When looking at galvanized metal, you’ll probably have one or two reactions. You might think that the mottled metallic look is appealing, adding some texture while maintaining an industrial edge. The thing is, you might also find the uneven look atrocious. If you’re in the latter category, figuring out how to paint galvanized metal is usually a must.
Painting galvanized metal is a multi-step process. You’ll need to clean the surface using the right products, such as dish soap, white vinegar, or ammonia. After that, performing a light sanding and using the correct primer and paint is essential. Otherwise, you may end up with adhesion issues.
If you’re trying to figure out how to paint galvanized metal correctly, here’s a look at what you need to know, including a step-by-step process you can follow.
Can You Paint Galvanized Steel?
Yes, you can paint galvanized steel, but you need to use the right approach. Painting straight onto galvanized steel that isn’t properly prepped may not work well, as the paint might have trouble adhering. However, by cleaning the surface, prepping it correctly, and following the right application process, you can get solid, lasting coverage.
It’s also important to note that you need to use the correct paint. Generally speaking, alkyd and oil-based paints and primers won’t stick to galvanized metal. The chemical composition of those primers and paints creates an unfavorable reaction with the zinc on galvanized metal surfaces, essentially leading to a film.
Once the film forms, it prevents the paint from sticking to the metal properly as it dries. As a result, you get adhesion issues, leading to problems like bubbling, peeling, flaking, cracking, and chipping.
While there are oil-based and alkyd paints and primers designed specifically for galvanized metal, it’s usually best to go in an entirely different direction. By sticking with water-based paint and primer – including latex versions – you won’t end up with a film. As a result, your chances of adhesion issues go down significantly.
However, it is best to find water-based paints or primers meant for metal. While those that aren’t won’t have the same issues as oil-based or alkyd paints and primers, they aren’t necessarily designed with metal in mind. By choosing a direct-to-metal water-based paint or primer, you’ll know that you’re getting the best product for your specific project.
As for the application method, you can use any approach as long as it works with the paint or primer you select. Brushes, rollers, and sprayers can work well if you use the right technique, so go with the method that makes the most sense for your project or skill level.
When it comes to the number of coats, what you’ll need varies depending on the paint and primer. In most cases, two will do the trick. However, there are some one-coat products available, cutting the amount of work in half.
Can You Spray Paint Galvanized Metal?
Yes, you can spray paint galvanized metal. However, as mentioned above, you need to use spray paint designed for the job. There are versions designed to stick to galvanized metal specifically. By going with those, you may not need a primer.
If you want to use spray paint that isn’t intended for galvanized metal, you’ll need to use a primer before painting. That way, the underlying layer sticks correctly, creating an even, workable surface for the paint layer.
Additionally, you’ll want to do some surface prep before applying paint, including cleaning, sanding, and more. That way, the paint will stick properly.
As previously discussed, you’ll want to stick with water-based paint more often than not. Oil-based and alkyd paints generally won’t adhere properly, leading to peeling and chipping in the future. The only exceptions are alkyd or oil-based spray paints designed specifically for galvanized metal, as those were created specifically to work in this situation.
Can You Use Vinegar to Clean Galvanized Metal Before Painting?
Yes, you can use vinegar to clean galvanized metal before painting. Vinegar is excellent for preparing the surface of galvanized metal, allowing paint or primer to adhere better. Plus, it’s non-toxic, making it a safer choice, particularly if you’re working in an enclosed space.
Usually, you want to apply vinegar after cleaning the metal’s surface with dish soap and warm water mixture. Clean it using the mixture, then rinse with clean water. After that, apply a vinegar mixture to the metal’s surface to prep it further. Once dry, the metal will be ready for sanding and painting.
Generally speaking, you’ll want to use white vinegar. It’s an affordable version, and it doesn’t stain most materials. Just be careful with drips, as the acids in vinegar can break down certain floor finishes, leaving dull spots.
How to Paint Galvanized Metal
If you’re trying to figure out how to paint galvanized metal, the answer lies in the process. Painting galvanized metal does require some prep work. Otherwise, the paint might not stick as well as you’d like.
Fortunately, using the correct strategy, you can achieve exceptional paint adhesion, ensuring the metal underneath remains protected and you get the final look you’re after.
Here is a look at a step-by-step process for painting galvanized metal.
1. Clean the Surface
If your galvanized metal has been exposed to the elements or has sticker residue on it, you’ll want to clean the surface. Usually, you can start with some warm water and dish soap. Wipe the surface down using a soft rag or sponge to remove grime, then rinse with clean water.
If sticker residue isn’t coming off, you can use mineral spirits to tackle the adhesive. Use a clean rag and press the mineral spirits to the residue. Let it sit for a few minutes before wiping the glue away. Then, rinse and dry the surface.
2. Wipe with White Vinegar
Generally speaking, the surface of galvanized metal isn’t ideal for painting. However, by wiping it down with a white vinegar solution, it’ll be more agreeable. The acids in white vinegar react with the surface, leading to better paint adhesion.
Alternatively, you could use an ammonia solution. It’ll also prep the surface but isn’t ideal to use in spaces that aren’t well-ventilated. As a result, you’ll want to wear a breathing mask if you go this route.
In many cases, ammonia will be more practical if you’re trying to paint a galvanized roof. Plus, ventilation will be less of a challenge since it’s outdoors.
