Rust removal and rust repair tips
"A little RUSTic charm"
Rust is metal's version of cancer.
One it takes hold, rust will continue eating into more and more of the metal. Rust requires oxygen and water to form.
The paint on your car bodywork protects the underlying metal from rust by preventing moisture and oxygen reaching the metal. All it takes is a chip in the paint for the rust to start taking hold.
Initially rust will bubble up the surface but gradually it will eat deeper and deeper into the metal. The earlier rust is caught the easier it is to repair.
Any rust spots will need to be thoroughly treated.
1) Sand the area down until you get back to bare metal with no trace of rust visible. It's always a wise precaution to sand a little wider than the obvious rust damage. It's vital to sand the surface smooth because any imperfections will show up when it is painted.
For larger areas of rust you may need to cut out the rust patch and weld in a new plate.
2) Coat the entire area with a rust inhibitor. This doubles up as an undercoat/key for the next stages. There are many brands of rust treatments on the market and generally they are equally good. Remember, these products are not rust killers or rust removers, they simply prevent further rust formation in sound metal.
3) Fill the depression left after sanding with filler. Smooth the filler and when dry sand it off. (Shallow depressions may only need a thicker coat of paint or some high build primer.)
4) Cover the area with paint as outlined in our stone chip repair guide. Finish off with some cutting paste and a clear coat.
If the rust damage is more serious, such as on wings and the bottoms of doors, the only real option is to cut away the rusty metal and weld in a new panel.
For larger areas of rust on car doors it is often easier and fairly cheap to replace them from a breakers yard and simply repaint them. Front fenders are also easy to replace and paint.
Larger areas of rust on the rear fenders and other structural areas will need a new panel welding in to properly sort it.
Take care to cut all the rust away and then coat the area with a rust inhibitor to stop further rusting whilst you are working on the area.
Rust prevention is much easier than rust repair. The most obvious way to guard against surface rust is to apply a wax coating every 6 months. See our article on wax and polish for more information on this.
Another line of defense is corrosion inhibitors. These are usually sprayed under the car and behind panels. TorqueCars recommends applying rust inhibitor spray in several thin coats. Take care to avoid clogging up the drain holes in the bottom of the panels.
Use a blunt piece of wire to check and clear each drain hole to ensure that it is not blocked. The last thing you want to do is to allow water to collect inside the panel or door.
Rainwater leaking into the cabin can be a sign of rust, usually they are just caused by broken rubber seals but the area should be fully investigated for rust. Pay particular attention to rust around the windscreen. We have known cars that have gone in for a simple windscreen replacement only to require extensive work to the frames due to rust.
If you require any more information on the treatment of rust or general care of your car please join us in our friendly forum where our resident enthusiasts will be able to provide tips and advice.
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