Knife Restoration 101: How To Get Rust Off Knives 

 Last Update September 18, 2023

By Jenny Zhang

Home / Guides / Knife Restoration 101: How To Get Rust Off Knives

There's nothing quite like the feeling of a sharp, gleaming knife in your hand as you prepare a delicious meal. However, as time goes on, even the best knives can fall victim to the relentless march of rust. Rust not only dulls your blades but also poses health risks as it can contaminate your food. If you've ever pondered the solution to banishing that troublesome rust and bringing your knives back to their original splendor, you're in the right spot.

But fear not. In this guide, we will rescue your knives from the clutches of rust and bring back their sharp, gleaming beauty. So, if you're tired of struggling with rusty knives or simply want to ensure the longevity of your kitchen tools, read on.

6 Methods To Clean Rust Off Of Knife

Removing Rust With Baking Soda

The sodium bicarbonate found in baking soda is useful in removing rust spots. It naturally has an abrasive texture but also neutralizes the acid compounds found in rust. This greatly facilitates the removal of rust stains when using the baking soda method.

  1. Prepare a baking soda paste by mixing a small quantity of water and baking soda in a small bowl.
  2. Spread a generous layer of this thick paste onto the knife.
  3. Utilize a soft cloth or a small brush to massage the paste into the areas with rust gently. You can use steel wool to rub the baking soda onto the knife blade if necessary. However, steel wool can scratch the steel, so be careful and avoid using it on light rust stains.
  4. Wipe the entire blade clean, wash with dish soap, and dry fully with a towel before storing.

Removing Rust With A Whetstone Rust Eraser

Rust erasers are made by combining rubber with silicone carbide. They are a useful addition to any kitchen because they are small, easy to use, and remove rust spots from knife blades with minimal damage to the metal.

  1. Prep the rust eraser by soaking it in water for 5 minutes.
  2. Rub the rust eraser over the rusted areas, scrubbing in the same direction as the grain of the blade of your knife.
  3. If the rust eraser block dries out while you scrub, set it in the water again momentarily.
  4. Wipe the knife blade clean, wash with dish soap, rinse, and dry fully before storing.

Removing Rust Using Citric Acid

Lemon juice is a concentrated form of citric acid and works great at cleaning rusty knives. It's particularly effective if used in conjunction with the baking soda method!

  1. When making the baking soda paste, use lemon juice instead of water.
  2. Alternatively, cut a lemon in half and sprinkle it with baking soda.
  3. Rub either the baking soda paste or the cut lemon on the rusty knife.
  4. Wash the knife with dish soap, rinse, and dry with a towel for storing.

Removing Rust Using Vegetables

This method is surprising in its effectiveness! The potato method takes advantage of the natural oxalic acid found in potatoes to eat away at the rust spots. Onions also serve the same purpose, using sulphonic acid.

  1. Stab the rusted blade of your knife into either a potato or onion. Ensure that the vegetable covers all of the rust stains.
  2. Leave the knife in the vegetable overnight.
  3. Remove the knife the following day, scrub with dish soap and a soft sponge, rinse, and dry fully before storing.

Removing Rust Using Vinegar

White vinegar contains acetic acid to clean rust spots off of a knife.

  1. Submerge the knife blade in white vinegar. This is perhaps best done by filling a tall cup with vinegar and setting the knife inside it or using a tray.
  2. Let the knife soak in the vinegar for at least 5 minutes.
  3. Rub down the knife with a clean rag, wash using dish soap, and dry fully before storing.

Remove Rust Using Lemon

Lemon juice is another acidic option if you prefer a more natural approach.

  1. Squeeze fresh lemon juice into a container. If you're using bottled lemon juice, pour it into a small bowl. You can also cut a whole lemon in half and squeeze the juice onto the rusted areas.
  2. Soak a soft cloth or sponge in the lemon juice, or apply it directly to the rusty sections of the knife by squeezing it.
  3. Take a cloth or sponge and delicately scrub the rusted areas. The natural acidity of the lemon juice will begin to dissolve the rust. You can apply a small quantity of baking soda to the affected areas for more stubborn rust. Baking soda serves as a gentle abrasive, further aiding the rust-removal process. Keep scrubbing gently until the rust is gone.
  4. Thoroughly rinse the knife under a stream of running water to eliminate any traces of lemon juice or baking soda residue. Examine the knife closely to confirm if all the rust has been eradicated. If not, it might be necessary to repeat the process.
  5. After removing the rust, dry the knife with a clean, dry cloth to prevent any remaining moisture from promoting future rust.

Methods To Avoid Using To Remove Rust

It is frequently recommended to use various harsh chemicals, such as WD-40 or mineral oil, to remove rust from knife blades. Although these cleaning solutions are effective, they are highly toxic if ingested. Never use them to remove rust stains from kitchen knives or any knives you intend to use to prepare food.

What Causes Rust Stains On Knives?

A chemical reaction between the iron in the blade of your knife and the oxygen and moisture in the air around it causes rust stains. This process results in the formation of reddish-orange iron oxide, commonly known as rust!


Certain blade steels exhibit a higher susceptibility to rust compared to others. Knives are generally crafted from two main categories of metals: carbon steel and stainless steel.

Carbon Steel - Carbon steel knives are made from steel reinforced with additional carbon. Frequently, other metal alloys are added. These blades are very strong and durable, but the higher carbon content makes them more prone to corrosion.

Stainless Steel - Stainless steel knives contain chromium, creating a strong oxide layer on the blade's surface. This prevents oxidation and rust, which is why this type of steel is called "stainless." However, even stainless steel blades can rust if not maintained properly!


Water is a key component in the rusting process. When knives are exposed to moisture, whether from washing, humidity in the air, or contact with wet ingredients during food preparation, it can initiate a rusting reaction.

Acids and Salts

Certain foods, particularly those with acidic or salty properties, can accelerate the corrosion process. For instance, cutting tomatoes or citrus fruits with a high-carbon knife and leaving them unwashed can lead to rust stains due to the acidic juices promoting oxidation.

Washing in a Dishwasher

Dishwashers expose knives to a harsh environment with high heat and strong detergents. This can strip away protective coatings and contribute to rust formation, especially on knives with wooden handles.

Improper Storage

Storing knives in a humid or damp environment, such as a closed drawer, a damp kitchen towel, or a sink filled with water, can create the perfect conditions for rust to develop.

Maintaining Knives To Prevent Future Rust Stains

Even the highest-quality kitchen knife can become rusty if not maintained properly. The following maintenance steps will help prevent rust from developing on your knives.

Never use the dishwasher

Using dishwashers to clean knives not only causes them to lose their edge but it also creates an environment where hot moisture sits on the knife for an extended period of time.

Keep knives clean and dry

Always wipe down a knife with a damp cloth after using, and then dry it thoroughly and immediately. Neither food residue nor water should be allowed to sit on the knife blade!

Jenny passionately advocates a holistic and natural approach to health and well-being. She has a Bachelor of Science degree and years of working in food sciences, specializing in organic & natural products. She is committed to helping others embrace a balanced, natural lifestyle that fosters well-being. Jenny believes that a harmonious balance between nutrition, fitness, and mindfulness is the key to unlocking the full potential of one’s well-being.

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