No.56: Setting Up the Coating Work

service paint voyager service ct thinner

7 Practical Guidelines for Paint Workers 

Article 2: Preparations for Painting Work 

Key Notes 

For painting work preparation, three essentials are crucial: selecting the optimal paint, determining painting procedures, and quality control. Special emphasis is on environmental consideration and weather resistance, necessitating the choice of appropriate painting methods and strict management of work quality. 

Preparations for Painting Work 

1. Three Essentials of Preparation

The preparation for painting work entails meeting these three essential criteria: 

   ① Selection of a suitable painting system (Good Materials): Choosing the optimal paint. 

   ② Adoption of appropriate painting specifications (Good Design): Determining the procedure and method of painting. 

   ③ Sufficient work management (Good Management): Quality control of the entire process. 

Let’s consider the painting of outdoor metal products. There are multiple methods for painting systems and specifications, which are presented in a table. Methods (a), (b), and (c) all pass the test items specified by customers, so the painter selects the most suitable method from these. For instance, if there is a line for baking liquid paint, the (a) method of electrostatically painting with solvent-based paints is usually chosen. For environmental compatibility, the (b) method using powder coatings or the (c) method for cathodic electrodeposition are considered for corrosion resistance. Also, when considering painting costs, the one-coat finish of powder coating (b) is an effective choice. Note that the degreasing of bare steel and chemical conversion coating are the same for all methods. 

These methods are evaluated from these perspectives, and the results are summarized in a table. To simplify, the evaluations for methods (a), (b), and (c) are equivalent to 6 points each. 

2. Good Management

When prioritizing environmental considerations, method (b) is often chosen, but it raises concerns about long-term corrosion resistance. To address this issue, paint manufacturers are focusing on improving powder coatings. For instance, there is a special powder coating designed so that epoxy resin aligns towards the base material and fluororesin towards the surface after baking. Preventing temperature unevenness during the baking process is crucial to achieve this precise resin orientation. Hence, “Good Management” becomes very important. It means clearly identifying crucial points in the entire painting process and managing them appropriately. 

In this case, for outdoor metal products, the performance regarding weather resistance – like degradation and rusting of the coating, changes in gloss and color – is particularly important. If the product passes salt spray and accelerated weathering tests, its “design quality” can be considered assured. Therefore, proper management of the other crucial quality element, “work quality,” is required in painting operations. During the pre-shipment quality inspection process, careful attention is paid to the specified test items to check the quality.