Painting foam board is one of the easiest ways to hide its white outer layers and improve its appearance.
However, it might not always be clear what paint to use. For many people, spray paint seems ideal, but does it really work?
Unlike regular paint, spray paint doesn’t leak streaks on foam boards. However, some brands contain solvents that can melt down the inner foam in the board.
In this article, we’ll answer these disturbing questions, can you spray paint foam board, what type of paint to use, and how to go about it without ruining the material?
Can You Use Spray Paint on Foam Board?
Yes, you can spray paint foam board if you use the right type of paint. Specifically, you should use water-based acrylic or specialty spray paints designed for foam boards. Avoid using oil paints as they contain solvents that can melt down the foam.
What is a Foam Board?
Foam board is a lightweight material with an inner layer of polystyrene foam. It’s a versatile product commonly used by students and craft enthusiasts for many practical purposes. Because of its adaptability, architects also employ it to create miniature models of their designs.
A foam board can be compared to cardboard. Cardboard is basically two light sheets of paper attached to a stronger middle layer, making something that is both strong and light. A foam board is very similar; it’s two sheets of paper or plastic sandwiched into a foam layer.
The foam is the polystyrene material we mentioned earlier. The three layers can be easily cut into different parts and shapes with a hobby knife, depending on what it’s being used for. Make sure the blade is nice and sharp.
Foam boards are available in different colors and sizes, but the standard options are white and a size 20″ by 30″ with 5mm thickness. You can easily find the boards in craft stores.
The two most popular uses of foam boards are signage and picture framing (backing). Others include mounting prints, costumes and props, backdrops, and even insulation. In fact, the only limitation is in your imagination and creativity.
Because foam board is typically sold with white outer layers, painting is often necessary.
Why Spray Paint Foam Board
There are many reasons to spray paint foam boards from artistic to structural. But in general, painting your foam board is a nice way to improve its appearance, especially when you want something other than white.
This can come in handy when you want to add color to a room without having to rely on wallpapers or other decorative elements.
In addition, compared to traditional painting methods such as brush painting, spray paint does not leave streaks on your project. It is also available in many colors and quantities.
It’s worth mentioning that when painting directly on foam board, whether with spray paint or a brush, avoid applying too much paint. Too much paint can saturate the outer paper layer, causing the edges to curl up and separate from the foam interior as the paint dries. This situation is commonly known as warping.
What Kind of Paint Can You Use on a Foam Board
Depending on the nature of your project, you can use different kinds of paint on foam boards. But the best option is acrylic.
You can use any water-based acrylic paint or special spray paint designed for specific foam boards. Many model crafts spray paints are acrylic or latex based.
The main advantage of using acrylic on foam boards is that it adheres well to the surface without soaking in too deeply. This way, it doesn’t melt the foam. Combined with a good primer, it can provide a good barrier against moisture.
Acrylic is also fast-drying and provides good coverage. It holds up well on foam board and leaves an even sheen.
Besides acrylic paints, you can also use poster paint or tempera, especially when working on children’s projects. Some latex paints or specialty sprays can also work but be sure they are safe for foam board.
Avoid using regular spray paint as they contain solvents that can dissolve the foam material.
Regardless of the paint you choose, test it on a spare board or a small inconspicuous area before proceeding with the project. Also, use thin layers of paint to prevent warping.
How To Spray Paint Foam Board
Spray painting foam board is relatively easy. All you need are the right tools and information.
What You Need:
Foam insulation board
Blade or sharp knife
Safety gear (mask and gloves)
Prepare Your Workspace
As with any other paint job, spraying foam boards requires adequate preparation to ensure you get the expected results.
Prepare the workspace by covering any item or surface you don’t want to get stained with paint. You can use a rag, some old sheets of newspaper, or masking tape.
Keep the windows open to ensure adequate ventilation in the room. You can take the project outdoors if it’s not windy outside.
Be sure to wear your gloves and a face mask.
Cut the Board
Get the foam board ready for priming. But before then, if it’s not the exact size you want, you can cut it into your preferred size using a blade or sharp knife. Before you cut, use a tape measure and pencil to get the correct measurements.
Then layer the board on a surface you don’t bother disfiguring with knife cuts. Measure out the spots to be cut, then use a felt marker to draw the line. Make the cuts along the line using a knife or blade.
Prime the Surface
Next, apply a good primer to provide a textured coat for the paint to adhere well. Our top recommendation is Gesso Universal Primer. This formula also provides water protection.
To apply the primer, you will need a flat paintbrush. Dip it into the primer and apply it on the foam board. You can apply multiple thin coats (we recommend two or three) with each coat in the opposite direction.
Allow each coat to dry completely before applying another one. Once the primer dries, proceed to the next step.
