How to Remove and Repair Auto Body Rust

a closeup of vehicle rust
  • 2-10 hours
  • Intermediate
  • 60-150
What You'll Need
Hand held grinder
P150 grit sanding wheel
P150 grit sandpaper
Metal grinding wheel
Painters tape
Auto body primer

Auto body rust repair is essential because rust is not only unsightly on a vehicle, but it can cause permanent damage to the bodywork. This is why taking care of the rust is vital. It’s not a difficult job, even for those with no real auto body experience. You will need some tools but if you need to perform regular auto body repair on your vehicles, you should have these on hand.

Step 1- Preparing the Surface

The first stage in auto body rust repair is to prepare the surface. To do this, you need to make it smooth. For this, you’ll need a portable hand held electric grinder that’s fitted with a sanding wheel. Before using it, put on safety goggles and gloves.

To use it effectively, apply it where the paint starts to drop away around the rusted area. If you feel it, it will feel rough under your fingertips. Use the grinding wheel lightly on this area until you can feel the difference between the painted areas and those where you’ve removed the paint. You should also use it on the rusted area. Unless the rust is very light, this won’t remove all of it.

Step 2 - Removing Rust

To take out most of the rust, you’ll still use the hand held grinder, but with a metal grinding wheel attached. Be careful using this. Go slowly and keep stopping to check your work. If there is any small pitting or marks in the metal, the metal grinding wheel will smooth them out.

Step 3 - Sandpaper

Once you’re happy with your work, set aside the hand grinder and pick up some P150 grit sandpaper. This is a more important stage than you think, since it gives a final smoothness to the area, and also lets you feather the edges of the paint, which will give a much better finish when you repaint the metal.

Take your time over this stage and be very thorough, as the eventual result of your auto body rust repair will depend on it.

Step 4 - Primer

Before you use the primer, tape off the area you’ll be painting with painter’s tape. Make sure you use this, rather than regular masking tape, as it won’t leave marks or damage the finish.

Apply a thin coat of primer. Buy good primer, not the cheapest you can find, and make sure you just apply it thinly. You’ll achieve the best finish for your auto body rust repair by taking the time to do a total of 3 thin coats of primer. Allow 10 minutes between each coat for the primer to dry, then apply the next coat. However, when the last coat is on, leave the vehicle overnight before you proceed.

Step 5 - Paint

For the paint, apply in thin coats. Use at least 3 coats with 2 hours time to dry between each one. Allow to dry overnight, then wash and wax the car to complete the auto body rust repair.