How to Remove Rust from Knives with Baking Soda (and Other Natural Remedies)

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How to Remove Rust from Knives with Baking Soda - Photo of Baking Soda

Do you have a favorite knife that’s been sitting in your kitchen drawer for years? You love the way it cuts without much effort, so you don’t want to buy another one. But what about all of those rust spots? Is there a natural way to remove them and restore your blade back to its former glory? 

Rust doesn’t have to be the end for your knife. Luckily there are many natural remedies you can use at home without spending money on expensive products to remove rust from your favorite knives (and without harsh chemicals). In this article, we’ll cover how to remove rust from knives with baking soda, vinegar, and other natural solutions.

When you know how to clean a rusty knife and how to get the rust off knives, you don’t need to buy new knives all the time.

How to Remove Rust from Knives with Baking Soda

Baking soda can easily remove rust from your kitchen knives naturally, as long as the rust is fairly light. Some of the other options covered later may be effective against heavier rust, but you may want to try baking soda first.

You’ll need a bowl, baking soda, water, and a toothbrush to restore the metal back to its original condition.

Start by cleaning the knife to make sure all the dirt and loose particles are removed. You can simply wipe it down with a cloth if it’s fairly clean, to begin with.

Arm & Hammer Baking Soda, 16 oz (3 Pack)Arm & Hammer Baking Soda

Put a generous amount of baking soda in a bowl and add just enough water for it to form a thick paste. Spread the paste onto all of the rusty parts of your knife. Allow it to sit on your knife for at least an hour before scrubbing it off with an old toothbrush or another scratch-free tool.

If the rust isn’t coming off with the toothbrush, you can try steel wool or a wire brush, but be careful that you don’t scratch the metal of the knife’s blade.

Related: How to Clean Oven Racks Naturally

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How to Get Rust Off Knives with Vinegar

The acetic acid in white vinegar destroys rust. Other types of vinegar may cause stains, so avoid using them.

Vinegar is another solution you can use to remove rust from knives, cutlery, and scissors safely. All you need is white vinegar, a bowl or cup, and a clean cloth.

Submerge the knife in vinegar and let it sit for about five minutes. If it soaks too long, the vinegar can damage the metal.

After five minutes, pull the knife out, rinse it with water, and then dry it with a clean cloth. This should remove the rust. If it doesn’t, move on to one of the other methods.

Related: Home Remedies for Limescale (Natural and Effective)

Lucy's Family Owned - Natural Distilled White Vinegar, 1 Gallon (128 oz) - 5% Acidity Lucy’s Family Owned – Natural Distilled White Vinegar

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How to Remove Rust from Knives with Lemon and Salt

If vinegar doesn’t work, try using lemon juice and salt. The citric acid in the lemon can help remove rust, while salt acts as an abrasive to rub away any stubborn rust spots.

All you need is a lemon, salt, and a clean cloth.

Simply slice a lemon in half and sprinkle salt on the rust spots. Squeeze some lemon juice onto the knife and then rub your knife with the lemon halves and rinds until all of the rust is removed. Then rinse with clean water and dry the blade.

Related: How to Clean Copper Mugs

How to Get Rust Off of Knives with a Potato

You might be surprised to hear that potatoes are extremely effective at removing rust. The oxalic acid found naturally in potatoes is used in many cleaning products, but in this case, we’ll simply use the potato.

All you need is a potato, some salt, and a clean cloth. The salt is optional but will be helpful.

There are two different ways to do this. This first option is to simply stick the knife in the potato so the rust spots are covered (and touching the potato), and let the knife sit for a few hours.

Morton Iodized Table Salt, 26 Oz, pack of 2Morton Iodized Table Salt

The other option is to slice your potato in half and rub the inside of the potato on all of the rust spots. Optionally, you can also sprinkle some salt onto the knife to give you some extra scrubbing power.

Wipe off any excess rust with a clean cloth, then rinse under water to remove dirt and bits of the potato.

Related: How to Wash Fruit and Vegetables

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How to Remove Rust from Knives with an Onion

An onion is another natural option for removing rust from your knives. All you need is an onion and a clean cloth to hold the knife.

Simply place the knife inside of the onion and let it sit for about an hour. The rust should come off with very little effort. If the rust doesn’t come off, use the knife to cut the onion and rub the knife against the onion as much as possible. As you repeat this cutting motion a few times, the rust should come right off.

How to Get Rust Off Knives - Photo or a Rusty Knife

What is Rust?

Rust is iron oxide. Iron oxidizes overtime when it comes into contact with air and water. The primary cause of rusting is excessive moisture.

It occurs naturally on objects made of iron or steel, but can also form on aluminum, chromium, zinc, copper, silver, gold, and several other metals.

Rust is a common problem for metal tools because it will spread throughout the entire surface until it eats through to the unprotected metal underneath.

Why Do Knives Rust?

Knives rust because they are made of metal. A knife is at risk of developing rust if it has water on the blade, is left wet or damp, or comes into contact with saltwater.

Certain foods can also cause rust or corrosion. For example, acidic tomatoes can quickly form a corrosive layer of rust on the blade. Onions and other vegetables have similar properties that can corrode steel knives over time due to their sulfur content.

How to Clean Kitchen Knives and Prevent Rust

The best way to prevent your kitchen knives from rusting is by ensuring you always dry them off and store them in a dry place. After cutting or slicing, make sure to wipe the blades clean and then let them dry thoroughly before putting them away. When storing, avoid putting your knives into a sheath that will not allow for airflow.

Getting rusty doesn’t mean your knife is no longer useful. As you’ve seen in this article, there are several easy ways to deal with small amounts of rust. If you properly care for your knives, they can last up to ten years or more with proper use and storage.

Related: How to Clean Stove Grates

Frequently Asked Questions

Here are answers to some common questions about how to clean a rusty knife or how to remove rust from knives.

Is Rust Dangerous to Your Health?

No, rust itself is not dangerous to your health. It’s only when the metal beneath the rust (i.e. iron) begins to come into contact with oxygen that it becomes dangerous because then you can get sick from eating or breathing in iron oxide particles.

Can You Use a Knife with Rust on It?

Yes, you can still safely use the knife as long as the rust is not extreme. The rust is unsightly and it comes off easiest if you get to it quickly, but that doesn’t mean that you can’t use a knife that has some rust.

Can a Rusty Knife Be Restored?

Yes! Unless the rust is extreme, it can be removed with any of the five natural methods covered in this article (baking soda, vinegar, lemon, potato, onion). If the knife has been rusty for years, it may be too late for restoration.

Why Use Natural Treatments?

Harsh chemical cleaners can damage your knives permanently, and they’re also potentially hazardous to your health. Thankfully, there are several natural solutions that work, so you can avoid harsh products.

What is the Fastest Way to Remove Rust from Metal?

White vinegar is one of the fastest options. After letting the knife soak in vinegar for about five minutes, the rust should come off on its own or by lightly rubbing it with a cloth.

How Do You Remove Rust Without Scrubbing?

White vinegar will often do the trick. Let the knife or metal object soak for about five minutes and then rinse it off with water. Light amounts of rust should come off with no scrubbing.

Final Thoughts on How to Remove Rust from Knives

A small amount of rust on your kitchen knives, cutlery, or scissors isn’t anything to be concerned about, but you should try to remove it once it appears. The long the rust sits and the heavier the rust becomes, the harder it is to get off. In this article, we’ve shown how to remove rust from knives with baking soda, vinegar, and other natural and chemical-free methods. Now you know how to clean a rusty knife and how to get the rust off knives, so you should be able to significantly extend the life of your knives.