Sand the Surface (Optional)
If you used a primer, sanding might not be necessary since the primer already provides a rough surface for the paint to stick to. However, if you don’t like the existing texture and would like to smoothen it a bit, lightly sand it.
You will need 500 grit-sandpaper for this step. Try not to scrub too hard to avoid damaging the board.
Now, you’re ready to start painting. Shake the aerosol can thoroughly to mix the liquid and pigments well. Then hold it 10 to 12 inches away from the board. Begin spraying lightly in a circular motion across the board.
Avoid spraying any section of the board more than twice or bring the nozzle too close, as this can cause pooling, which may result in warping.
After the first coat, wait for it to dry before applying another coat. Drying times will be different for each brand. So, check the label to be sure.
Can You Spray Paint Poster Board?
Yes, you can. Poster boards serve as a great artistic base for spray paint, especially when you wish to create transportable art. Both kids and adults can use it for various crafts and artwork.
It is lightweight, easy to work on, and dries quickly when you use the right paint.
With spray paint, the fluid will not seep deeply into the base if you use a poster board with glossy sides.
Make sure there’s enough ventilation in the area you’re working in. It’s best to spray outside because of the toxic fumes. Also, cover your surrounding with a newspaper or cardboard.
If you’re looking for where to get a poster board, you can check any nearby craft store or supermarket.
Can You Spray Paint Foam Board Insulation?
Yes, you can paint spray foam insulation. Painting foam insulation is a good way to protect it from moisture and sunlight. The same applies to foam core boards.
When exposed to harsh weather, foam insulation boards tend to degrade over time, so painting it ensures it lasts longer, especially if the board is installed in a moisture-prone area. It will keep mold from growing on the surface.
In addition, painting also helps with aesthetics. It’s a nice way to give the board a facelift.
When painting, it’s recommended to follow the manufacturer’s instructions. Of course, that is after you must have chosen the correct type of spray paint. Ensure the surface is clean and debris-free, and always wear your safety gear when handling any spray paint.
Can You Paint on Black Foam Board?
Black foam board is another color option besides regular white, which means it can be painted. However, there are a few things you should keep in mind.
First, like the white foam board, black foam board will melt if you paint it with the wrong type. To be safe, you should use water-based acrylic or latex paint. These are fast-drying and adhere well to foam board, especially when used with a primer.
How to Paint Foam Board Without it Warping
One way to prevent warping while painting foam boards is to prime the surface beforehand. This helps to stop the paint from soaking up in the surface, which could cause color distortion, warping, or even peeling.
Another thing that could cause warping is applying the paint too thickly. It’s better to use multiple thin coats instead of one heavy coat.
Applying too much paint will cause the outer layer of the foam to become saturated as the paint dries. This makes the paper shrink while the foam inside doesn’t. When this happens, you will see the edges of the paper curling and warping.
So, whether you’re using spray paint or a brush, use thin coats. The lighter the coating, the better for you.
Make sure you allow the paint to dry completely between coats. Depending on the quantity of the paint and size of the foam board, you can use 2-3 coats or more. The goal is to get complete coverage of the board.
To paint foam board without warping, follow the steps below:
Prepare the board by cleaning the surface to remove dirt and debris. You can use a damp cloth for this purpose.
This step is optional. You can sand the surface to prepare it for priming.
Next, apply a primer. This will roughen the surface a bit and help the paint adhere better.
Allow the primer to dry, then paint evenly. Allow the paint to dry completely between coats. You can apply as many coats as you want until you get full coverage. Let the painted foam board cure fully before handling it.
Do You Need to Prime Foam Before Painting?
You don’t need to prime the foam board before painting. But, I highly recommend doing so as it helps in paint adherence and smoothing out the texture, which results in a longer-lasting result.
Priming also helps to prevent warping. Depending on the type of board, it could soak up paint if you skip primer and form less vibrant colors or peel off after some time.
I highly recommend using Gesso as your preferred primer. Besides helping the paint adhere better, it also provides water protection.
What To Look for In the Best Paint for Foam Board
There are a few factors to consider when choosing paint for foam boards. These include:
Type of Paint
This is probably the most important thing to consider when buying foam board spray paint. There are different types of spray paints, and not all are compatible with foam boards.
Look for acrylic or water-based latex paint. Oil paints contain solvents that can melt the foam. Whatever paint you choose, ensure the surface is clean and debris-free before you commence the project. Also, allow the paint to dry completely between coats.
Durability & Pigment
Durability has to do with the endurance of the paint job, while pigment refers to the paint color. Again, acrylic paints are usually more durable than other paint types for foam boards. Tempera paints also last but not as long as acrylic.
For the pigment, more is desirable. High-quality spray paints (like the ones highlighted below) usually have more pigments and turn out more vibrant as they dry.
Going for products with low VOCs is generally recommended when working with spray paint. This is because such products produce lesser fumes, making them safer.
