Is Acrylic Paint Waterproof? How to Protect Your Artwork Outdoors

Acrylic paint is a favorite among artists and DIY enthusiasts because of its versatility, vibrant colors, and quick drying time. But if you’re planning to use it for outdoor projects or in a humid environment, you might be wondering: is acrylic paint waterproof? While acrylic paint is water-resistant once dry, it’s not fully waterproof on its own.

To make it last through moisture and weather, you’ll need to apply a protective sealant. In this guide, we’ll dive deeper into how to ensure your acrylic projects stand up to water and the elements.

Is Acrylic Paint Waterproof Once Dry?

When acrylic paint dries, it forms a flexible, plastic-like surface that makes it highly durable and resistant to damage. However, despite its resilience, acrylic paint is not fully waterproof on its own. While it becomes water-resistant after drying, meaning it can withstand light moisture or a quick splash of water, prolonged exposure to water can cause the paint to soften or degrade over time.

Water resistance refers to its ability to repel water to a certain extent without absorbing it immediately. However, without additional protection, such as a sealant or varnish, acrylic paint can still be vulnerable to rain, heavy moisture, or even repeated washing, especially when applied on porous surfaces like wood or canvas. The surface underneath the paint could absorb moisture, leading to peeling, fading, or other damage over time.

If you’re using acrylic paint on indoor projects or surfaces that won’t encounter much moisture, the paint’s natural water resistance will likely suffice. But for outdoor projects or pieces in high-moisture areas like bathrooms or kitchens, you’ll need to take extra steps to make your acrylic paint waterproof.

Sealing the paint with a waterproof varnish or sealant provides a protective barrier that locks in the paint’s color and ensures it holds up against water, humidity, and wear.

In summary, while acrylic paint is resistant to water once dry, it isn’t fully waterproof. For added durability and long-lasting results, especially in wet or humid conditions, it’s essential to apply a proper sealant.

How to Make Acrylic Paint Waterproof

If you’re using acrylic paint for a project that will be exposed to water, moisture, or outdoor elements, simply letting it dry won’t make it waterproof. While acrylic paint is naturally water-resistant, you’ll need to take extra steps to ensure it becomes fully waterproof. Here are some effective methods to make your acrylic paint projects water-tight and more durable:

1. Apply a Waterproof Varnish or Sealant

One of the easiest and most reliable ways to waterproof acrylic paint is by applying a clear varnish or sealant. These products are specially designed to create a protective barrier over your painted surface, shielding it from moisture, dirt, and damage.

Types of Sealants: There are different types of sealants you can use, such as spray-on or brush-on varnishes. A spray varnish is convenient for covering larger areas evenly, while a brush-on varnish gives you more control over the application. You can choose between gloss, matte, or satin finishes depending on the look you want for your project.

How to Apply: Make sure your acrylic paint is completely dry before applying the sealant. Spray or brush a thin, even layer of varnish over the surface. Allow it to dry fully before applying additional coats. For the best protection, it’s recommended to apply two to three coats of sealant.

2. Use a Waterproofing Medium

Acrylic mediums are another great option for waterproofing your paint. These mediums can be mixed directly into your acrylic paint before application to enhance its water resistance. This method is ideal for projects where you want to add texture or depth without affecting the final appearance of the paint.

How It Works: By blending a waterproof medium with your acrylic paint, you create a mixture that not only applies color but also dries with a water-resistant finish. This means you’re building the waterproofing element directly into your paint layers.

Application Tips: Follow the instructions on the medium’s packaging for proper mixing ratios. Apply your paint as usual, and once dry, you can still add a final sealant for additional protection, especially for outdoor projects.

3. Use a Waterproof Clear Coat

If you’re working on a larger or more demanding project, such as furniture or outdoor decorations, you might consider applying a heavy-duty waterproof clear coat. Products like polyurethane or polycrylic are often used for wood surfaces but can be applied over acrylic paint as well.

Polyurethane vs. Polycrylic: Polyurethane offers a stronger, more durable coating that’s great for outdoor projects, while polycrylic provides a water-based alternative that’s easier to clean and less likely to yellow over time. Both options will provide excellent waterproofing.

Application Process: Make sure your painted surface is completely dry before applying the clear coat. Using a brush or a foam applicator, spread an even coat over the entire surface. Let it dry completely before applying additional layers. Like varnish, two to three coats of clear coat are typically recommended for maximum protection.

4. Waterproofing Fabric and Clothing

If you’re using acrylic paint on fabric, waterproofing becomes a bit more challenging since fabric is naturally more absorbent. In this case, a fabric medium is essential to mix with your acrylic paint. After the paint has dried, you’ll also want to add a fabric sealant to lock in the color and protect it from water damage.

Steps for Waterproofing Fabric:

• Mix the fabric medium with your acrylic paint before application.
• Paint your fabric and allow it to dry fully.
• Once dry, apply a fabric sealant or spray to waterproof the painted area.
• Let the sealant dry, and for extra durability, heat-set the paint using an iron (follow the instructions on the fabric medium or paint for the best results).

5. Consider Using Outdoor-Specific Acrylic Paint

If your project is primarily for outdoor use, you can also opt for outdoor-specific acrylic paint. These types of paints are formulated to be more durable and weather-resistant, but it’s still a good idea to seal them for added longevity.

These paints are designed to withstand UV rays, rain, and temperature fluctuations, making them ideal for outdoor furniture, garden decor, or murals. However, for optimal results, sealing the paint with a varnish or clear coat is still recommended.

