How to Clean Rust Off Steel

Using Household Products

Use a potato and dish soap on light rust. Cut a potato in half with a knife. Drizzle dish soap onto the cut end of the potato. Rub away rust by firmly scouring rusted areas with the soapy potato. This method can be messy; work over a sink or outside for easier cleanup. The potato-soap approach to rust removal is most effective on small, light rust stains that are easily accessible.

Use lemon and salt to remove light rust. Scrub away loose rust flakes with a wire bristle brush. Cut a lemon or lime in half with a knife. Sprinkle a generous amount of salt onto rusty areas. Squeeze the juice from your cut lemon or lime over the salt. Wait 30 minutes to an hour, then scrub at the rust with the rind of the lemon or lime. Rinse the metal with water and then dry it with a towel. It may take several applications of salt and lemon/lime juice before the rust is removed. Repeat this process as necessary. This method is suitable for light rust stains, especially those on kitchen knives. Use caution when cleaning knives to prevent accidental cuts.

Get rid of mild rust with baking soda. Rinse the rusted metal with water and shake it dry over your sink or outside. Sprinkle baking soda onto areas with rust. The soda will stick to the still damp metal. Leave the soda for about an hour, then scour rust away with steel wool, a scouring pad, or a metal bristle brush. Rinse the item with water and dry it with a towel. This technique is most useful for light rust, rust rings, rusty baking pans, and other kinds of thin metal that have developed rust. While scrubbing, use firm, steady pressure. It may take some time before the rust comes free. If rust remains after rinsing, repeat this process until the rust is completely removed.

Erase heavy rust with a white vinegar bath. Fill a bucket with enough vinegar to completely submerge the rusty metal. Remove loose flakes of rust by brushing afflicted areas with a wire bristle brush or steel wool. Soak the item in vinegar overnight, then rinse the item in water and dry it with a towel. Larger rusty items may not fit in a bucket. In these situations, saturate rags in white vinegar and wrap these around rusty areas. Leave the rags on overnight, then brush, rinse, and dry the item as per usual. This rust removal technique works well for severe rust, especially on steel tools. Vinegar will not harm the surface or integrity of steel. The longer you leave items in vinegar, the more effective it will be. Soak heavily rusted items for longer periods of time. Repeat this process as necessary to remove stubborn rust.

Remove rust with an application of citric acid. Follow the directions on the citric acid to mix it with hot water to form a cleaning solution. Immerse your rusted steel item in the solution for 8 to 10 hours or overnight. Avoid soaking items for more than 24 hours. After soaking, use a stiff or wire bristle brush to remove any leftover flakes. Rinse the item in water and dry it with a towel. Citric acid can be purchased at most grocery and health stores. You can usually find it in the canning section. In some cases, citric acid may go by the name “sour salt.” Most citric acid products are prepared by adding 2 or 3 tbsp (30 to 44 ml) of acid to a moderate amount of hot water in a bucket. Citric acid will remove paint from items. It is safe for use on steel, and works well for removing heavy rust.

Using a Rust Converter

Protect your lungs, skin, and eyes. Although rust converter is a relatively mild rust neutralizer, it can cause lung, skin, and eye irritation. Wear protective goggles and rubber gloves when using converter. Only apply converter in areas with good airflow to prevent the buildup of harmful fumes. Rust converter can be purchased at most hardware stores or home centers. Converters are generally safe for use on iron and steel.

Remove oil, grease, and loose rust. Use a stiff or wire bristle brush to remove loose rust flakes. Grease and oil will interfere with rust converters. Use a degreaser or soapy water to clean away dirtiness, then dry the metal with a towel.

Apply converter to rust with a brush or roller. Open your rust converter or add a moderate amount to a plastic paint tray. Dip a paintbrush in the converter and paint rusty surfaces. Larger surfaces can be covered more quickly by applying converter with a roller. Some converters may have a spray applicator. If your steel is galvanized, most rust converters will only be suitable for severely rusted areas. Converter will not adhere to galvanized surfaces.

Wait until the converter dries and add a second coat, if necessary. Most kinds of rust converters will dry in about 20 minutes. For the converter to fully cure, it generally takes about 24 hours. Apply a second coat of converter after it has fully dried, especially for heavy rusting. A second coat will convert any missed rust. After the converter has dried, you don't need to rinse or do anything more to the rust. The converter will stick to it, neutralizing it and preventing it from spreading.

Paint over dried converter if desired. Paint can help prevent rust and corrosion from spreading to other areas of the steel. Additionally, paint can hide the black, inert substance created and left behind by the converter. Only use paints formulated for steel.

Sanding Away Rust

Wear safety googles, gloves, and a dust mask when sanding. Small rust or metal particles may become airborne while sanding away rust. Protect your eyes with safety goggles and your skin with work gloves. Wear a dust mask to prevent yourself from breathing in particles.

Sand away rust with sandpaper. The heavier the rust, the coarser the sandpaper you use will need to be. Choose sandpaper or sander in the 50-grit range to remove heavy rust. When the rust is removed, finish sanding with an extra fine grit paper, like a 400-grit wet/dry polishing sandpaper. Steel wool can also be used similarly to sandpaper to remove rust. Start with a coarse wool, like one with a rating of 3. Finish with an extra fine wool, like one rated 000 or 0000. Steel that has a finish may be damaged by sanding. After removing the rust, you may need to re-seal or paint the metal to prevent future corrosion.

Use a power sander or a grinder for severe rust. Large surfaces or extensive rust can be most easily removed with a power sander or grinder. When sanding in this fashion, keep your sander in motion to prevent gouging or uneven sanding in the metal. Narrow or difficult to reach areas can be targeted with a mouse sander or oscillating tool. Grinding wheels, when used improperly, can deface the surface of your rusted steel. Always keep the sander in motion at all times.

Rinse and dry the metal. Residue from sanding will likely cover the surface of your metal. Rinse it in cool water and dry the metal with a towel. Inspect the metal for rust when dry. If rust remains, repeat this process until it is removed.

Using Chemical Rust Removers

Work in areas with good airflow and wear protective gear. Chemical rust removers usually contain a strong acid. This acid can burn your bare skin and gives off harmful fumes. Always work with chemicals in a well-ventilated area. Wear rubber gloves, safety googles, a suitable air mask, and clothing that covers your entire body.

Submerge small items in chemicals. Fully immerse rusted steel in the rust removing chemicals according to the remover’s label directions. In most cases, soaking for 8 hours or overnight will allow enough time for the chemical to remove most rust. Some brands may require varying lengths of time to work most effectively. To ensure the best results, always follow the label directions. Light rust won't need to be soaked for as long as heavy rust. Soak lightly rusted metal for 1 to 3 hours.

Use gel rust removers for large objects. Larger objects may be impossible to submerge in the chemicals. For these items, choose a gel based chemical rust remover. Paint the remover onto rusted surfaces with a paintbrush or applicator and wait the time indicated on the label.

Scrape off rust and inspect the metal. Use a putty knife or a similar tool to scrape off rust from the surface of the metal. Wipe away remaining chemicals or rust with a suitable rag dampened with water. With the rust and chemicals removed, you should be able to determine the amount of rust remaining, if any.

Repeat chemical applications as necessary. When treating a heavily rusted object, expect to apply chemicals several times before the rust is fully removed. When the rust is gone, rinse the metal in cool water and then dry it with a towel.