Water-based spray paints such as acrylic are generally less toxic, and that is because they contain low VOC. As a result, they don’t have a very strong odor like their oil-based counterparts. Despite this, wearing a face mask when using the paint is still recommended. Also, spray outside or in a well-ventilated area.
Best spray paint to use on foam board
This professional spray paint from Liquidex doesn’t come with the problems associated with most aerosol products. It’s not messy and doesn’t smell or feel toxic. It provides an even distribution with a color that is true to the chart.
Since it’s water-based, it’s perfect for foam board and won’t melt it. You can use it on even older and more susceptible foam planes.
The paint comes in a rainbow of colors (up to 12), which you can use on various materials, including styrofoam, canvas, wood, glass, ceramic, and even masonry. Each color contains excellent art pigments made using basket bead-mill technology, providing great color development and a stable archival finish.
You can use it for painting or to create special effects. It can match with colors of other acrylic paint from the same manufacturer, making it so handy.
Unlike regular spray paint, this is a low odor and won’t pose any serious problem to the lungs or sensitive noses. Also, it won’t irritate your eyes and skin as much as regular spray paints. Having said that, we still advise you to wear a face mask while using the paint.
Being low solvent also means the paint is non-flammable and is less likely to get into a flame easily.
Cleanup is easy and requires just soap and water. But it should be done while the paint is still wet. Once the paint dries, it becomes permanent and doesn’t move. So, there’s no problem with bleeding, even when you overspray.
This makes the paint ideal for both indoor and outdoor use. Each aerosol can is 12oz and covers up to 21 square feet.
The only drawback is that it takes a bit longer to dry. You can utilize this time to work on the paint surface and get more creative.
Also, despite lacking considerable VOCs, we still recommend using it outdoors or at least somewhere with good ventilation.
Ensure to follow the instructions about shaking the can before and frequently during use. To prevent clogging of the nozzle, spray upside down after each use.
What We Liked 👍
Perfect for fine art applications
No harsh odor
The color comes out as expected
Won’t melt your foam board (also works for styrofoam)
Easy to clean
What We Didn’t Like 👎
A little pricey
Clogging may occur (spray upside down to prevent this)
The Rust-Oleum LeakSeal is another durable spray that works great on foam boards. As the name implies, it is designed to seal leaks and cracks while creating a full barrier against water. This makes it perfect for various crafts and fast indoor and outdoor repairs.
Common places you can use it include pipes, air ducts, gutter, roofing, and much more.
It is also versatile and flexible enough to conform to any material. These include but are not limited to foam boards, metal, concrete, fiberglass, vinyl siding, PVC, concrete, fiberglass, asphalt, etc.
The paint dries to the touch in 30 minutes and covers up to 8 square feet. Once applied, it doesn’t sag or drip. And once dry, it creates a water-tight seal and leaves a nice, even finish that makes your paint job look professional. You have the option of top-coating it with latex or alkyd-based paint.
Before use, shake well and open all the windows if you’re working indoors. It’s best to stay outdoors.
Like most Rust-Oleum spray paints, clogging can be a problem. To prevent this, spray the can upside down; continue spraying until only gas comes out of the nozzle.
The paint is suitable for both interior and exterior surfaces. As earlier indicated, besides foam boards, they can be used to correct problems on gutters, piping, air ducts, roofing, and more. It is also effective for filling small holes, gaps, and cracks.
Once applied, the paint sticks and holds up well, even under pressure. It dries to a semi-smooth finish capable of withstanding abuse.
What We Liked 👍
Seals leaks and cracks
Provides rust and water protection
Can be top-coated with latex or oil paint
Does not sag or drip
Easy to use
Suitable for both interior and exterior surfaces
Works on a wide range of materials
What We Didn’t Like 👎
Not 100 percent transparent
A bit expensive
The Krylon Short Cuts is perfect for anyone looking for suitable spray paint for craft foam. It is long-lasting, versatile, and has a nice shiny finish that is great for arts, crafts, and hobby projects.
Talking about versatility, the paint comes in 22 colors, giving you more options to choose from. It’s hard not to find your preferred shade.
The paint is archival-safe, which means it will last longer. Keep the board or object in good condition to ensure it lasts longer.
As indicated earlier, this formula is designed for foam materials, including craft boards and styrofoam. It is completely free of acid and doesn’t cause any permanent damage to the surface.
Each aerosol can is only 3 ounces, which is quite small, making it perfect for smaller projects.
But despite having fewer ounces, it still provides decent coverage. We recommend getting more spray cans if you plan to cover a vast area.
Once dry, the paint leaves a clear gloss finish that is highly reflective and resistant to stain.
A few users complained about the nozzle getting clogged after using it occasionally. To prevent this, whenever you finish spraying, turn the can upside down and spray till only gas comes out.