3. Let the Metal Dry
After you’ve wiped the metal down with a white vinegar (or ammonia) solution, you’ll need to let it dry. For a roof, this could take a few hours, depending on the weather. For metal stored indoors, it may take less time.
4. Sand the Surface
Sanding the surface of the metal also promotes paint adhesion. Additionally, if the metal has been exposed to the elements and is rusting, it gives you a chance to address that issue before painting.
Usually, you’ll want to use 240-grit sandpaper. It’s rough enough to prepare the surface well but fine enough to avoid gouging the surface. Just make sure to apply steady pressure and not overdo it. Additionally, you’ll need to take extra care when addressing crevices or corners.
If you’re dealing with an installed metal roof, you may need to remove attachments or other items that block areas you need to sand. That way, you can do an even job.
Once you’re done sanding, take a clean, dry cloth and wipe the surface down. That way, you remove any debris created by the sanding process.
5. Apply Primer
Depending on the type of paint you’re using and the state of the starting surface, you may need to apply a primer. If so, make sure you aren’t using an oil-based primer, as that doesn’t work well with galvanized metal. Otherwise, apply one or two coats following the manufacturer’s directions and let it dry completely before moving on to painting.
6. Paint the Surface
After the primer is dry (if you need to apply it), you can paint. Use the appropriate tool based on the paint type and follow the manufacturer’s directions regarding the thickness of a layer and the number of coats. Then, let it dry.
How to Paint Galvanized Pipe
If you’re wondering how to paint a galvanized pipe, the process is mainly the same as what you see above. The main difference involves handling loose pipes, as getting full coverage creates challenges.
Painting galvanized pipe that isn’t yet installed can be tricky, mainly because the pieces themselves are a bit unwieldy. However, it can still be done.
For pipes that are in place, the process is a bit easier. The installation provides support and often makes accessing all sides of the pipe an option. The only exception is with close-quarters installations, where smaller brushes and patience are potentially a necessity to get the job done right.
Here’s a look at how to paint galvanized pipes.
1. Clean the Surface
Before you start painting, you’ll need to prep the surface. Start by washing the surface with a dish soap and water mixture, removing any dirt and grime. Mineral spirits will usually handle it if you’re struggling with sticker adhesive.
2. Prep the Pipe
Before you start painting, you’ll need to do a little more prep work. You can wipe the surface down with a white vinegar or ammonia solution to promote better paint adhesion. A trisodium phosphate (TSP) cleaner could also work. Follow the manufacturer’s directions in regards to washing or soaking the pieces.
Once the prep is done, rinse the pipes and let them dry.
3. Sand the Pipes
As with the process above, light sanding might be wise if you want to ensure paint adhesion. Additionally, if you’re dealing with older pipes that have some rust, sanding will be a necessity.
Use 240-grit sandpaper over the surface, paying special attention to any areas with rust. Then, wipe the pipe down with a soft cloth to remove debris.
4. Get the Pipes in Position
If you’re painting pipes that aren’t installed, you may want to position them in a way that makes painting the entire surface easier. One option is to string up the pipes on a clothesline. By running the line through the pipe, you can hang the pipes horizontally, allowing access to the entire surface.
5. Apply Primer
The paint you choose and the surface condition ultimately dictate whether you need primer. If so, follow the manufacturer’s directions, applying one or two coats as instructed. Then, let it completely dry before moving forward.
Once the primer is dry (if it’s needed), you can paint. Apply an even coat based on the manufacturer’s recommendation. Then, if it isn’t a one-coat paint, apply a second to ensure full coverage. Once it’s dry, you’re done.
Can You Paint Rusted Galvanized Metal?
You can paint rusted galvanized metal, but you’ll need to do more prep work before you begin. If you don’t remove all of the rust, it may spread even if you apply a coat of paint over the top. To prevent that from happening, you’ll need to remove all of the rust with a wire brush or sandpaper first. Then, you can follow the process above.
The only exception is using a paint designed specifically to halt rust spread. There are several on the market, including options like Rust-Oleum Stops Rust Rust Reformer. With those, the paint stops the rust from spreading, essentially turning any existing rust into a non-rusting surface. Just keep in mind that you may still want to sand before you paint, ensuring you’re working with as smooth a starting surface as possible.
What Is the Best Paint for Galvanized Metal?
If you’re trying to figure out how to paint galvanized metal, the paint you choose does matter. Not all paints are designed to work well directly on galvanized metal, so you’ll need to use a version that offers exceptional adhesion.
Here are a few options worth considering.
Best Primer for Galvanized Metal
Generally speaking, the ZRC 10001 Cold Galvanizing Compound is the best primer for galvanized metal. One of the main reasons is that it’s designed to protect the underlying metal from corrosion and rust, ensuring the piece remains in good shape long-term. However, that isn’t the only benefit.
ZRC 10001 Cold Galvanizing Compound is also simple to apply. You can use a brush, sprayer, or roller, allowing you to coat a piece using your preferred method. Plus, the result is a gray color with a flat finish, making it a neutral backdrop for another color if you’d prefer to paint over it.
If you were trying to figure out how to paint galvanized metal, you should have a reasonably solid idea after reviewing the information above. As long as you use the correct paint and process, you shouldn’t have any issue getting the job done.
Did you learn everything you wanted to know about how to paint galvanized metal? If so, let us know in the comments section below. If you know anyone else who would find the information above useful, please feel free to share the article with them.