How To Fix Cracked Acrylic Painting On Canvas | Prevent\Repair Cracks |

It is really frustrating to see acrylic paint on your hardly painted surfaces getting cracked or peeled overnight. You might be thinking of discarding these ruin-out paintings, but wait! There are ways to repair these imperfections. So let’s see how to fix cracked acrylic paint. 

Acrylic painting cracks can be fixed by light sanding and refilling the surface with a fresh coating of paint. Another way is scratching the broken paint to reuse canvas or the painted surface. 

I can understand the concern of beginners as I’ve passed through this stage. I used to get cracks in my paintings when I was a newbie, but once I explored the reasons and applied the preventions practically, I never got disappointed. 

In the post below, I’ll guide you through essential steps to fix acrylic painting. Moreover, I’ll give you preventive tips on how to avoid these cracks. So keep reading! 

Reasons Behind Acrylic Paint Cracking

Reasons Behind Acrylic Paint Cracking

There are several reasons why acrylic paint cracks. Some of the most significant and avoidable causes include: 

  • Improper Surface Preparation

If the surface of your canvas, plastic, paper, etc., is not prepared properly, it can lead to adhesion issues and paint cracking when dry. 

The presence of dirt, oil, grease or other contaminants on the surface due to lack of cleanliness, which can prevent proper bonding of the paint, leads to cracking and peeling over time.

Similarly, Improper surface smoothing or filling can also cause an uneven surface that can result in paint cracking. Another important factor is not priming the surface, which weakens the adhesive properties of the paint. 

  • Too Thin Coating

Applying too thin coats of acrylic paint can result in cracking as the paint dries and contracts. Thin coats of paint crack due to a lack of flexibility and adhesion. 

When the paint is applied in thin coats, it has less ability to expand and contract with temperature changes and surface movements, leading to cracking. 

Additionally, thin coats have less paint to grip onto the surface, making them less sticky and more susceptible to chipping and cracking. 

To avoid this, it is recommended to apply at least two layers of paint with sufficient thickness, allowing proper drying time between coats and ensuring proper preparation.

  • Too Thick Coating

Another important factor that contributes to painting cracking is applying the paint thickly at once. This is because acrylic paint dries through evaporation and as it dries from the surface inwards. So, the outer layer will shrink faster than the inner layer, causing cracks to form. 

Additionally, thick layers of acrylic paint can also trap moisture underneath, leading to further problems such as bubbling, blistering, and mold growth. 

To avoid these issues, it’s recommended to apply thin, even coats of acrylic paint and to allow each coat to dry completely before applying the next one.

  • Extreme Temperature Changes

Sudden and drastic temperature changes can cause the paint to shrink and crack because acrylic paint is a thermoplastic, meaning it becomes more pliable when heated and stiffens when cooled.

When the paint is applied in a thick layer and subjected to temperature changes, the underlying layers may contract at a different rate than the surface, causing cracking.

Additionally, quick temperature shifts can cause the paint to expand and contract rapidly, leading to the formation of gaps.

Learn more: Is acrylic paint heat resistant?

  • Moisture 

Moisture also contributes to acrylic paint cracking because it disturbs the structure of the paint. When moisture is absorbed from air or any other source, the paint starts expansion, eventually producing cracks when it dries and shrinks.  

So, applying acrylic paint on a surface that usually gets damp from underneath is not advised. 

  • Low-Quality Paint

Low-quality paint can cause cracks in painting because it is often made with inferior ingredients that do not bind well to the surface being painted.

This can result in a brittle, weak paint film that is prone to cracking, especially in areas exposed to heat, moisture, and other environmental stressors.

Acrylic paint that has grown old and exposed to sunlight and weather for an extended period of time is more likely to crack.

How To Fix Cracked Acrylic Painting In 5 Steps?

Acrylic paint is a popular choice for artists due to its quick drying time and ability to mix well with other mediums. However, it can crack over time, especially if applied to a non-porous surface or used faulty techniques. 

But no worries, the problem can be resolved with this procedure. Here’s a step-by-step guide on how to repair cracked acrylic paint:

How To Fix Cracked Acrylic Painting (Step-by-Step Procedure)
  1. Clean The Surface 

Clean the surface where the cracked paint is located with a soft cloth and use mild soap to remove any dirt or debris. You may simply use a vacuum cleaner to get rid of the dust. Make sure the surface dries thoroughly before you proceed. 

  1. Sand Down The Cracks

The next step is sanding the affected area. For this purpose, use fine-grit sandpaper to gently sand the cracks. This will help to smooth out the surface and make it easier to repair. But sanding acrylic paint the right way needs focus and time.