What We Liked 👍
Achieves better coverage with minimal quantity
Easy to clean
Nice touch-up paint
Very smooth finish
Wide range of colors to choose from
What We Didn’t Like 👎
Coverage is not so coverage (a larger bottle would be preferred)
How to seal form board after spray painting
You don’t have to seal your foam board after painting, but doing so will ensure it lasts longer. Apply the wax sealant after daubing the last layer of paint. Ensure the top coat is dry before using the sealant.
The exact method for sealing foam boards depends on the type of sealant or product you’re using. We recommend two main options: acrylic sealer (e.g., mod podge) and varnish. Acrylic is the easiest to use, and cleanup is a piece of cake since you only need water and soap for the brushes (i.e. if you’re not using an aerosol can).
However, varnish requires a bit more effort since you’ve to apply it with a brush. Using spray varnish on foam board is not advisable as it won’t create the same level of protection.. This is because spray varnish is not usually as thick as regular varnish.
You can also use epoxy resin or something more specific, like a foam finish.
Whichever sealant you choose, you only need to apply a thin layer to protect the surface. Use a foam brush or regular paintbrush. Let it dry completely before you use the board.
As earlier indicated, follow the instructions for your specific sealant, especially the number of coats you need to apply and the drying time.
Even though you don’t want to seal the entire foam board, pay attention to the edges. This is important because the edges are more prone to degradation. Thus, sealing the edges will guarantee long-term performance.
How Do I Stop My Foam Board From Warping?
Warping typically occurs with cheap foam boards. It usually occurs while the board is drying after painting. Also, with most products, painting one side of the board can cause it to warp. Other factors that may be responsible are high pressure, moisture imbalance, tension problems, and uneven heat distribution across the breadth of the board. In addition, not sealing the paint correctly can cause warping, peeling, and color dullness over time.
To stop your foam from warping, you can apply a few tricks.
Use a Brush and Water
The easiest one is to brush water over the board. Dip a soft brush in a small amount of water, and apply it on the board. Keep your strokes smooth and subtle. Once you do this, the board should straighten out or return to at least semi-flat. If it’s partially flat, bend it in the other direction using a rope. Be careful not to bend it too far; otherwise, the board might shatter.
Paint the Other Side
Another thing you could do is to paint the other side of the board (i.e. if you painted only one side of the board). Use the same type of paint. After painting, allow the board to dry to the touch, then place a few weights on it to suppress it while it cures fully. This should fix the problem.
Set the board
As earlier indicated, sealing your foam board will extend its performance and prevent degradation, such as warping. Besides the sealants already mentioned, you can also use solvent-based primer, shellac, or running alcohol. With each product, always test on a scrap to ensure the solvent will not attack the foam. If there are no issues, apply it to both sides of the board simultaneously, following the manufacturer’s instructions.
FAQs – Can you spray paint foam board?
Will Spray Paint Stick To Foam Board?
Yes, it will, as long as the surface is well-prepped. Spray paint is a great choice for foam boards because it has less moisture than other options. It also dries faster than regular oil paints applied using a brush. The major caveat is to use spray paint with limited solvents, as that can melt the foam.
Does spray paint melt foam board?
It depends on the type of spray paint you use. Water-based spray paints are generally safe to use on foam boards. However, solvent-based sprays can dissolve the inner polystyrene foam. So, it’s best to stick with water-based sprays or acrylic.
Can pink foam board be painted?
Yes, a pink foam board can be painted. Like the regular white foam board, pink foam boards are porous, so you may need several aerosol cans depending on the type of design you want to achieve.
Can you paint craft foam board?
Yes, you can. Just like other foam products, craft foam boards can be painted. You can use watercolors, acrylic, or even specialty oil paints. Make sure to prime the surface before applying the paint. This will help the paint to stick better.
Is it OK to spray paint styrofoam?
Avoid regular spray paint on styrofoam, as it will melt the material. Regular spray paint contains harsh solvents, such as enamel, that eat up and dissolve styrofoam when applied. If you want to paint styrofoam, use acrylic or water-based paint.
Can spray foam insulation catch fire?
Yes, it can. All types of insulation are flammable and can ignite and burn if exposed to sufficient heat sources. However, some spray foam insulation is treated with fire retardants to reduce flammability. These products often have a fire rating, indicating how long the material can resist being exposed to fire or a standard heat source.
Summary – Spray painting foam board
To conclude, you can spray paint foam boards just like other foam products. Make sure you take time to prepare the surface and use the right type of spray paint.
Acrylic paint is the top choice for foam boards. It is fast-drying and doesn’t melt the material like oil-based paints. There are other paint options, such as tempera and latex.
Use thin coats and spray in a well-ventilated area for the best results.
We will draw the curtains here. Feel free to drop your suggestions or any other questions about using spray paint on the foam board.