Is Acrylic Paint Waterproof? Only If You Do This…

A variety of hand-painted garden rocks outside on a boulder.

Acrylic paint is a versatile paint that can be used for both indoor and outdoor projects. It is water based, making it a low-toxicity, easy-to-clean up choice.

Acrylic paint can be applied effectively to many different materials, including wood, metal, plastic, glass, and fabric, but will it last?

Is acrylic paint waterproof? Acrylic paint is not waterproof, but it does tend to be water resistant. If you want your acrylic paint to be waterproof, you will need to apply a waterproof sealant after painting. Depending on the surface, use polyurethane, varnish, or a sealant designed specifically for acrylics.

In this article you will learn why acrylic paint is not waterproof as well as how to waterproof acrylic for multiple surfaces.

You will also learn how to apply acrylic paint to outdoor surfaces and how to remove acrylic paint.

Why Acrylic Paint Is Not Waterproof

Acrylic paint is water based, making it easy to clean up and quick to dry.

It is water soluble when wet and water resistant when dry, but exposure to moisture or humidity can result in wearing away of the paint. 

About Acrylic Paint

Acrylic paint consists of two main ingredients: pigments and binder. Pigments are what gives the paint its color, while binder is what makes the paint adhere to surfaces.

The kind of binder used in acrylic paint is an acrylic polymer emulsion.

An emulsion is a dispersion of one liquid within another. In the case of acrylic paint, the emulsion contains acrylic resin suspended in water. 

Due to its water-based nature, acrylic paint reacts differently to water when it’s wet versus when it is dry.

When acrylic paint is wet, water can be added to the paint to thin it, or water can be used to clean the paint completely off of a surface. 

As acrylic paint dries, the water evaporates, leaving behind a water-resistant acrylic polymer film.

Once acrylic paint is dry, you will need to use solvents or cleaners along with a little elbow grease to remove the paint. 

Is Outdoor Acrylic Paint Waterproof?

Outdoor acrylic paints are not considered waterproof.

They are often sold as “weather resistant,” meaning that they contain additives that make them hold up better against exposure to the elements and excess moisture.

The Difference Between Water Resistant and Waterproof

A water-resistant paint is able to resist penetration from moisture to an extent…but not completely.

Water-resistant paints are good choices for temporary outdoor projects, such as painting pumpkins for Halloween or a short-lived holiday design on a window. 

Waterproof paints (such as marine paints) are designed to withstand heavy exposure to water and won’t wash off no matter how much moisture they are subjected to.

Waterproof paints tend to be much more difficult to remove than water-resistant paints and will usually need to involve the use of a heavy-duty solvent or cleaning agent for removal.

How To Make Acrylic Paint Waterproof

The best way to make acrylic paint waterproof is to use a waterproofing sealant over the paint once it is dry.

You can also improve the water resistance of acrylic paint by applying primer before painting and using multiple coats of paint.

Waterproofing Acrylics on Glass

In order to properly waterproof acrylic paint that has been painted on glass, your best bet is to choose a sealant that is specifically designed for use on glass surfaces.

Choosing a polyurethane sealant or varnish with a glossy finish can really make acrylic paint on glass stand out. 

Aleene’s Acrylic Sealant Gloss Finish is an excellent choice too.

It’s designed specifically to protect acrylic paint on a variety of surfaces, including glass, can be used for indoor and outdoor projects, and won’t yellow over time.

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Aleene's 26412 Spray Gloss Finish, 6 Oz Acrylic...
  • Acrylic sealer spray provide a protective, clear finish
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Even though your glass product should be entirely waterproof once sealed, it’s always best to avoid running it through the dishwasher.

If you need to wash the item once it’s been sealed, use water and a gentle detergent to hand wash the painted glass. 

Waterproofing Acrylics on Wood

In order to properly waterproof acrylic paint on wood, you will want to first apply a coat of primer to the wood surface.

Once the primer has completely dried, you can apply at least two coats of acrylic paint. You may need to wait several days for the paint to dry enough to handle.

Once the paint is dry, you will then want to apply a thin, even coat of a glossy polyurethane varnish, like this interior/exterior option, or sealant over the paint.

(I share several other options to use here.)

Depending on how much the wooden object will be handled, you may need to apply several coats of varnish.

