Why Does Spray Paint Crackle?

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Last updated: June 2, 2023

Discover What Makes Your Spray Paint to Crackle and Learn How to Deal with Spray Paint Crackling

Why does spray paint crackle?

There’s nothing more frustrating than prepping and spraying an item, only to discover crackling across the surface after a few days or weeks. It is even worse when you don’t know the cause.

Crackling is a bane to both DIYers and professional painters and can affect even the most planned projects. So, why does spray paint crackle? And how can I prevent spray paint crackling?

I explain my experience with spray paint crackling and how I managed to work around it. I will also discuss what causes spray paint to crackle, how to fix it, and what you can do to prevent it in future projects.

Why Does Spray Paint Crackle?

The main reason spray paint crackles is excessive heat or humidity. When the weather is too cold, or you have a lot of moisture in the air, paint takes longer to dry, which affects how it adheres to the surface. Also, if you apply the second coat before the first coat is completely dry, the paint might crackle.

Why Does Spray Paint Crackle?

If you notice crackles on your workpiece after painting, then there are a few things that might be the cause. Let’s take a closer look at each of these and more reasons why spray paint crackles.

1. Temperature Is Too High Or Low

If you apply spray paint when the weather is too hot or cold, it can crackle. This is because, in such conditions, it’s difficult to get a dry surface. For instance, if it’s too hot outside, the solvent will evaporate, causing the paint to clump together and crack. 

Likewise, the paint will not adhere well if the temperature is too cold. Also, the paint will dry from the outside in. In this case, as the top layer dries, it will shrink and pull on the wetter base coat, which ultimately results in crackling.

The best way to avoid these is to check the weather before starting your project. You don’t want to use a spray paint outside the temperature it’s meant to be applied. So, ensure you have the perfect temperature and humidity in your workspace. 

Generally, anything between 50 to 89 degrees Fahrenheit is recommended for temperature, while humidity should not exceed 85 percent.

2. Applying Excess Paint

Not applying spray paint correctly or using too much paint can also cause crackling. 

If you apply paint too thickly, the top layer will dry first, while the base paint will still be wet. This causes the surface to crackle and leads to an uneven application as the base paint moves.

To prevent this, use multiple thin layers instead of a few heavy coats. While this may take more time, it ensures you get the desired finish. 

To get a lighter coat, hold the can 12-18 inches away from the surface and spray back and forth quickly. 

Also, allow the first layer to dry completely before you apply the next one. This is also important to prevent crackling. It doesn’t matter whether you used a primer, don’t apply another layer until the previous one has probably dried.

2. Using Poor Quality Paint

Using poor-quality paint can also cause crackling. Many ridiculously low-priced products do not contain enough binder or pigment. Such paints are more likely to peel or crackle over time. 

Note: Pigment gives the paint its color while the binder holds the pigment together. 

To avoid this, always choose high-quality spray paints from reputable brands. They might cost a little more upfront, but you will get a lot more value and save yourself from future repairs.

In addition to choosing the right product, avoid mixing different paint products, especially when they don’t go well together. For example, mixing an oil-based paint with latex or painting one over the other. Both paints dry and move differently. 

In addition to the recommendations above, make sure to read the instructions on the label before using the spray paint. Also, take care of dirt and moisture on the surface before you start.

How Can Spray Paint Crack?

Spray paint can crack when there’s a paint reaction or if you don’t allow the base coat to dry properly before applying the second coat.

For instance, if you mix different paints or apply one over the other, a reaction might occur instantly, or over time after the paint has dried, resulting in a crack on the surface. A possible explanation is that since the paints don’t have the same composition, they dry and move differently.

Also, applying a second layer of paint before the first one has completely dried may cause the second layer to dry faster. When you have a base coat that dries at a slower pace than the top layer, it can pull the top coat and shrink the surface.

In both cases, a crackled effect will be left on the surface; sometimes, this will resemble a spider web.

When cracking occurs, the general approach is to completely sand the surface or substrate and reapply the paint, giving each coat enough time to cure.

Depending on the nature of your project, you may need to apply a paint barrier or primer in between to protect the base coat from color damage or make it adhere better.

What is Spray Paint Crackle Effect?

Spray paint crackle is not always accidental. Sometimes, it can be a deliberate attempt by hobbyists or crafters to add an artistic effect to an item. This may be the case when spray painting glass or ceramic. Crackling looks good on these surfaces. 

Why does spray paint crackle?

To achieve a spray paint crackle effect, you need to create the right surface for the paint to bond. 

  • Start by cleaning the surface to remove all dirt and grime.

  • If you want the crackle effect to look more professional, you can sand and prime the surface as well, but this is not a requirement. 

  • Next, apply a thin layer of Vaseline on the surface before you apply the base coat. 

  • To create a crackle effect on a surface, you will need to apply a thick base coat instead of multiple light layers, as is done in regular spray painting. 

  • Now, allow the paint to dry to a reasonable amount, but not completely, so the crackles can form.

