’s End! We carry a large selection of Benjamin Moore products in-store and ship Benjamin Moore paints anywhere in the U.S. Feel free to chat with one of our paint experts for additional guidance and product recommendations for your project. We’ll be happy to help!
Best Paint for Galvanized Metal: Benjamin Moore Ultra Spec HP D.T.M
Formula: Acrylic Latex
Finishes: Low Lustre, Semi Gloss, Gloss
Recommended because: superior color retention, adhesion, and rust-inhibiting properties