If the area that needs to be repainted is not large, it only takes a few minutes with a touch-up pen. If it is repainted, it will take a long time, because repainting requires sanding, spraying primer, and original paint. There are also varnishes, etc., which take a long time. If you go to a 4S shop, it will take half a day or a day, and if you go to a repair shop, it will also take three or four hours.
Let’s take a common situation as an example. A car is parked in a community and a large hole is cut in the car door. In traditional touch-up painting, whether you drive to a 4S shop or a repair shop, it will take one to two days. After the repair is completed, you will be asked not to wash the car or do beauty treatments first. The injured area can be restored immediately within 40 minutes to 2 hours. At the same time, the car can be washed and beautified immediately. This is a quick touch up.
Repair process:
1. Determine the repair scope: Check the damaged area carefully. If the damage exceeds one-third of the part, excessive repair should be performed.
2. Determine the degree of damage: If it is a shallow scratch, there is no need to apply putty. You can directly polish until there are no traces and then proceed to the next step. If it is a deep scratch or a small pit, you need to apply putty. If it is deformed, sheet metal processing is required.
3. Construction protection: Prepare relevant materials and tools, and tape parts other than damaged parts, especially the corners, to prevent unnecessary damage during polishing. .
4. Bottom layer treatment: Clean the sediment around the damaged area. If the scratch is deep, you need to apply putty. When applying putty, first use P240 sandpaper to roughen the damaged area to improve the adhesion of the putty. Focus on taking an appropriate amount of putty and curing agent according to the size of the damage. Stir evenly. When scraping, first squeeze out the pits or scars, then hold the scraper at 45 degrees to flatten the damaged area. The damaged area should be slightly higher than the surface of the component, and bake with an iodine tungsten lamp. Increase drying speed. After drying, sand it smooth with P320 sandpaper and then smooth it with P800 sandpaper. Then spray the primer.
5. Masking and degreasing: First use an air gun to blow away the water and dust in the gaps between the parts, then use masking paper to carefully cover the parts other than the sprayed parts, and then use paper towels dipped in a little degreaser to spray the parts. Wipe the parts once, then use a dust removal cloth and an air gun to carefully wipe the spray parts before spraying with paint.
6. Spray paint: Dilute the prepared paint, stir thoroughly and filter. Pay attention to the control range when spraying. Adjust the air pressure to 2 KPa for dry spraying. Use a special dust removal cloth to wipe it once after spraying. , first cover the primer and gradually transition outward until there is no color difference.
7. Spray varnish: After confirming that the paint has no color difference and is completely dry, you can spray varnish. Pour an appropriate amount of varnish according to the size of the spraying area and add the initiator. Spray air pressure is 2-2.5KPa. The first pass is light. Spray, let it sit for 1-2 minutes according to the temperature, and then spray the second time. When spraying the second time, the gun should be compacted and the gun should be sprayed slowly and overlapping two molecules at a time. After spraying, check with the light to see if there is any leakage, especially At the corners, once the edges are confirmed to be correct, they can be processed.
8. Barge treatment: Carry out barge treatment after the varnish is sprayed. Mix the bright oil and barge water in proportion and spray on the joint. The air pressure should be slightly higher during spraying. When transitioning from the newly painted area to the original paint, the paint should not be sprayed too thickly and the transition should be even.
9. Baking: Connect the power of the UV baking lamp before spraying, and place the baking lamp according to the spraying area to facilitate operation. Turn on the baking lamp 3 minutes after spraying the varnish, because the varnish takes 5 minutes to flow. Level and rest time. The baking lamp needs 1-2 minutes to preheat. After preheating, you can bake. Wear a special goggles or glasses when baking. Grill the edges first and then the middle to increase the speed. Bake the second time. When doing one pass, keep a distance away to prevent gloss loss caused by drying too quickly. Move the baking lamp 20-25cm away from the parts evenly and do not stop at the same place during baking to prevent the temperature from being too high. Bake a small area for 7-9 seconds to dry, and a large area can be dried. It takes a relatively long time. You can use your hands on the masking paper to feel whether the varnish is dry, and then touch the paint surface with your hands. If it feels smooth, it means it is dry. Otherwise, you need to go over it again.
10. Grinding and polishing: Quick repair process: after quick drying, polishing, baking and drying, remove the masking paper, use 2000# cosmetic sandpaper to polish the paint surface to matte and remove dirty spots, tears, and polish When polishing, the interface should be lightly ground. After polishing, use a high-speed polisher and special abrasive to polish. After polishing, use medium-coarse abrasive for initial polishing and then fine-polishing with microcrystalline abrasive until it reaches full gloss. The interface should be polished. If the light tossing is just right, it will be exposed after passing the interface. If it is not thrown in place, it will not light up. After cleaning the side seams and body of the components, the car can be delivered.