Alternatively, you can apply the base coat in a light color and then, on top of that, add a second coat that has a different color. This will make the crackle effect more visible.

Remember to apply Vaseline on the surface before you begin painting. This helps you to achieve a more pronounced crackle effect as the coatings dry by creating a barrier to separate them. 

Finally, sometimes one cannot be too careful enough. If you want to achieve a crackle effect by all means, then consider using a special crackle effect paint. A good example is the Montana Cans Crackle Spray Paint

Why Does Spray Paint Crack on the Second Coating?

If you’re applying spray paint in layers, there’s a chance the surface will crackle after you add the second coat or subsequent coatings. This usually happens when you don’t allow the first layer to dry. If you don’t allow enough time for the paint to dry properly, you will end up applying a second coat on wet paint.

What will happen is that the second coat will dry much faster than the first coat. This is understandable since the cooling effect on the layers is not the same. So, the paint beneath the surface will not dry properly, while the paint on top dries completely in a short time.

After some time, the wet paint will move as it cures, pulling away the top layer and causing it to crackle.

To prevent this, always allow previous coats to dry completely before you apply another one.

Why is Spray Paint Cracking While Drying?

If you find spray paint cracking while drying, it can only mean two things. Either the paint was applied too thickly, or you didn’t allow the base coat to dry before applying a second layer. You can prevent this by making sure the base coat is thin and giving it enough time to dry before adding another layer on top.

In addition, painting when the weather is wet or too cold causes the paint not to dry quickly and affects how it adheres to the surface.

Why is spray paint cracking after clear coat?

Spray paint cracking after clear coat is likely to occur when you overspray the surface. In other words, applying too much paint beneath the clear coat will give the paint an uneven texture, leading to a crackled effect.

A paint reaction can also be responsible. For instance, if you apply latex over an oil-based base, you will run into some issues.

How to Fix Spray Paint Crackle

Restoring a cracked spray paint is not an impossible task. In fact, it’s one of the simplest tasks if you know what to do. Follow the steps below to fix spray paint crackle.

1. Identify the cause

Don’t be in a hurry to start repainting your project. Start by identifying what caused the problem. If you applied too much paint, then it’s likely the top layer dried faster than the base coat. Likewise, if you don’t prepare the surface properly, the paint will not adhere well, and that could lead to cracking.

In any case, wait for the paint to dry before you do anything!

2. Sand the Surface

Once you identify the cause of the problem, it’s time to fix it. If the problem is due to the paint being too thick, you can sand down the crackled area. For poorly adhered paint, strip off the paint and start all over again.

Sanding should be done gently with a fine grit sandpaper so as not to ruin the underlying surface. Move the paper in small circular motions, reaching into small holes and crevasses. Do this until the lines of cracks disappear.

Once you’re done, brush off the dust and debris created by the sanding. Then wipe the surface with a damp rag or paper towel and allow it to dry.

3. Prime the surface

The next step is to prime the surface. Priming helps to fill voids and ensure the finish is even. It also creates a base for the paint to stick better.

Paint a thin layer of primer of your choice over the surface. In most cases, we’ve found latex primer to be good, but you can use a primer of your choice as long as it goes well with your spray paint. After applying the primer, give it some time to dry; we recommend waiting at least 6 hours.

You can apply a second layer of primer if you feel the first one didn’t cover the surface well. Wait for the primer to dry. After drying, the primer should have set steadily; if not, you can lightly sand it again.

Apply new coats of spray paint

Once the primer is fully dry, apply a new layer of paint. This is the base coat!

Allow it to dry completely, then apply a second coat. Do this as many times as you want, depending on the number of coats you wish to use. It’s best to apply several thin layers of paint instead of one or a few thick coats.

While spraying, hold the canister at least 12 inches away from the workpiece.

The exact time to wait for each coat depends on the paint, but in most cases, it will take 4 hours or more. Always check the label before you start.

Spray Paint Cracking on different materials – Why & How to avoid/fix it?

One of the main reasons spray paint is so popular is that it can be used on various types of material, including metal, plastic, wood, and glass. However, each of these materials has its own rules that must be followed to achieve the desired results.

In the following sections, we will look at why spray paint crackle on different surfaces and how to fix/avoid it.

How to Prevent Spray Paint from Cracking on Metal

Most spray painting jobs are usually done on metal surfaces. However, metal is often prone to extreme cold, which prevents paint from adhering well.

One way to resolve this is to warm up the metal surface with a simple heater. This is highly recommended, especially if you don’t plan on priming the surface; otherwise, the paint will stick. You may not need a heater if you’re working outside and the weather is warm.

Before you paint, take time to prepare the metal piece. Make sure the surface is smooth and primed (especially if there’s rust on it). This is essential for the paint to go as smoothly and evenly as possible. Priming also creates a barrier between the surface and the paint, so there’s no cracking as the paint dries.

To properly prepare the metal surface, clean with a wet cloth to remove dirt and grease. Then sand it down and apply a primer. Use a spray paint specifically designed for metals, and make sure to use thin layers of paint.

