Is Acrylic Paint Waterproof? How to Weatherproof

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Acrylic paint is fun and easy to work with, and one of my favorite mediums. When I teach paint and sip classes, I am often asked many questions about acrylic paint, including whether or not it is waterproof.

Acrylic paint is water-based. It dries quickly, and as I mentioned it is easy to work with. It is also generally less expensive than oil paint.

While acrylic paint is convenient to use, there are some drawbacks. These drawbacks include durability and water resistance.

Today we are going to take a look at just how water-resistant acrylic paint really is, and how you can protect your paintings if they are exposed to moisture.

Keep on reading to learn more.

Is Acrylic Paint Water-Resistant?

Unfortunately, acrylic paint by itself is not waterproof. But, it is quite water-resistant after it has dried. You can also take steps to make it even more water-resistant.

To do this, you will need to seal the artwork after you have finished painting. Also, the surface you are using, such as a canvas, will play a role in the water resistance.

It may be necessary to prep the surface before you begin painting. I always do this anyway, just to keep the paint from seeping through the canvas. All you need to do is apply a couple of coats of gesso to prepare a canvas for painting.

Even after a painting has been sealed, chances are it is still not going to be completely waterproof. Dry acrylic paint is only a bit water-resistant. It can still succumb to chipping and peeling if it becomes wet.

How Acrylic Paint Works

We all know that acrylic paint dries quickly. This is because it is water-based, so the water evaporates quickly, allowing the paint to dry quickly.

Acrylic paint is made up of pigment that is mixed with an acrylic polymer emulsion. The emulsion is what makes the paint dry quickly.

This type of paint has a binder of acrylic resin. This is what makes the paint adhere to the surfaces you paint on. It separates the pigment and keeps everything together once the paint has dried.

The pigment is where the color comes from. Pigments start as powders, and they must be mixed with the other ingredients to become paint.

Finally, acrylic paint contains water, which is what gives the paint its fluidity.

Why Should Acrylic Paint Be Waterproofed?

Many of my paint and sip students ask me whether or not acrylic paint will wash away in the rain if they have painted something for outdoor use. They also want to know if acrylic paint is waterproof once it is dry.

When something that is painted with acrylic paint is exposed to the elements, chances are it is going to become damaged over time. Water that is spilled or rain will thin the acrylic paint out. Also, the paint can absorb water. 

So, does acrylic paint wash off in rain?

The answer unfortunately is yes, the rain can wash away the acrylic paint. When acrylic paint is applied to an untreated surface and is still wet, rain can cause it to wash away. Once the paint has fully dried, it becomes somewhat water-resistant, but over time, it may begin to peel or flake off. 

To weatherproof your acrylic-painted surfaces from rain damage, it is recommended to apply a protective sealant or varnish. This additional layer helps enhance water resistance and prolongs the lifespan of the paint.

If you are painting something that is going to be kept outdoors, it is important to take steps to waterproof the piece. That way you can be sure that it is going to look great for a long time to come.

Do You Need Special Tools to Waterproof Acrylic Paint?

While you don’t necessarily need to use any special tools to waterproof your acrylic paintings, it is a good idea to use the right kind of brush to apply the varnish that will protect the paintings.

I like to use a foam poly brush. This is the best type of tool for this purpose because it will soak up the varnish so you don’t end up applying too much. You will get a coating that is nice and even.

If you are going to use this method, I recommend being very careful while you are working. Try not to leave any fingerprints behind, because they will be there forever. When using a brush, be sure to use even brushstrokes. Do not allow the brush to sit on one area for any length of time to avoid leaving brush marks.

I also like to use Krylon spray varnish. This also gives you an even coating, and it is so easy to use. You can find this in art supply stores and even in most hardware stores.

How to Waterproof Acrylic Paint

Yes, acrylic paints are quite durable, but they still need to be waterproofed to prevent future damage caused by moisture. Some people say that this must be done while the paint is still somewhat wet.

I have had difficulties with this because using a brush to apply varnish has caused the wet paint to smear. I have had much better luck waterproofing wet paint with spray varnish.

If you are going to use varnish, you will need to use a special varnish that is made for acrylic paintings. It is an acrylic gloss. Not only does it protect your painting, but it also adds a nice shine.

#1. Waterproofing Canvas Paintings

If you are painting on canvas, it will need to be waterproofed, both before and after painting. Start by priming the canvas with gesso or another primer.

Once the canvas has been primed, then you can start painting. After the paint is dry, spray it with a UV-protective spray to give it an extra layer of protection from UV rays.

Next, you will need to add a layer of varnish. If the painting is going to be outdoors, I suggest using two to three coats of outdoor polyurethane. Each coat should be dry before applying the next coat.

#2. Waterproofing Paintings on Metal

Acrylic paints are ideal for painting on metal because they are not reactive and they will adhere well to metal surfaces. You can paint just about any metal object with acrylic paint.

Once you have finished painting, you will need to take steps to protect your work. For this, all you need is one coat of varnish that is made for use on metal.

#3. Waterproofing Paintings on Glass

Finally, I would like to talk about waterproof paintings that are done on glass. Acrylic paint works well on glass, and it is easy to waterproof.

Paint on glass the design that you wish to create. Then, allow the paint to completely dry for at least 24 hours. This will give the paint plenty of time to properly set.

There are a couple of ways that you can set the paint. One way is to place the item in the oven. Turn the oven to 350 degrees Fahrenheit, and allow the oven to heat up while the object is inside. This will keep the glass from cracking.

Bake the glass in the oven for about half an hour. Then, turn off the oven and allow the glass to cool in the oven for about 72 hours.

You can also use a hairdryer on low heat, but this takes several weeks. I prefer using the oven method to bake the paint.

Conclusion

If you are going to be creating anything with acrylic paint, please make sure that you take the proper steps to make sure it is waterproof. As I have said throughout this post, acrylic paint is not waterproof on its own.

It doesn’t take a lot of time or effort to make sure a painting is waterproofed, and it is well worth it if you want your paintings to last for many years. You can paint indoor and outdoor items, and know that they will look great for a long time as long as they are properly waterproofed.

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