Galvanized metal is a highly durable material, making it an ideal choice for several objects such as car bodies, bicycles, piping, playground equipment, etc. The only downside is that it doesn’t look aesthetically pleasing, but luckily, you can spray paint it to make it more attractive.
You can spray paint galvanized metal to increase its lifespan and improve its aesthetic appeal. However, spray painting directly on a galvanized surface will cause it to peel, so you should treat and prime the surface thoroughly before you start painting.
Spray painting on galvanized metal isn’t that simple, but if you follow the correct procedure, you can get flawless coverage without professional help at home. Let me share with you what I have learned through my experience of painting on galvanized metal.
What Are The Challenges Of Painting Galvanized Metal?
A question I get a lot is, ‘Can you spray paint zinc-plated steel?’ The reason many people feel don’t feel confident spray painting galvanized metal is that it doesn’t stick to the surface, and they end up wasting their time and energy.
Metal surfaces are coated with a thin layer of zinc to prevent rusting. That is why when you try painting zinc-plated steel directly, it reacts with the paint’s binding agents and causes the paint’s layer to crack and peel.
When you paint on a galvanized metal surface that has not been adequately prepped, the paint will have trouble adhering. Therefore, cleaning the surface and preparing it following the correct process will help you achieve lasting coverage.
Why Do You Need to Paint Galvanized Metal?
We know that galvanized metal surfaces are well-protected from short-term and long-term corrosion. This brings us to the question, ‘why do we need to paint a galvanized surface in the first place?’
The reason is that even though the material is highly durable, it is still vulnerable to environmental elements such as acidic rain, sulfur dioxide, and other reactive substances. Also, if the surface comes in regular contact with salty water, its corrosion rate would increase, reducing the lifespan of the metal.
Painting galvanized metal increases the surface’s longevity and enables it to withstand environmental stressors. In addition to providing supplementary protection, the paint helps the object look more aesthetically pleasing.
Which Paint Should You Use to Paint Galvanized Steel?
While preparing the surface properly is crucial, choosing the right spray paint that sticks to galvanized surfaces without cracking or peeling is equally important.
Alkyd or oil-based primers and paints aren’t a good fit because their chemical composition creates an unfavorable reaction with the zinc coating, resulting in the formation of a film on the surface.
This film prevents the paint from adhering to the metal as the paint dries, often leading to problems like chipping, flaking, bubbling, and peeling. Instead, you can buy oil-based and alkyd paints and primers specially designed for galvanized metal to avoid the mentioned issues.
A better option is to choose water-based primers or paints created for metals specifically. Water-based paint versions don’t react with the zinc coating or form a film on the surface, which means there will be no adhesion issues as you paint.
If you’re wondering, ‘will Rustoleum paint stick to galvanized metal?’ The answer is yes! The Rust-Oleum Galvanizing Compound is a great option for painting on galvanized surfaces. Apart from adhering well to galvanized surfaces, the paint dries to the touch within 20 minutes.
Equipment You Will Need To Paint Galvanized Metal
Here are a few supplies you will need to start your metal painting project:
- Chemical degreaser
- Vinegar/ Ammonia solution
- 240- grit sandpaper
- Primer for zinc-coated metal
- Spray paint for galvanized metal
- Lint-free tack cloths
How To Spray Paint On Galvanized Metal Surfaces
Painting on galvanized metal objects is a multi-step process, and if you follow every step carefully, you can get excellent coverage that lasts. So, if you want to know how to paint over zinc plating, here is a step-by-step guide to help you through the process.
Step 1- Clean and Degrease The Surface
Before you start cleaning, remember that our purpose is to clean the zinc coating thoroughly, not remove it.
A simple clean-up with hot soapy water will suffice if you work on a newly galvanized surface. You will follow a similar cleaning method if the surface is fully weathered. However, if the galvanized metal is partially weathered, you must remove the surface oxide, hydroxide film, and debris.
The best way to clean a galvanized surface is to use a chemical degreaser. The degreaser helps eliminate grease, grime, and other debris without affecting the zinc coating. Simply spray the solution over the surface and use a lint-free cloth to scrub it clean.
Step 2- Wipe With Vinegar
Galvanized metal isn’t an ideal surface for painting because it is difficult to make the paint stick. However, you can improve its adhesion by wiping it with a white vinegar solution. The acid in the vinegar reacts with the metal surface and provides a more agreeable surface to paint on.
You can also use an ammonia solution instead to prep the surface but only in well-ventilated areas. So, if you’re working on a project outdoors, an ammonia solution can work well to prep the surface for spray painting.
Step 3- Allow The Metal To Dry Completely
After wiping the surface with vinegar or ammonia solution, give it enough time to dry out completely. If you’re working on a roof, it might take a few hours, depending on the weather, but an indoor project would take less time.
Step 4- Begin Sanding
Take your 240-grit sandpaper and put it to good use by sanding the metal surface thoroughly. 240-grit sandpaper is ideal for galvanized metal because it can prepare the surface well without gouging the zinc coating.
You must be careful about how much pressure you apply while sanding. Keep a steady hand and try not to overdo it.
You can remove any attachments, like bolts, etc., at this stage so you can sand the entire surface properly. After you’re satisfied with the sanding results, wipe away any debris created during the process with a clean, dry cloth.
Step 5- Apply Primer
As discussed earlier, avoid using oil-based primers when painting galvanized metal. Instead, use one designed especially for painting on zinc-coated surfaces like the Rust-Oleum Flat Primer.
You should use a primer with a water-based formula that provides a solid base for excellent paint adhesion. If you are painting a surface for outdoor use, invest in a multi-purpose primer designed for outdoor use.
Allow your primer to dry completely before you move on to the next step. If the primed surface feels tacky to the touch, let it dry for longer because painting over wet primer is not recommended.
Step 6- Start Painting
The paint application of galvanized metal is pretty straightforward. Make sure to use spray paint that’s ideal for galvanized surfaces, and apply the paint in thin layers, allowing plenty of time between coats for the paint to dry.
Spray paint usually takes 10 to 20 minutes to become touch dry on galvanized surfaces, but it can take up to 24 hours to fully cure. Refer to the paint’s label to check the recommended time so you know how long you should wait between coats.
You can read how long it take the spray paint to dry on our website too.
Can You Paint Rusted Galvanized Metal?
It is possible to paint rusted galvanized metal, but it requires more prep work. If you don’t clean all the rust before painting, it will eventually spread and ruin the surface. Therefore, scrub off any rust with a wire brush or sandpaper first and then apply the primer.
Some spray paints are designed to stop rust from spreading and turn any existing rust into a non-rusting surface. However, you should sand the surface thoroughly, so you have a smooth base to paint on, regardless of the type of paint you use.
Will paint stick to zinc-plated metal?
Paint doesn’t stick to the zinc-plated metal if the surface hasn’t been prepped properly. Using a primer before you paint also helps the paint adhere to the metal.
Can stainless steel be zinc plated?
Stainless steel can be zinc plated, offering excellent corrosion protection and a smooth, clean finish.
What spray paint can I use on galvanized metal?
Cold-galvanizing spray paints work well on galvanized surfaces. You can also use acrylic latex paint or water-based paints formulated for zinc-coated metal.
Can you spray paint over rust on metal surfaces?
No, you cannot. If you want the spray paint to apply evenly and stick to the surface, you must clean the rust and sand the object before painting.
Hopefully, you now know the answer to ‘can you spray paint galvanized steel.’ If you use the correct primer and paint while following all the steps outlined above, you shouldn’t have any trouble painting on a galvanized metal surface.