Approximately 95% of the cars produced today have a painted body finished with a clear protective layer. This gives the shiny, shiny look that most drivers expect from a new car. This coating must be protected with wax and polished to preserve its appearance, but in some cases it is necessary to proceed with a water grinding to restore it to its original condition. Although a perfect professional polishing is achievable only in the workshop of a body shop and at high costs, water grinding can also be performed at home, albeit with a lot of work. All you need is a bucket, a rag, a cloth, two types of different grit sandpaper (typically 600 and 1500-2000), a low-speed polisher, a soap or car cleaner. and water. Follow the instructions in this tutorial to restore your car to the splendor of a show car.
Steps
Part 1 of 3: Wash and Wet the Car
Step 1. Wash the exterior of the car
Use water and a specific detergent or soap. Follow the instructions on the package carefully. Your goal is to remove all dirt and dust, so that the grinding and polishing process works directly on the clear coat.
Step 2. Dry the bodywork
When the machine is clean, gently wipe it dry with a cloth.
Step 3. Soak all the sandpaper
Leave it in clean water for at least an hour to prevent rough edges from scratching the paint layer.
Step 4. Wet the rag
Soak a rag in lightly soapy water. Use one cap of soap for every 4 liters of water or follow the instructions on the detergent package.
Part 2 of 3: Sand the Car
Step 1. Sand only a small section at a time
The width of the section depends on your preferences, but it is generally recommended not to exceed 0.1 m2. You have to remember which areas have already been treated and which ones still need to be sanded. In this way, the work becomes more manageable and organized; moreover, you are sure that every point of the body receives the right attention.
Step 2. Use an emery block or pad and not an electric grinder
In theory, you should rely on a rubber block that adapts to the shape of the various panels in the car.
Step 3. Start sanding
If you want to get great results, start with 600 grit sandpaper; later, switch to a higher grit, such as 1500 or 2000. Alternatively, use only the finer grit paper.
- Apply very little pressure.
- Hold the wet sandpaper in one hand and the soaked rag in the other; start grinding the bodywork with long and regular movements. Remember to respect the direction of the air flow when the car is in motion, for example from the front bumper towards the windshield.
- Sand with one hand and use the other to keep the surface moist with the rag.
- Make sure you do even work. Take a step back from time to time to observe your progress and check for any irregularities.
Step 4. Change direction
After sanding in a certain direction, proceed with movements perpendicular to it and slightly inclined. Remember to keep the body wet to avoid burning the clear coat.
Step 5. Switch to finer sandpaper
If you have chosen to start with the 600 grit, now is the time to start over with the finer, 1500 or 2000 grit.
Step 6. Make the body look dull when finished
With the polishing process, you will give it its original shine.
Part 3 of 3: Polish the Car
Step 1. Choose an abrasive paste
Experts recommend a simple and safe product for beginners, so ask the auto parts store clerk for advice. Be careful, because some pastes are more suitable for those with experience or the specific tools for this job.
Step 2. Start using the polisher
When you are satisfied with the look achieved with the sandpaper, you are ready to polish the vehicle. Remember to use a low rpm tool (about 1400 RPM).
- Do not keep the polishing pad resting on the same spot for more than a second or two.
- Polish in moderation. Do not insist too much on the scratches, to avoid burning the transparent layer. Keep moving the polisher and be careful not to overheat the surface.
Step 3. Prevent the pad from running dry
Otherwise, you will be forced to sand the area again or even have to reapply the clear coat to the surface.
Step 4. Protect the clear coat
This must be done regularly. Wash the car once a week and apply wax periodically to protect the bodywork and paint.
Advice
- Take your time. This is a long process, so you have to work calmly to avoid scratching the body or getting an uneven result.
- Use the highest quality and reliable products.
Warnings
- Be very careful, especially in the sanding phase. The clear coat on the body is only as thick as a sheet of paper.
- Wet grinding is a long job that dirties and wets both you and the surrounding area, but the result will pay off for the effort.
- Do not use a grinder machine.
