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Preface: Whenever we take on the role of engineers, we bear the responsibility for the quality of the work. We are very responsible in our work, but there are some details that we have not mastered yet, which has led to problems with the quality of the project. The \"thickness of the coating and the issue of coating dilution\" discussed here are matters we need to pay attention to in coating management. During the painting process, attention should be paid to the thickness of the coating as well as the dilution of the paint. When painting on any type of substrate, some professional painters fail to realize the importance of using an appropriate application rate. This is because the paint can usually be applied at a higher application rate, while still achieving a consistent appearance, especially when the color of the primer is similar to the color being applied. For example, a painter might feel very good about being able to cover 12 m2 per liter of paint, while still achieving a good appearance. However, if 10 m2 per liter of paint is the application rate recommended by the manufacturer of that paint, then applying it at a rate of 12 m2 per liter will result in a dry film thickness that is only 80% of the recommended thickness. No matter how attractive its appearance may be, an excessively thin dry paint film can have an adverse effect on some of the key properties of the coating, and all of these properties affect the final quality of the project. The negative effects of applying too thin a layer of paint on its performance can manifest in various other ways; the impacts include: 1. The topcoat is affected, which in turn affects its crack resistance – the crack resistance of paint is directly related to the thickness of the dried paint film. It has poor coverage; the paint cannot fully cover the surface, so previous colors or patterns will show through the coating. Once the paint film is damaged due to weather conditions or cleaning, this problem becomes very apparent. It has poor washability, and the necessary cleaning to remove dirt or stains may damage part of the paint coating, especially on flat paint coatings. Therefore, the washability of thinner paint films is inferior to that of thicker paint films formed from the same coating. It has poor flow and leveling properties, and brush marks and roller marks are evident on the dried paint film. Applying a thick coat of paint can provide better flow and leveling properties. In terms of ultimate durability, under the same conditions, thin paint films are more susceptible to erosion than thick ones. The consistency of gloss; an overly thin paint film can impair this important property. 2. Impact on the primer The problems resulting from applying paint at a rate that does not comply with the specified standards affect not only the paint itself, but also the primer. This is because applying too much primer can also result in a thin paint film after drying, which in turn weakens its main properties. Regarding primers, the key properties affected by the application rate include crack resistance, coverage, mildew resistance, consistency in the gloss of the topcoat; and depending on the specific properties of the primer, stain resistance and corrosion resistance are also included. Therefore, take some time to measure your painted surface in order to calculate its area. Then estimate the amount of paint, colorant, and/or primer required to coat the entire area, in liters (kilograms). Regardless of whether you use spraying, rolling, or brushing to apply the coating, you should make every effort to apply a sufficient amount of coating to the surface. The recommended coating rate is determined by the condition of the surface to be coated (smoothness and porosity) as well as the specific coating used. For very rough exterior wall surfaces, such as rough cement surfaces, the area that can be coated per liter of paint is approximately 3.6 to 5 m2, while on smoother surfaces, such as properly cast concrete surfaces and smooth surfaces that have been pre-coated, 10 to 11 m2 can be covered per liter of paint. Whether you are undertaking indoor or outdoor projects, you must always apply paint and primer at the application rates recommended by the manufacturer. This results in a thicker, more protective paint film that lasts longer. All of this will make your customers unable to resist \"promoting\" the quality of your work everywhere. 3. Dilution is not a good method. Applying a certain amount of paint over an area larger than the recommended one results in a coating that is too thin, which can impair the key properties of the paint. Another way that results in an overly thin paint film is by diluting the paint. Thinning the paint is a concern, as it affects its coating and performance. For example, if latex paint is diluted with water before application and still applied at the recommended application rate, the coverage of the paint (measured in terms of the thickness of the dry film) will also decrease, as the dilution process reduces the volume solid content in the paint. This will also weaken the properties mentioned above regarding overly thin coating application. Dilution also disrupts the performance balance of the coating, especially the balance between flowability and leveling property on one hand, and anti-sagging property on the other. Thinning the paint causes it to run down vertical surfaces, prompting painters to apply less paint, which also results in a thin dry film. Therefore, unless it is necessary, do not dilute the paint (although it may be required to dilute it during spraying), and you should follow the paint manufacturer’s instructions for application.