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How To Clean A Rusty Knife? Find Out Here

A rusty knife can be dangerous. The blade can slip and cause serious accidents. It can also be quite difficult to clean. The good news is that there are several things you can do to remove rust from a knife.

Wipe the surface with alcohol or rubbing alcohol. This will help prevent any further corrosion of the metal, but it won’t get rid of all the old rust.

You’ll need to use steel wool or another abrasive material on top of this step if you want to completely remove the rust.

Use baking soda which has an alkaline pH level. Then rinse off thoroughly with water. This should work well for most knives.

If your knife isn’t stainless steel then you may have to go through more steps than just using baking soda.

What is Rust?

Rust, or corrosion, occurs when metal reacts with oxygen in the air. When this happens, it forms an oxide layer on the surface of the metal.

This creates a protective coating which prevents further oxidation. However, if left untreated, the rust will continue to grow until eventually the entire piece becomes unusable.

Additionally, once the rust starts growing, it’s very hard to stop. If you don’t take action soon enough, the damage could spread throughout the whole item.

Why do knives rust?

Many old timers considered rust the sign of a knife’s quality, but a rusted knife is simply dangerous, useless and ugly.

Knives rust because there is always something wet around them. If you’re using a wooden cutting board, then this can happen naturally over time.

But most often, it happens after someone has used the same knife to slice raw meat, fish, vegetables etc., without washing it properly afterwards.

It also happens when people use the wrong type of soap or detergent which contains harsh chemicals like bleach. The main cause of rusting is due to oxidation of iron

Natural rust removal methods

There are many ways of removing the rust on your knives, but they all have their own pros and cons. Some work better than others depending on what type of metal your knife is made out of. Here’s how to get rid of it:

  • Salt water

Saltwater works great for cleaning most types of steel. You just need to soak the knife in salt water overnight or at least two hours.

This will help dissolve any remaining rust particles. Next morning wash away the excess salt by soaking the knife again in fresh water. Rinse thoroughly before drying.

  • Baking Soda

This method works best for knives with wooden handles, but it will work on any type of metal handle as well. Mix one part baking soda with two parts water in a bowl or container large enough to hold the entire knife.

Dip your knife into this mixture and let sit overnight. Rinse thoroughly before using. This should get rid of most of the rust. If not, repeat until all traces have been removed.

  • Vinegar Method

The vinegar method of removing rust involves soaking the rusted area in white vinegar for about 30 minutes, then scrubbing it with an old toothbrush or steel wool. Rinse off any remaining residue with water.

This process works well on small areas like your kitchen sink faucet. However, if you have large pieces of metal such as knives, this may not work very well because the acid will eat away at the metal itself.

  • Lemon and Salt

If your knife has been sitting in the dirt for some time, it may have picked up some soil particles on its surface. To get rid of this problem, simply rub lemon juice or salt into the area where the rust appears.

This will help loosen any loose particles stuck to the metal. Then wipe off with a cloth. Repeat as necessary until all traces of rust disappear.

  • Potato Method

The potato method involves soaking the knife in water with some baking soda added for about an hour or so. This will help loosen up any stuck-on dirt, but it won’t actually get rid of the rust itself.

You’ll need to use something like steel wool to scrub off the remaining bits of rust after this process has been completed.

  • White vinegar, apple vinegar

This is the most common method for removing rust. You need to use white vinegar in an amount of at least 1 part water to 3 parts vinegar.

This ratio will help prevent corrosion on your knives. If you don’t have enough vinegar or if you want to make sure all traces of rust are removed, add some baking soda as well.

  • Mineral oil

The first thing you should try when cleaning your knives with mineral oil is to soak them in it for at least 30 minutes.

This will help loosen the dirt stuck on the surface of the metal, making it easier to wipe off. You may need to repeat this process until all traces of rust have been removed.

  • Oxalic acid

The first thing I recommend for removing the most stubborn of rusted knives, oxalic acid. Oxalic acid will dissolve metal in contact with it.

You need to use this method on steel or stainless steel blades because they won’t react well to other acids like vinegar. If your knife has been exposed to salt water then you should rinse it off before using an acid solution.

  • Sulfenic acid

The first thing you should try if your knife has rusted on the edge or in any other place where it could hurt someone, is to use Sulfenic Acid.

This chemical will dissolve all types of metal rust including iron, steel, brass, copper, aluminum etc. You need to mix this with water before using it.

How rust dangerous?

It affects the appearance and strength of the metal. The more rust or corrosion, the weaker the steel becomes.

The first thing you need to know about knives, especially those used for cutting food, is how they react when exposed to moisture.


If the surface of your knife has been damaged by water or other liquids, it will not only make cleaning more challenging but could even lead to an accident if you use the knife without proper care.

If you think your knife needs attention, take it to a professional who knows what he’s doing. They will be able to tell whether your knife requires repair work or just a simple cleaning.

Carl Slay

Carl Slay

I have a fascination with the blade. Ma being a Chef and Pa owning a steel plant, it was inevitable some would say. From Chef knifes to Butterfly knives, to machete's - I know my blade! TheKnifeGuide was started as a means to serve enthusiasts like me in learning vital information. Whether it is for survival when indulging in the great outdoors or for your culinary needs, you've come to the right place!

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