  1. Prime The Surface

Apply a thin coat of gesso or another type of primer to the surface. This will help to provide a soft surface for the new paint to adhere to and prevent future cracking. Let the primer dry completely. However, priming is optional in this case. 

  1. Fill in The Cracks

Use a palette knife or putty knife to apply a small amount of acrylic paint or filler to the cracks. Use a light touch and try to fill in the cracks as evenly as possible. Let the paint dry completely.

Once the paint is dry, use fine-grit sandpaper again to gently sand the newly dried surface for a good finish. This will also help to remove any bumps or rough spots.

  1. Paint Over The Cracks

Apply a thin coat of acrylic paint over the entire surface, including the areas where you filled in the cracks. Let the paint dry completely.

Repeat steps five and six as needed until you achieve the desired level of smoothness and coverage.

TIPS: By following these steps, you can also repair acrylic pour cracking on any surface and restore its appearance. Remember to work slowly and carefully, and let each step dry completely before moving on to the next one.

You can also read on: How to fix lumpy acrylic paint?

How To Prevent Cracks In Acrylic Painting?

I believe that if you follow proper preventive measures, you never gonna get cracks or ruptures in your painting. In fact, most newbie artists ignore the manufacturer’s instructions, or they are still unaware of the right painting techniques. 

How To Prevent Cracks In Acrylic Painting

Here are the tips on how to prevent acrylic paint from cracking on shoes, plastic, metal, canvas, or any surface, which will help you get a smooth and consistent finish. 

  • Select a rigid, stable surface such as a gesso-primed canvas or panel to paint on, which will prevent warping and sagging over time. A soft or flexible surface is not recommended.  
  • Avoid overworking the paint, and allow each layer to dry completely before adding another. Also, avoid using excessive pressure when painting to prevent cracking from occurring.
  • A clear varnish or sealant will help protect the painted surface from cracking and discoloration. So I advise you must try varnishing the surface for a resistant top finish. 
  • Store your paintings in a cool, dry place, away from direct sunlight, heat, and moisture. When handling, avoid touching the painted surface and always lift the painting by its sides or frame.
  • Apply the paint in thin, even layers, allowing each layer to dry wholly before adding the next.
  • Avoid heavy brush marks by using a soft brush and light gliding strokes. Brush marks lead to lumps or cracks later on when the paint dries. 
  • If you are working with a thick layer of paint, you can use a palette knife to gently smooth the surface and remove any bubbles.

How To Fix Acrylic Paint Cracking With Acetone?

Acrylic can be repaired using a process called “welding.” This involves using acetone to dissolve the edges of the crack and then fusing them back together.

To repair cracked acrylic with acetone, you must clean the surface to remove any dirt or dust. Then, sand the edges of the crack to roughen them up and promote adhesion. 

Now apply acetone to a cotton swab or cloth and use it to dissolve the edges of the cracks. You need to apply pressure to the edges of the crack to close it and allow the dissolved material to fuse together.

Use a hair dryer or heat lamp to speed up the drying process and improve the bonding. Finally, sand the repair to restore the smooth surface of the acrylic and polish it to restore its shine.

Caution: Be very careful while using acetone, as it’s a flammable substance and can be irritating if inhaled. Work in a well-ventilated area, and use protective gear.

How To Repair Cracked Canvas Painting?

The solution to fixing cracked acrylic painting on canvas is to remove affected paint segments from your canvas and give it a fresh look; I recommend you first moist the cracked area to soften the paint, then sand it to remove the affected part. Now apply a new layer of paint to replace the missing part of the painting.


How to fix cracked paint?

Fixing cracked paint consists of three main steps. First, you need to remove the affected parts of the painting, then apply primer followed by a fresh paint coating.

Can you fix the cracked acrylic paint?

Yes, you can fix cracked acrylic paint by sanding, refilling, and repainting the affected spots on the surface. You may also use acetone to soften the cracked corners. 

Why is my acrylic paint cracking when it dries?

Your acrylic paint may crack due to several reasons, including irregular drying of upper and lower layers, thick coating, non-rigid surface, moisture, or using low-grade paint.

How do you fill cracks in paint?

You can fill cracks in paint by sanding the affected area and refilling it with primer and new paint coating using a palette knife or fine-haired brush. 

Can I paint over cracked acrylic paint?

Yes, you can paint over cracked acrylic paint if you have fixed those cracks and smoothened the surface.

Final Words

You can find several tutorials and blogs on how to fix cracked acrylic paint, but It is a simple process that can be done with basic tools and materials, making it a cost-effective solution for restoring the appearance of damaged paint.

Whether you’re a professional or a DIY lover, taking the time to fix a crack in acrylic paint can help prolong the life of your painted surfaces and keep them looking great for years to come.

Please comment with your queries, suggestions, and appreciation in the box below. 

Thank You! 

Jose Scott

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