How to Seal Acrylic Paint on Plastic- Expert’s Guide

Is your plastic surface or furniture fading or losing its effervescence to the extent that you’re thinking of replacing it? Rather than tossing it away, applying some topcoats/ seals on the acrylic paint will bring the surface back to life. Plastic, unlike wood, is challenging for getting acrylic paint to stick.

Moreover, acrylic paint tends to peel off after a while, so sealing it is the best chance of making the paint last longer while it still retains its aesthetic finish. In this post, we will discuss how to seal acrylic paint on plastic.

What Is an Acrylic Paint?


Acrylic paint is a mixture of pigment in acrylic polymer emulsion. Acrylic paint is a water-based paint that quickly dries when applied on a surface. Because it’s water-based, the paint’s water evaporates rapidly, quickening the paint’s drying time.

Acrylic paints are great paints for many objects, plastics, and pieces of furniture. While the paint sticks to painting surfaces like plastics, the color will wash off when the painted surface (plastic) is exposed to water. This could end up destroying your painted surface.

Can you paint plastics with acrylic paint?

Acrylic paints may be all that hard and robust when it’s dry, but a little water spill could ruin the paint on the plastic. Moreover, acrylic paints are not waterproof – they are only resistant to water to an extent because it’s a polymer. So it can absorb little water, which is why you need to seal the paint.

Additionally, they don’t usually hold up well to severe, frequent handling, as other paints. They also work better on surfaces that are aerated like wood than plastic.

For this reason, sealing the paint with varnish will help protect the paint from water damages and preserve its beautiful design. Using a sealer will seal the plastic painting permanently. If you don’t seal it before the paint cures, your marvelous plastic painting could be in a mess.

What to Use to Seal Acrylic Paint on Plastic?

An acrylic sealer like varnish will seal acrylic paint on your plastic and protect the layer from damages. What’s a Varnish and Why Would It Help? The varnish is a durable finish that you can use to protect a painted material. To apply varnish on acrylic paint means adding a protective topcoat to seal the finished painted material.

There are many reasons why you would want to varnish your painting. Whatever the reason might be, applying varnish on a surface will add some protective sealing, thereby making the paint last longer.

Now, why would varnishing help? As we said, varnishing paint like acrylic will protect the paint from dust, debris, accidental water spill, and fading when exposed to light or the sun rays.

That means if you varnish acrylic paint and then spill some water on it, you don’t need to be bothered about the color getting damaged. It also makes the paint colors look richer and more beautiful because varnish adds some reflective sheen to the acrylic paint.

What Constitute a Varnish?

You may want to ask what makes up a top sealant like a varnish. Well, the answer is not far-fetched, as varnish isn’t made up of so many ingredients. The varnish is made up of these main ingredients; resin, solvent, oil, driers, etc.

Read Also: Can You Put Polyurethane Over Acrylic Paint?

How to Seal Paint on Plastic?

  • If your plastic is already painted, and you’re looking for ways to seal permanently, at least for a long time, here are the steps to do so;
  • Wipe the surface clean with a lint-free cloth.
  • Gently sand the surface with less coarse sandpaper to get rid of uneven spots.
  • Clean the dust with a tack cloth.
  • Your plastic painting must be placed vertically in a dust-free environment.
  • You can place your painting on a board or something very flat for convenience.
  • Use the brush-on or spray-on method. I advise that you use the spray-on method when sealing plastic to get the best result.
  • Shake and spray the varnish on the acrylic paint.

However, if you want to brush the paint instead of spraying it, use the base coat brush and follow the steps below;

  • Ensure that your acrylic painting is dry if you recently painted. For the best result, I advise that you wait for about 24 hrs.
  • Pour a small quantity of your sealer into a bowl. Apply the first coat with a base coat brush. Using this brush is because of its soft bristles, as they would adhere the sealer well on the plastic.
  • Apply the first coat in gentle, horizontal/ vertical strokes, and make sure your application goes all round.
  • Also, it would be best to work in an area that’s bright and sunny.
  • Allow the first coat to dry. Usually, the waiting time is three hours, but you could stay longer for the best result.
  • While you wait, ensure your bowl and brush are covered. If you wish, you can rinse the brush so that the varnish doesn’t dry up on the brush.
  • Apply a second coat, and ensure the application is even.
  • Wait for the coat to dry. Two coats are usually okay, but you can apply a third if you want.