Finally, allow the previous coat to dry completely before applying additional coats.

How to Prevent Spray Paint from Cracking on Wood

Due to its rigidity, wood is more likely to crack than many other surfaces. This is also fuelled by the fact that it contains moisture, which makes it peel and expand/contract more than paint when there’s a change in temperature and humidity.

The best way to prevent cracking on when spray painting wood is to prepare the surface thoroughly beforehand. Make sure the wood is smooth and free of splinters. In most cases, you will need to sand and prime it.

Sanding and priming ensure the wood is smooth and ready to receive spray paint. This is important for both bare and previously painted wood. Priming minimizes porosity in bare wood, while sanding previous paint ensures the new finish adheres perfectly.

It’s also important to ensure the wood surface is dry and the temperature in the space is warm enough. Ideally, you should use a spray paint specifically designed for wood. All these are required to prevent crackling on wood.

How to Prevent Spray Paint from Cracking on Plastic

Spray paint tends to crackle on plastic when the surface is not so smooth or has a subtle grain. This causes the paint to settle unevenly, which may cause cracks to form as the paint dries. So, the type of plastic you’re painting does matter. You will always get the best results with spray paint on a smooth surface.

It’s also important to pay attention to the type of spray paint you’re using and ensure it’s compatible with the plastic material. Sometimes, chemicals in the plastic can react with the paint, leading to degradation and crackling. To prevent this, test a small section with the spray paint before you commit to painting the entire plastic.

The shape of plastic is also a contributing factor. Some plastic items may have complex shapes or be multi-surfaced with a lot of curves. Such pieces are usually difficult to spray paint because you need to paint from several angles.

In such a situation, it’s easy to layer excess paint in some areas and cause the paint to crackle. One way to prevent this is to wait long enough in-between coats, especially when spraying two different angles that overlap. Don’t try to spray different angles or curves at the same time in an attempt to cover the entire piece.

Also, ensure the previous layer is fully dry before you add a new one.

Finally, before painting plastic, always sand and degrease the surface to remove oil. This is because having oil on plastic will prevent paint from adhering perfectly. Next, you want to prime the surface and wait until it dries before you start painting.

How to Prevent Spray Paint from Cracking on Glass

Glass is very smooth, and that makes it easy to spray paint. It’s not even necessary to use a primer. In most cases, several light coats of paint will give you a smooth finish.

Crackling usually occurs when you use too much paint at a go, especially on a base coat or several layers. This causes the top layer to dry faster than the base coat or layers underneath. To avoid this, use less paint in each coat and allow complete drying in between.

Similar to plastic, avoid applying too much paint at a spot in an attempt to cover every angle or curve at once. Instead, when you come across angles that seem to overlap, spray one angle at a time, then allow it to fully dry before you spray the other angle(s).

Finally, to get the desired results, choose a spray paint specifically designed for glass objects.

FAQs – Why Does Spray Paint Crackle

Why is rustoleum spray paint cracking?

Rust-Oleum spray paint can crackle if you don’t allow the first coat to dry properly before applying a second coat. It doesn’t matter whether you use a primer or a topcoat. To stop your Rust-Oleum paint from cracking, use the techniques described above. Prepare the surface before spraying and allow enough time in-between coats.

Can you paint over cracked paint?

No, don’t paint over a cracked paint job. Doing so will only worsen the problem because the added layer will also crack and peel off in the end. To avoid this, first, remove the cracked paint before you apply a new layer of paint. Also, allow each coat to dry completely before you add another one.

Can you redo crackle paint?

Yes, you can. Simply remove or sand down all the cracked paint to the base coat. Then prep the surface and apply a smooth paint. For more details, follow the steps described above to fix cracked paint.

Why did my spray paint crinkle?

The main cause of wrinkling in spray paint is using too much paint in a single coat instead of multiple thin layers. This is more common with oil-based products. Other conditions that can cause spray to wrinkle are painting over a contaminated surface, using incompatible paint products, and not allowing the first coat to dry thoroughly.

Why is my spray paint spider webbing?

You are more likely to experience spider webbing in spray paint if there’s a paint reaction or if you apply a second coat before the base coat has fully dried. In reality, webbing is the same thing as crackling. In this case, hairline cracks are left on the workpiece. These cracks resemble a spider web.

Content Summary – Why does spray paint Crackle

Spray paint crackle can be quite easy to fix. But it’s best to avoid it, so you don’t have to go through the hassle of repainting your project. Remember, your paint job is only as good as the surface preparation. So, take time to prepare the workpiece before layering it with paint. And allow each coat to fully dry before you apply the next one.

Now that you know what causes spray paint to crackle and how to prevent it, you’re all set to take on your next painting project with confidence. Make sure to use high-quality spray paint, and remember to read the instructions on the product label before you begin. Don’t rush the job; take as much time as necessary, so you can achieve the desired finish.

Let us know if you have any more questions about cracking in spray paint. Until then, happy spraying!

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