Repair Minor Rust on a Car
When bare metal comes into contact with the oxygen in everyday air, the resulting chemical reaction (called oxidation) creates rust, which eats away the metal in your car. If you've got a little elbow grease to spare, this guide will give you some tips for removing rust from your car to prevent further damage.
Steps
- Wash the area around the rust spot. This ensures that there is no additional grease, dirt, or grit to further damage your car's finish. Use soap to break up grease that is not water soluble.
- Dry the area to be repaired.
- With masking tape, tape off the area surrounding the rust. This will help prevent debris from getting onto your existing paint, and also helps protect the paint from overzealous sanding.
- With a strip of dry sandpaper or a sanding sponge, rub the rusted area. If you're using sandpaper, push only with your index finger. If you're using a sanding sponge, or block, then only use a corner. Use moderate and controlled pressure. The goal is to remove the rust, not damage the metal underneath.
- Keep sanding until all of the rust is gone. Don't sand away metal or paint unless it is necessary to remove the rust.
- When the rust has been removed, blow away any excess, and wipe off with a cloth dampened with denatured alcohol to remove little bits of rust, paint, dust, sweat, blood, etc.
- Examine the area where the rust once was. If you still see rust, repeat sanding and wiping until the rust is gone. If you wind up with uneven spots or even holes in your metal, consider applying auto body putty to even out the area. Let the putty dry. Sand until smooth and the entire area is even.
- Remove the tape and wipe off with a cloth dampened with denatured alcohol again.
- Coat the sanded area with primer. Exposed bare metal will only rust again, so don't skip this step or you'll be back where you started in a few weeks.
- Once the primer dries, your repair is complete. Now you're ready to move onto the next rusty spot on your car, or begin painting the car so your repair can truly look "as good as new".
Tips
- This guide is for minor rust repairs. Don't use lots of force sanding, and don't use an air-powered sander or rough grades of sandpaper unless the rust is really bad. If it is that bad, you might consider saving time and just replacing body parts with some from a junkyard.
- Consider the quality of your tools. If you care what the finished product looks like, expensive body putty is well worth the price. If you're not going to bother painting it once the damaging rust is stopped, then cheap primer will probably get you by for awhile.
- Rust occurs because air is in contact with bare metal. Rain and salt make a bad situation worse. When you see rust, it is a good sign that the protective layer of paint has been compromised. You might consider having your car repainted if you're noticing rust pop up in multiple places.
- If rust has eaten through the metal then a more expensive and extensive repair is needed to remove the rust.
Warnings
- Wear eye protection while sanding. Rust flakes hurt, and can damage more than just your paint.
- Make sure the area has adequate ventilation when priming or applying putty. Insects, dust and weather conditions can be avoided by parking your car inside for the work, but you don't want to be overcome by fumes.
- Wear a mask or respirator. If the car is an older model, be aware that older paints may have lead in them. Lead dust is dangerous to breathe, and using power or pneumatic tools to sand the car may increase the amount of lead dust.
Things You'll Need
- Soap & Cloths; for washing at least part of your car.
- Masking Tape;
- Sandpaper or a sanding sponge; possibly with multiple grades of roughness. Most sanding sponges at your hardware store come with two grades.
- Primer;
- Auto Body Paste; (optional)
- Paint; for after you've repaired the rust, (optional but recommended)
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