How to Repair Rust on a Car

As long as vehicle body panels are made from steel, they're going to rust.

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Introduction

Sooner or later, rust on cars is inevitable. However, if you deal with rust early, you can stop it from spreading and squeeze a few extra years out of your vehicle.

Rust repair isn’t hard, but it is time-consuming (mostly waiting for primer and paint to dry between steps). Plan to spend about $100 on supplies like sandpaper, primer, masking tape and poly sheeting, a tack rag, polishing compound and touch-up paint and clear coat. Choose a calm, overcast day and block out the full day to fix the most common rust spots on the hood and doors.

Project step-by-step (9)

Step 1

Go Shopping for Supplies

  • First, find the car manufacturer’s paint code.
    • Note: The paint code can be in a variety of places on the body, in the engine compartment or trunk, or other places. Use either of these online resources to find instructions on how to locate your paint code: automotivetouchup.com or duplicolor.com.
  • Buy automotive touch-up paint in pints and quarts to use in a spray gun, in aerosol cans, or in roller ball applicators.
    • Pro tip: Even if you know how to use a spray gun, mixing automotive paint with a reducer to match the temperature and humidity conditions can be mighty tricky. We don’t recommend it. Instead, buy aerosol cans for larger repairs and rollerball applicators to fix scratches.
    • Note: Most late-model vehicles were painted with base coat/clear coat paint. The base coat contains just the pigment and binding resins-the clear coat is just the gloss.
  • Buy equal amounts of both base coat and clear coat.
  • You’ll also need an epoxy self-etching primer to bite into the bare metal and a lacquer primer to hold the paint.
  • Buy 40-, 600- and 1,000-grit sandpaper, a sanding block, grease and wax remover, poly sheeting, painter’s tape, a tack rag and a microfiber cloth.

Step 2

Mask Off the Repair Area

  • Tape the leading edge of poly sheeting a few feet away from the repair so you’ll have room to blend the touch-up paint into the good areas.

Mask Off the Repair Area Car Repair 4Family Handyman