How to Paint Plastic with acrylic paint

If you haven’t painted your plastic yet, there would be no need to apply a sealer. Painting plastic is almost as easy as sealing it when it’s already painted. All you have to do is follow the steps meticulously.

The best way to paint plastic is to use spray paint. Although paints are designed for plastic painting, I prefer spray paint, as it results in a more natural-looking, glossy appearance.

Be sure to purchase the right spray paint for use on plastic. The wrong paint type may cause bubbles, flakes, or won’t adhere to plastic surfaces properly. Look for spray paints that are formulated for plastic surfaces. Brands like Rustoleum, Krylon, and Valspar are great brands that manufacture spray paints for plastics.

Tools Needed

  • Spray paint
  • Rubbing alcohol
  • Painter’s tape
  • Mild soap
  • Fine-grit sandpaper

Below are the steps you should follow.

Prepare the area that you want to paint thoroughly. Adequate preparation is necessary because it determines the outcome of your finish. Clean the plastic surface with mild soap and water to get rid of dust and any other thing that may hinder your painting’s smoothness.

  • Allow the plastic to dry.
  • Use fine-grit sandpaper and rub it gently over the surface. This is rough up the surface a little so that the paint can adhere to it better.
  • Once you are done, wipe it down with rubbing alcohol and allow it to dry.
  • Secure the area with a tarp. This is optional but essential in minimizing work hazards.
  • If there’re any plastic areas that you don’t want to paint, cover such areas up with painter’s tape.
  • Hold the spray paint’s nozzle at approximately 20 inches away from the plastic. Start spraying from one spot and spread across to the other side of the surface. Spray in a gentle, smooth motion.
  • Continue to do so until the entire area is covered. Avoid over-spraying.
  • Allow the paint to dry.
  • At this point, you can choose to apply an acrylic sealer to protect the paint. I advise that you use an acrylic sealer if the painted plastic spends more outdoors than indoors.

What Paint Stays On Plastic If You Don’t Want to Seal Acrylic Paint?

There’s every possibility that you may still need to seal acrylic paint after painting it. However, there’re paints that you can use on plastic that may prevent sealing the acrylic paint, at least, for a few years.

These paints include paints; Rust-Oleum Corporation Painter’s Touch 276116 Spray Paint, Rust-Oleum 249079 Painter’s Touch, Krylon K04293000, Testors Acrylic Value Finishing Paint, etc. These paints will adhere to plastic surfaces better.

How Do You Make Acrylic Paint Look Glossy?


Most people would want to make acrylic paint on their plastic material look glossy. It’s not entirely impossible to make acrylic paint look glossy; all you need is the right mixture.

  • Mix a gloss medium into the paint you want to use on a palette, and then apply. Alternatively, you can usually paint and then apply a high gloss varnish over the painting when it’s scorched.
  • Is Nail Polish a Good Acrylic Paint Sealer?
  • If you want to seal acrylic paint, I advise that you avoid nail polish. First off, it may react badly with the paint.

Secondly, it’s expensive and generates fumes when using it. Thirdly, it doesn’t remain evident, even after drying. More so, it becomes yellow over time.

Generally, nail polish is unsafe for plastic painting. It’s volatile and not designed to last long on plastic paintings.

Conclusion- How to Seal Acrylic Paint on Plastic- DIY Complete Guide

If you want acrylic paint on your plastic to last long and still maintain its aesthetics, sealing it the best thing to do. Aside from prolonging the paint’s lifespan and preserving its beauty, sealing also protects it from damages.

Thanks to this detailed guide, I’m confident that you have an idea of how to seal acrylic paint on plastic and paint plastic with durable paint.

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