Make sure each coat is completely dry before applying the next. It’s a good idea to wait at least a week after applying the final coat of varnish before handling the item. 

Minwax Helmsman Indoor/Outdoor Spar Urethane,...
  • PROTECTIVE CLEAR FINISH – Minwax Helmsman Spar Urethane is specially formulated as a protective...
  • EFFECTIVE YEAR ROUND – This wood varnish forms a protective barrier against rain and moisture to...

Waterproofing Acrylics on Plastics

To waterproof acrylic paint on plastic, follow the same steps as with waterproofing wood. Make sure that each layer is totally dry before applying the next layer. 

Polymer varnishes are a good choice for waterproofing acrylics on plastic and can be applied with a wide brush.

Apply the varnish in a horizontal fashion, first brushing in one direction, and then going back over the layer in the opposite direction. 

Liquitex makes a good one (find it here), and it is a company that has earned my trust over the years.

Liquitex Professional High Gloss Varnish, 118ml...
  • Archival; Permanent; Non-Removable; Gloss finish
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Waterproofing Acrylics on Fabrics

The best way to waterproof acrylics on fabrics is to either use a fabric medium that can be mixed into regular acrylic paints or to use acrylic fabric paints.

If you choose to mix acrylic paint with fabric medium, go with the best – Angelus. You should combine them at a 1:1 ratio.

Angelus 2-Soft Fabric Medium Additive For Acrylic...
  • Angelus 2-Soft is a must-have when working on soft, flexible fabrics such as the sock-liner of...
  • Heat-set to maintain softness

Make sure to heat set the fabric once the paint is dry and to wash the fabric in a gentle wash cycle and dry on a low heat setting afterward. 

Be sure to check with my article, Painting Fabrics With Acrylic Paint for complete directions and helpful tips.

Waterproofing Acrylics on Metal

First choose a varnish made specifically for metal. Wait at least 24 hours for the final coat of paint to dry before applying the metal varnish.

Apply the metal varnish in thin, even coats, waiting at least 5-10 minutes between application of layers, depending on the particular brand’s instructions.

I recommend Americana as it provides great, even coverage with just one coat.

Americana Acrylic Sealer/Finish Aerosol Spray...
  • Americana acrylic sealer/finish aerosol spray
  • Provides a protective coating that dries quickly and to an even durable finish

Don’t miss out on my full guide to using acrylic paint on metal. You’ll find clear, easy-to-follow instructions for every stage of the process.

How To Seal Acrylic Paint for Outdoor Use

You can use a brush or spray-on variety of varnish for outdoor projects. Spray varnishes are often easier to apply to large, flat surfaces.

Make sure that the surface is clean and dry before applying the first coat of varnish.

If you’re using a spray varnish, be sure to hold it at least 12” away from the material that is being sprayed.

It’s a good idea to let each layer of varnish dry completely before applying the next and to use several coats. 

Related Questions:

Is Acrylic Paint Good for Outdoor Use?

Acrylic paint is good for outdoor projects, but it should be combined with a primer and a high-quality sealant in order to protect it from the elements and exposure to moisture.

How Do I Remove Acrylic Paint?

To remove wet acrylic paint, simply wash it off with water. Once the paint has dried, you can try soaking a paint stain in rubbing alcohol and using a scrub brush to remove the paint.

If that doesn’t work, you can try acetone or lacquer thinner, which contain harsh chemicals but can be good at removing dried acrylic paint.

Find more tips on removing acrylic paint from a variety of materials in my article here.

Conclusion

Acrylic paint isn’t inherently waterproof,  but thanks to the magic of technology and chemicals it certainly can be!

It’s a good idea to first apply a primer to the surface you intend to paint, follow that with multiple coats of paint, and finish with a sealant.

The varnish should be effective at waterproofing your painting!

Last update on 2022-09-25 at 08:49 / Affiliate links / Images from Amazon Product Advertising API

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Cara

Cara

I am a writer and an artist taking opportunities every day to transform my dreams into reality. I love learning new things and am always creating and innovating. I worked as an Art Instructor, teaching painting and art techniques to artists of all levels and ages. I have hosted countless paint parties and taught children’s art classes both in my home as well as an art teacher at a Montessori school.