Pocket putty is also called "filler putty" or defect ash. It is mainly used to fill in small defects (small defects) such as pinholes, pockmarks, and sand marks on the coating surface before the topcoat, so it is less labor-intensive to operate. , save material, save labor. However, scraping pockmark is a very meticulous work. Whether pockmark is scraped or not will directly affect the appearance quality of the top coat. Therefore, it is necessary to scrape pockmark well to ensure the appearance quality of the topcoat.
Scratches and pockmarks In the process of car painting, painters commonly call it "finding faults" or "finding pockmarks". For general automobiles such as trucks, ordinary passenger cars, etc., it is usually enough to find a numbness once. For mid-to-high-end cars and mid-to-high-end passenger cars, it is generally necessary to search for numbness twice in order to find and smooth all kinds of small defects on the surface. For high-end luxury cars and high-end luxury passenger cars, it is even necessary to find three or four times of pitting to make the flatness of the coating before the topcoat meet the quality requirements . .
(1) Ordinary automobile hemp eye scraping method
Ordinary cars, such as general trucks, buses, buses, etc., are carefully searched for pitting after the coating before the topcoat, such as the intermediate paint or the first topcoat, is dried and water-milled, so as to remove the surface of the paint film after water-grinding. Small defects such as small hemp pits, coarse sand marks, and orange pattern pits (small pits left by rough orange patterns that have not been fully ground) on the surface should be cleaned and scraped to make the surface meet the flatness required by the quality, and do a good job for spraying topcoat Get ready, lay the groundwork.
However, in the actual painting operation of scratching and looking for pockmarks in ordinary cars, most painters like to conduct a professional comprehensive search for pockmarks after the intermediate paint (or the first top coat ) is dried, and wait for the pockmarks to be found. After clean scraping and drying, use the intermediate paint (or top coat, because some of the sprayed topcoats are sprayed twice continuously wet-on-wet at one time, and some are sprayed with a topcoat first, and then the surface is cleaned with water for cleaning eyes. Finally, carefully spray the second topcoat) and carry out water milling together, and after the water milling is qualified, wash off the dirt, wipe off the water marks, and dry the water effectively, and then look for numbness on the surface of the part (main finish) . The method of operation is, after the intermediate paint or the top coat is dry, use quick-drying hemp eye putty to remove the rough sand grains or chaotic sand grains and groove marks on the surface of the paint film (due to the particle impurities on the surface Groove marks that are not cleaned but are pressed by emery cloth or water sandpaper), pinholes and other numbness problems, level and find along the light
Clean shave. When scraping pockmarked eyes, you should use a small scraper or ash knife, pick up a little pockmarked ash each time, and quickly apply 1-2 back and forth along the pockmarked area. Do not apply too much back and forth, because there are many pockmarked ash It is a nitro-type quick-drying putty. When it is scraped back and forth in one place too many times, it is easy to produce dry residue (putty scar). To prevent drying and scarring, and during the scraping process, the knife surface should be kept clean. If there is ash on the knife surface, it should be cleaned up, so as not to affect the quality and speed of scraping. When the gray surface in the scraping coating is dry, it can be melted and fully blended evenly, so as to prevent the formation of lumps in the dry skin mixed with ash, which will affect the quality of the scraping coating.
For example, scrape the hemp on the surface of the truck cab, because the main finishes of the cab are the exterior of the door, the lower part of the front windshield, the rear of the door and the surrounding parts of the upper roof, so these parts should be rubbed repeatedly along the light Find a clean shave. For the surface of other parts, it is enough to scrape off the obvious numbness. When scraping and painting passenger car pitting, focus The upper part) and the facades of the warehouses on both sides, etc., as long as the obvious defects are found and scraped.
(2) Scratch coating method for mid-range cars
Mid-range cars such as ordinary mid-range cars, mid-to-high-end buses, imported trucks, etc. For the scraping and coating of the pits of these cars, it should be scraped and painted in 2-3 times, so that all kinds of pits can be leveled and scraped. When looking for pockmarks for the first time, after the intermediate paint is dry, first level and scrape off the pinholes, pockmarks, groove marks, sand marks and other defects on the surface of the paint film in sequence, collect the residue, and dry for 1 - After 2 hours, smooth the surface with water, wipe off the water stains and effectively dry the water, and then perform the second search for numbness. When looking for the second numbness , since the surface is relatively smooth after water grinding, you should wipe the surface of the object with your hands while scraping the numbness (because the surface is smooth, some small numbness is not easy to see). Scrape and scrape cleanly with your hands, focusing on the main finishing parts of each car when scraping. Then perform a fine water mill (partial water mill) on the numb eye area. After the water mill is qualified, wipe off the water marks and effectively dry the water. Carry out the third time to find faults and pits. This time the focus should be on the main decorative parts of each car. It is necessary to repeatedly , and there must be no omissions. If you are looking for scratches on the surface of the car, you should carefully scrape along the light repeatedly from left to right until you find them all.
(3) Scratch coating method for high-end luxury cars
High-end luxury cars, such as high-end cars, high-end luxury buses, etc., usually need to be leveled 3-4 times or 4-5 times before the final topcoat is sprayed to achieve the smoothness required by the quality.
â‘ Scratch coating method for high-end car numbness
For high-end cars before the color change, the pockmarked dust is scraped, because the base layer of the original paint before the color change is relatively smooth, after the original paint has passed the water mill and dried, first look for the pockmarked dust in a comprehensive way, and then apply the new paint in the first coat The surface of the painted topcoat (the topcoat of a high-end car should usually be sprayed with 2-3 coats), the second leveling of the pitting dust is carried out, and the third leveling of the pitting dust is carried out after the water rubbing is dry , and it is necessary to level the pitting dust once during the leveling operation. More detailed than ever. After the third water grinding, spray the second topcoat. After the paint film is dry, perform the fourth leveling of pitting ash . After leveling and cleaning (after repeated inspections), spray the final topcoat. For the leveling of the pits in the fully refurbished high-end cars, usually the refurbished high-end cars need to be sprayed twice (two coats) of intermediate paint. Therefore, every time you spray a coat of intermediate paint, you need to look for numbness twice, that is, once after the intermediate coat is dry, and then again after full water grinding . In this way, four times of pitting leveling can be carried out by spraying two coats of intermediate paint. After four rounds of pitting leveling, the flatness of the base layer can basically meet the flatness of the quality requirements, and then after two rounds of leveling for pitting, It can fully meet the flatness required by the quality, and can be sprayed with a final finish.
â‘¡Scratch coating method for high-end luxury passenger cars
Scratch coating on high-end luxury passenger cars can usually be divided into four times. That is, after the intermediate paint is dry, search and scrape it comprehensively, search carefully after water grinding, search carefully after the first top coat, and search more carefully after water grinding . Such as spraying metal (aluminum powder paint, pearlescent paint, etc.) paint, you can find it once after the paint is dry in the gray, and then find it again after water grinding , and then after the metal paint colorant is sprayed and dried, find it once. Look for it again, and spray the metal color paste again , and you can use varnish to cover the light.
