The surface pretreatment process of the safe is very important in the entire powder coating process. It directly affects the coating quality, otherwise it will cause the coating to bubble and fall off easily.

Compared with sheet metal parts, chemical pretreatment methods can be used: degreasing → rust removal → cleaning → phosphating (or purification), etc.

For products with rust and thick surfaces, mechanical derusting methods such as sandblasting and shot blasting can be used. After mechanical derusting, the surface of the workpiece must be clean and free of scale.

Scrape putty: According to the degree of defects on the surface of the product workpiece, use conductive putty to scratch the defect, dry it thoroughly and smooth it with sandpaper, and then proceed to the next process.

Protection (also known as covering). If some parts of the workpiece are not required to be coated, they can be covered with protective glue before preheating to avoid spraying paint.

Warm up. Generally, preheating is not required. If a thicker coating is required, the workpiece can be preheated to 100-160°C, which can increase the thickness of the coating.

After these pretreatments, the safe workpiece can formally enter the next spraying process.