If you have ever tried to paint over chalking paint, you know it can be a difficult task. The old paint seems to resist the new coat and leaves a powdery residue on the surface. To get a good finish, it is necessary to clean the chalking paint off first. But how do you do that without damaging the underlying surface?
What Is Paint Chalking?
Paint chalking is the result of paint that has weathered over time. The sun and weather break down the binder in the paint, causing it to become powdery. The good news is that this process doesn’t damage the underlying surface. It can protect it from further damage by acting as a barrier.
However, paint chalking makes it very difficult to apply new paint. The powdery residue will prevent the new paint from sticking and can even cause it to bubble and flake off. To get a good finish, it is necessary to clean the chalking paint off first.
Progression Of Chalking Paint
Paint chalking is a progressive process that happens over time.
- The first stage is when the paint starts to turn white. This is caused by the breakdown of the binder in the paint. At this stage, the paint is still relatively easy to work with.
- The second stage is when the paint turns powdery. This happens when the binder has completely broken down and the pigment is left behind. The powdery residue will make it difficult to apply new paint.
- The third stage is when the paint turns into a fine powder. This happens when the binder has completely evaporated. At this point, the paint is no longer able to protect the underlying surface.
Causes Of Chalking Paint To Occur
Paint chalking is caused by the breakdown of the binder in the paint. This is usually due to exposure to the sun and weather. Over time, the UV rays from the sun break down the binder, causing it to become powdery.
Here are some other factors that can cause paint chalking:
Thin paint Products
When the paint is too thin. This can happen if the paint is watered down or if it has a low-quality binder. A thin paint will not last as long and is more susceptible to chalking.
Wrong Paint Application
If the paint is not applied correctly, it can lead to chalking. This includes painting in direct sunlight or on a hot surface. Both of these can cause the paint to dry too quickly, leading to a chalky finish.
Unrestrained Heat Sources
If there is an unrestrained heat source near the paint, it can cause the paint to chalk. This includes things like grills, fireplaces, and heat lamps. The heat from these sources can cause the binder in the paint to break down, leading to a chalky finish.
Dirty Surfaces
If the surface is not cleaned properly before painting, it can cause the paint to chalk. This is because the dirt and debris will prevent the new paint from adhering properly.
Major Temperature Change
The paint can also chalk if there is a major temperature change. This includes painting in the winter and then exposing the paint to the hot summer sun. The sudden temperature change can cause the binder in the paint to break down, leading to a chalky finish.
Surfaces That Lack Primer
If the surface lacks primer, it can cause the paint to chalk. A primer provides a barrier between the paint and the surface. Without a primer, the paint is more likely to chalk.
Steps To Clean Chalking Paint
Even though paint chalking is progressive, it can be cleaned off. However, it is important to note that once the paint has chalked, it can no longer protect the underlying surface.
Here are some steps to clean chalking paint:
Rubbing The Surface
The first step is to rub the surface with a cloth. This will help remove any loose pigment. Be sure to use a gentle rubbing motion to avoid damaging the surface.
Remove Chalky Residue
Once the loose pigment has been removed, the next step is to remove the chalk residue. This can be done with a vacuum cleaner or by gently rubbing the surface with a damp rag or stiff brush to remove moderately chalked surfaces.
Remove Using Washing Powder
If the chalk residue is still present, you can try removing it with washing powder. Simply mix the powder with water to form a paste. Then apply the paste to the surface and scrub the surface gently.
Use Of Primer
Once the chalked surface is clean, you can apply a primer. This will provide a barrier between the paint and the surface. It will also help the new paint to adhere properly.
Applying New Paint
After the primer has been applied, you can then apply new paint to the surface to lighten the moderate chalk remains. Be sure to follow the manufacturer’s instructions for the best results.
Precautions To Prevent Chalking Paint
There are some precautions you can take to prevent paint chalking from defecting the painted surface:
Surface Should Be Cleaned
Make sure the excess surface powder is an appropriate cleaner before painting. This includes removing any dirt, dust, or debris. You should also make sure the surface is dry before painting.
Mixing Paint Properly
Be sure to mix the paint properly. This includes stirring the paint thoroughly. If the paint is not mixed properly, it can lead to chalking.
Use Of Weather Resistant Paint
If the surface will be exposed to the elements, be sure to use weather-resistant exterior paints. This type of paint is designed to withstand the elements and will not chalky powder as easily.
Remove Unstable Paint Films
If there is any unstable paint film on the surface of the paint, be sure to remove it before painting. This can be done by sanding or stripping the excessive chalking paint.
Don’t Use Interior Paint For Exterior
Don’t use interior walls paint for exterior surfaces. This is because exterior paint is designed to withstand the elements. By using this type of paint on an exterior surface, you can prevent chalking.
Let Us Help You!
Paint chalking is a progressive defect that can lead to the deterioration of the painted surface. However, it can be cleaned off with the proper steps. There are also some precautions you can take to prevent paint chalking from occurring. If you need help with painting your home or business, please contact our experts. We would be happy to help you!