Sanding the surface of a car before applying primer and paint is the most important part of a good paint job. Even the most expensive paint won't look good if proper sanding steps weren't taken when preparing the surface of the car. Sanding a car involves several stages of sanding to get the surface straight, smooth and ready for paint to be applied. Sanding serves multiple purposes, including removing old paint, smoothing scratches and creating a surface for paint to adhere. With the right tools, anyone can follow step-by-step auto sanding instructions for great results.
Things You'll Need
- Sanding block
- Dual-action sander
- 80-grit sandpaper
- 120-grit sandpaper
- 220-grit sandpaper
- 380-grit sandpaper
Sand old paint and primer off of a car using a dual-action sander and 80-grit sandpaper. This can be used to sand the car down to the bare metal without digging into the metal surface. A dual-action sander oscillates in a way that sands the surface without gouging the metal. Hand sanding at this stage is possible, but it won't come out as smooth and can take hours rather than the 30 minutes it takes to sand a car with the sander.
Use 120-grit sandpaper to sand down any body filler used on the car's surface. Place the sandpaper on a sanding block. Keep the block horizontal and move it at an angle to make X shaped patterns while sanding. Always lead each stroke with the long edges of the block, not the short ends. Using the short ends and moving the block left and right can cause a ditch in the filler that may not be noticed until the final paint has dried.
Cover the sanding block in 220-grit sandpaper to sand the primer coat after it has dried. Use the same techniques as when sanding with the previous grit. The primer should be gently sanded to only knock down the very top layer. Sanding too much can make the metal show through and make a low spot in the primer.
Go over the entire car using 380-grit sandpaper to get the smoothest finish before applying the paint. This can be done using your hand or a sanding block. Be careful to only sand gently and never sand the edges or corners of the car for more than a second or two. Sandpaper can easily dig too deep on the edges and cause the underlying layers to show through.
- Photo Credit Stockbyte/Stockbyte/Getty Images
How to Block Sand a Car
One of the steps involved in body work preparation before a car is painted is a system called "block sanding".This is an...
How to Prep a Car for a New Paint Job
Preparation of an auto body before painting is critical to a good paint job. It's been said that 90 percent of the...
How to Paint a Car Step-by-Step
Many individuals these days are deciding to do a lot of the repairs to their vehicles themselves in order to save some...
How to Paint Kitchen Cabinets Without Sanding or Stripping
If you want to refinish your kitchen cabinets with a stain and clear finish, you have to strip them first, but you...
Auto Body Sanding Tips
Sanding a vehicle before painting is very important. In fact, professional painters often state that the sanding process is far more important...