Crackle Paint, a Special Paint to Make Crackle Finish

Crackle paint is specially formulated so it will crack and form a crackle effect in the film layer when it is applied. This crackle paint is used to make an antique crackle finish, which was quite popular some time ago. Although less popular, the antique crackle finish still has fans today. Crackle paint is the main material that is used to make the cracked effect in the antique crackle finish. Today the crackle paint is available in the wood finishing material store, and you as a finishing person can find and choose the most suitable paint according to your needs. You just need the information and knowledge about the crackle paint and how to use it. Now, I want to share information about the crackle paint and how to use it.

white crackle paint

The types of cracked paint

Like other coatings, there are several types of crackle paint: water-based, NC, PU, melamine, etc. The NC base crackle paint is the most commonly used and available. The fact is the antique finishes are mostly developed with the NC finishing system since it is easy to use, fast-drying, and gives the best look. The water-based crackle paint is also quite popular because of the eco-friendly finish trend today. Both water-based and NC are quite simple and suitable to accommodate the complication of antique crackle finishing. 2-component crackle paints, such as PU or melamine, can be made, but they are rarely used due to their complexity in the application. The mixing process with the hardener, the pot life, and the application process will be complicated, making this paint rarely used.

• Clear crackle paint or clear crackle coating

According to the color, there are two types of crackle lacquer: clear and colored. Clear means the cracked paint is clear, or colorless. When applied, it can form cracks in the clear film layer. This paint is usually called clear crackle lacquer or clear top coat. This crack paint is applied over a sealer or base coat and forms cracks on the base coat or sealer layer. The cracks can be at the top layer only, or can go through its paint underneath, meaning the crackle paint is working to break the paint or coating underneath.

During the finishing process, this clear crack paint is usually further coated with a sealer or top coat. This crackle paint can be set to only produce a cracking effect on the surface above the underlying layer, or it can also be set so that the cracking effect shows through to the paint or base coat layer below.

• Colored crackle paint

Colored crackle paint is a cracking paint with some pigment inside. This cracking paint has the same color as a base coat or primer, but when applied, it creates a layer of paint with a cracking effect. This cracking paint is usually white or other base colors such as red, yellow, and black. Although the colored crackle paint can be tinted to create a specific color, it must be done carefully. The pigment addition to the paint will change the composition of the paint, which will potentially change the character of the paint. Too much paste in the paint will change the crackle pattern and make the effect uncontrolled.

Crackle paint finishing process

Various finishing techniques can be used to create the desired color and appearance for the crack finish. However, in general, the crackle finishing process is as follows:

• Stain or or paint application

Stain is needed to create the desired base color. When the crackling paint is applied, the base color will appear and create a contrast effect with the cracks. This stain can be a wood stain that creates a wood color or a base coat or primer coat to make a paint color.

• Sealer

To achieve a perfect crack effect, the crack paint must be applied to a flat, smooth surface; that is why you need sealer application in this step. If the crack paint is applied to a raw wood surface, the crack paint will be absorbed by the wood, and the crackle effect cannot be obtained. Usually you need 2 or more sealer applications to prepare the surface before the crackle paint application.

• Crackle paint application

After you get the smooth surface and enough film built, then you can apply the crackle paint. The application of the crack paint must be carried out with the correct and precise technique. Make sure you read the technical data sheet and how to use it. The crack pattern and size model depend on the paint type and are also influenced by application methods, such as paint layer thickness, thinning, and the drying process. Make sure you get the right paint, the right formula, and the right application technique to make the crackle effect you want.

• Sealer

Once the crack paint has been applied and the desired crack effect has been achieved, the next step is the application of a sealer. This sealer application protects the resulting crack effect and strengthens the existing crack effect. The sealer also makes the surface smooth and ready for glaze application.

• Glaze

A glaze application is necessary if an antique finish with a crack effect is desired. Glaze can be applied to fill in cracks and create a dirty or aged look. A glaze application is not needed if you want a clean crack effect without an old or dirty look.

• Top coat

Top coat is the final layer in the finishing process, protecting the color and appearance of the finish and at the same time forming the gloss of the finish.

Things to consider when applying crack paint

• Know the type of paint you're using

Before using paint, you must understand the type of paint you'll be using. Read the paint's technical data and specifications to ensure it's compatible with the finishing system you develop. The most commonly used crack paint is NC, or water-based, or other one-component paint, but sometimes you may have to make a crackle finish with PU since the finshing request.

PU or melamine crack paint is rarely found because the handling and application process is difficult and complicated. You will need to apply it correctly in detail. Do proper mixing, then do the right application; make sure you do the correct spray and create the right thickness and layer. 

The effect of crack paint is greatly influenced by the thickness of the paint layer and the dilution used. Ensure you apply it at the correct thickness and concentration to achieve the desired crack effect. Conduct several trials to familiarize yourself with the paint you'll be using and achieve the desired crack effect.

• Use compatible materials for the entire process

Consider the overall finishing system and use a crack paint that matches your finishing system. Crack finishes are generally created with an NC finishing system, but some crack finishes are created with a water-based or PU system. Some crack finishes are created using a combination of finishing systems. Make sure you do right finishing system to achieve a finish that is not only aesthetically pleasing but also strong and safe.

• Consider environmental conditions

The crack effect also is affected by the drying time. Sometimes the crack paints fail to achieve the desired effect due to an uncontrolled drying process, which is affected by the environmental conditions, the temperature, and humidity. Therefore, ensure you understand the conditions of your finishing room, especially the temperature and humidity. To avoid problems with paint cracking due to environmental conditions, you can provide an oven to control the temperature and humidity during application. You may adjust your paint by adding the special solvent to adjust the material drying, but it must be done carefully. 

• Application process

The resulting cracking effect depends on the thickness of the paint layer and the drying time. Adjust the thinning and number of layers of paint applied to achieve the desired cracking effect. The general rule for cracking paint is as follows: the thicker the paint and the longer it takes to dry, the larger the cracking effect will be. On the other side, the cracking effect will become smaller if the paint is thinner and dries quickly.

Several experiments can be conducted to find your desired cracking effect. Some variables to try are mixing ratio, paint layer and thickness, and the thinner used. It's important to understand that this cracking effect often can't be expected to be uniform in every area, as several factors will affect the results and cracking effect.

• Step panel

Every time you develop a new finish, it is always recommended to make a step panel to find the finishing process for the finish. The same thing with the cracking effect. The crackle effect pattern is very important since it is the focal point. The cracking effect will affect the appearance of the finish. Different cracking effects will create different-looking finishes, even if you use the same color, then controlling the crackle effect is a very important point in this finish. especially if you're creating a finish that uses the cracking effect as the focal point.

For this finishing process, you need to create a complete and detailed finishing process precisely with all necessary notes about the mixing ratio, spray application, and layer of coating in detail. You also need to check and record the humidity and the temperature of the finishing room. Then you can repeat the process in the finishing process on the product.

• Test the finishing performance

Cracked paint is a complex finish and often requires special tricks and methods to achieve the desired appearance. Therefore, before doing the process on a product, especially for big items and high-volume production, it is highly recommended to test the performance of the finishing you are working on. Make a panel according to your finishing system and do the necessary tests to make sure your finishing system is safe and can be followed to make the product.