Auto vor dem Lackieren abschleifen und polieren how-to-sanding-and-polishing-a-car-before painting

How to Repair Car Paint at Home?

A highly polished body makes an impression! But what if cracks, scratches and dents spoil the picture? When thorough cleaning and polishing no longer help, it's time to sand and repaint the car's paintwork. However, this requires a certain amount of sensitivity and careful work. With the tips from Fastplus Abrasives, you can do it yourself - and your car will look good again!

  • Difficulty level: medium
  • Duration: one to two days plus paint curing time
  • Tools: Sanding block or random orbital sander, dry and wet sandpaper in different grits, adhesive tape, car paint, polish, sponge, soft cloth, cleaning agent, gloves, respiratory protection

Step 1: Preparation - which sandpaper for car paint?


Before you can sand the car paint, you have to get the necessary utensils ready. Depending on the work you want to do, you will need different grit sandpaper to sand car paint, you should choose a particularly fine paper with 240 to 320 grit. If all of the paint has to be removed, first do a rough sanding with 40 to 80 grit. This can be followed by an intermediate sanding with 80 to 120 grit. And then you use the finest sandpaper again for the final sanding. For a particularly smooth result, use wet sandpaper.

So that the sanding dust cannot settle back into the paintwork and you grind in scratches, you should always remove it thoroughly. To do this, tap out the sandpaper and vacuum away the dust. If you do not sand by hand but with an eccentric sander, you should ideally choose a device with an integrated dust extractor. Also, put on a respirator to keep dust out of your airways.

Step 2: Thoroughly clean the car paint


Before the actual sanding process, it is important to clean the autobody properly again. You should definitely remove residues of silicone, wax, fats, and oils, otherwise the new paint will not adhere well. Since the care products used there often contain exactly these substances, you should not drive to the car wash for cleaning. Rather use a damp cloth and detergent or the pressure washer to clean your car. If necessary, a silicone remover is also helpful. Since these agents can be very aggressive, you should wear your respiratory protection when using them.

Step 3: Roughly sand the body

Schleifen und Vorbereiten eines Autos vor dem Befüllen-sanding-and-prepare-a-car-roughly-before-car-filling

If you want to sand off the entire paintwork, the coarse sanding follows in the next step. Use the coarsest sandpaper and a sanding block or the eccentric sander. Generously sand down the car paint around the damaged area. This will give you a smoother transition between the old and new paint later.

If you sand away not only the clear coat and base coat but also the primer, you will need to renew them. If necessary, first apply primer and then filler before you fill the cracks and do the fine sanding. In this way, you prevent water from getting into the material via the filler and causing deep corrosion damage. Then the body has to dry well before you can continue with the next step. For a small area, a primer spray is sufficient instead of the primer.

Step 4: Fill cracks and dents

Risse und Beulen mit Spachtelmasse füllen und premieren-Fill cracks and dents by filler and premier

If you have previously applied primer and filler, it can be helpful to finely sand the surface again before repairing scratches and cracks in the paintwork. Then fill the imperfections in the paint with putty and smooth them out. The mass usually needs to dry for at least half an hour. Then you can work on the filled areas again with 80 or 120 sandpaper.



Step 5: Fine sanding – wet-sanding the car paint

Schleifen von Spachtelmasse und Premieren mit feinen Schleifscheiben oder Schleifpapieren - sanding car filler and premier with fine sanding discs or sandpapers

Finally, you dedicate yourself to the wet sanding of the car paint. To do this, the very fine-grain sandpaper must first be soaked in water. Then it is best to sand all the areas that you have already sanded with a suitable sanding block or by hand. In this way, you smooth out fine grooves and bumps that have arisen during dry sanding. The result is a smooth surface that you can now repaint.


Step 6: Renew car paint after sanding

ein Auto neu lackieren repaint a car

Before you apply a new layer of car paint, you must carefully mask off the areas with intact paint. Do not use masking tape for this, but special, particularly dense adhesive tape. This is the only way to ensure that there are no unsightly noses. If necessary, first apply the base coat as thinly as possible and let it dry. Then a new layer of clear coat follows. The drying time is usually at least two to three hours. Depending on the paint, however, full curing can take several weeks.

Step 7: Polish car paint properly

Polieren des Autolacks auf Hochglanz mit Polierpaste oder Wachs polishing car paint to high gloss with polishing compound or wax

Once the paint is completely dry, it's time to polish. But how do you polish a car properly? Experienced car fans can even polish small scratches on the car. After sanding and repainting, however, this is no longer necessary. The polish is then more of a radiant shine. You can polish car paint by hand using a polishing compound and a sponge or polishing cotton. Or you work with a polishing attachment for the drill. You just have to be careful not to apply too much pressure – otherwise, dents will easily appear in the paintwork.

Buy Fastplus Factory-Direct Abrasives

Want to purchase high-quality, factory-direct sanding discssanding sheet rolls, and film abrasive discs for automotive applications? Try Fastplus Abrasives today and place your orders online! 

Back to blog

Fastplus Sanding & Polishing Products

Fastplus Abrasives offer a full range of sanding and polishing products for car refinishing, wood, metal, plastic treatment, including sandpapers, sanding discs, sanding sheets, and rolls, foam sanding discs, buffing discs, pads, orbital sanders and accessories. Buy Fastplus sanding and polishing products online here.
1 of 20