6. Avoid Excessive Water Exposure Even After Sealing

While waterproofing techniques make your acrylic paint far more resistant to water, it’s important to note that no product is completely immune to the effects of long-term or heavy water exposure. After applying sealants or clear coats, avoid exposing your painted project to excessive water or soaking, as this can eventually wear down the protective layers over time.

Can You Use Acrylic Paint Outdoors?

Yes, you can absolutely use acrylic paint outdoors, but there are important factors to consider to ensure your project holds up against the elements. Acrylic paint is known for its versatility, vibrant color, and quick drying time, making it a popular choice for outdoor art projects such as murals, garden decorations, and even outdoor furniture.

However, while acrylic paint is water-resistant, it is not naturally waterproof, which is a crucial distinction when it comes to outdoor use.

Durability of Acrylic Paint Outdoors

Acrylic paint dries to a flexible, plastic-like surface that can handle some exposure to the elements, like sunlight and mild rain. However, because it isn’t fully waterproof, outdoor use exposes the paint to risks like fading, peeling, and cracking over time due to weather conditions like rain, humidity, and temperature fluctuations. Without proper protection, the paint might not last as long as you expect.

• UV Resistance: Sun exposure can cause colors to fade, especially in acrylic paints that aren’t labeled as UV-resistant. If you’re painting something that will spend a lot of time in direct sunlight, make sure to choose a paint with UV protection or apply a UV-resistant varnish afterward.
• Temperature Changes: Acrylic paint dries to a somewhat flexible finish, which means it can expand and contract with temperature changes. This flexibility helps prevent cracking in areas that experience a wide range of temperatures. However, in extreme temperatures, unsealed acrylic paint can become brittle and crack over time.

Why Sealing Is Important for Outdoor Projects

If you plan to use acrylic paint on an outdoor project, one of the most important steps you can take is to apply a protective sealant once the paint is dry. The purpose of sealing is to make the paint fully waterproof and ensure it withstands moisture, rain, and even prolonged sun exposure.

• Waterproofing: Acrylic paint on its own can repel some water, but prolonged exposure to rain or heavy moisture can cause the paint to degrade. Applying a waterproof varnish or sealer will protect your project from moisture, making it safe to use acrylic paint outdoors, even in areas prone to rain.
• UV Protection: Many outdoor varnishes or sealants offer UV protection, which prevents your colors from fading or yellowing over time. This is especially important for outdoor murals or decorations that will be in direct sunlight.

Best Practices for Using Acrylic Paint Outdoors

To maximize the longevity of your outdoor acrylic projects, here are some best practices to follow:

• Prep Your Surface: Whether you’re painting on wood, metal, concrete, or canvas, proper surface preparation is key. Make sure the surface is clean, dry, and free of any debris. For certain materials like wood or metal, it may be necessary to apply a primer before painting to ensure the acrylic paint adheres properly.
• Choose High-Quality Outdoor Acrylic Paint: If your project is mainly outdoors, consider using acrylic paint specifically labeled for outdoor use. These paints are designed to withstand weather conditions better than standard acrylics. They typically have higher UV resistance and are more durable when exposed to the elements.
• Apply Multiple Coats: One of the simplest ways to enhance the durability of acrylic paint outdoors is by applying multiple thin coats. Each layer adds strength to the paint film, creating better coverage and a more protective surface.
• Use a Waterproof Sealer: Once your acrylic paint is completely dry, it’s essential to apply a waterproof sealer or varnish to protect the paint from water, dirt, and UV rays. There are different types of sealants available—some are spray-on for ease, while others are brush-on for more precision. Be sure to use a product that is designed for outdoor use.
• Regular Maintenance: Even with proper sealing, outdoor projects may need occasional touch-ups or reapplications of sealant over time. Regularly inspect your project for any signs of wear or damage from the weather, and make repairs as needed to keep it looking its best.

Outdoor Surfaces Suitable for Acrylic Paint

Acrylic paint can be used on a wide variety of outdoor surfaces, but some are better suited than others. Here are some common materials where acrylic paint can be successfully applied outdoors:

• Wood: Acrylic paint works well on wood, but because wood is porous, it can absorb moisture, leading to swelling, cracking, or warping. Sealing the wood both before and after painting can prevent these issues.
• Metal: When painting metal, it’s important to prime the surface first, especially if the metal is prone to rusting. Acrylic paint can adhere well to primed metal surfaces, but like wood, it needs to be sealed to protect from moisture and corrosion.
• Concrete and Brick: Acrylic paint can be applied to concrete and brick surfaces, such as walls or garden planters. These materials are often porous, so applying a primer and a waterproof sealant will help ensure the paint lasts.
• Canvas: For outdoor murals or large-scale artwork, acrylic paint can be applied to stretched canvas. Just make sure to seal the canvas afterward to protect it from moisture and UV exposure.

Considerations for Harsh Climates

If you live in an area with extreme weather conditions—like heavy rainfall, snow, or intense heat—it’s even more crucial to take the necessary steps to protect your acrylic paint projects. In these climates, unsealed acrylic paint will degrade faster, and the elements can cause severe fading, cracking, or peeling.

In extreme conditions, you might also want to consider using a heavy-duty clear coat, such as polyurethane, for an extra layer of protection. While this adds more time and effort to the process, it will significantly extend the lifespan of your outdoor acrylic paint projects.