How to Remove Rust from Knives (The EASY and FAST Guide!)
You’re cooking dinner for your family, and it’s now time to cut the meat. You pull out your favorite knife, but when you make the first slice… nothing happens!
You slice again and again but still get nothing. You press down really hard on the knife, but it still doesn’t cut through the meat. Frustration sets in as you pull out your trusty knife and stare at it.
You notice that there’s rust all over your knife—how do you remove rust from knives?
Why does stainless steel rust?
The chromium in stainless steel knives reacts with oxygen to form a thin layer of chromium oxide. This layer protects the knife from further rusting.
However, if this layer is damaged or the knife is exposed to moisture, it can start to rust.
Fortunately, stainless steel is one of the most rust-resistant metals in the world, but it can still rust.
When stainless steel is exposed to moisture and oxygen, it forms iron oxides—the same chemical reaction that causes iron to rust on a regular basis.
This happens because iron generally makes up a large amount of stainless steel in knives, which means it’s not immune to rusting.
How to remove rust from knives
Baking soda is a great way to remove rust from knives.
Baking soda is a strong chemical that reacts to iron and other minerals to form insoluble substances.
Baking soda is also very abrasive in terms of removing stains. When rust is exposed to baking soda, it results in the rust separating from the rest of the metal and dissolving in its alkaline solution.
To get started using baking soda:
- First, make a paste with water and baking soda. You can start with a 2:1 mixing ratio of baking soda to water. Scale up as much as you want if you have many knives that are rusty.
- Then, apply the paste to the metal. Spread the paste all over the metal, making sure that the rusty spots are completely covered up.
- Leave the baking soda paste on your knives (or other) for at least an hour.
- Grab some damp steel wool or a metal brush and place your knife firmly down where it won’t move. Scrub away at the metal on your knife. Be sure to focus most of your efforts on the areas with rust.
- Finally, rinse the baking soda paste off with water and immediately dry your knives.
If you have a knife that is starting to show signs of rust, you can use a rust eraser to remove the rust.
The rusty racer looks kind of like a small, grey, rectangular brick. It’s mainly made out of silicone carbide and stretchy plastic. This gives it a grinding and abrasive texture that can remove rust.
- Simply rub the eraser over the rusty area until the rust comes off. You may need to use some elbow grease to get rid of all of the rust.
- Once you have removed the rust, be sure to clean the knife with a soft cloth.
- You can also apply a light layer of oil to the knife to help prevent rust from forming in the future.
Lemon and salt
Lemon has acidic properties that can react and dissolve rust. It’s so powerful that you should be careful when using it to remove the rust from your knives.
A high amount of citric acid can cause damage to the metal if left in contact for an extensive amount of time.
- Grab some lemon juice and mix it with some coarse salt. You can also add a little bit of vinegar to make the solution stronger.
- Pour it onto the rusty areas of your knife and leave it there for 10 minutes.
- After no more than fifteen minutes, grab an abrasive sponge and put some elbow grease into scrubbing the blade.
- The rest should dissolve right off.
Be sure to completely rinse off all the citric acid from the lemon juice solution and dry it completely.
White vinegar can be used to remove rust from a knife blade.
The acidity of the vinegar makes it an effective solution for dissolving rust.
It also makes it easier to use an abrasive scrubber to remove the remainder of the rust on your knife.
Vinegar is mildly acidic with a pH of between 2 and 3. This means that when the acidic properties of vinegar make contact with iron oxide rust, it reacts to form salt and water. This is known as a neutralization reaction.
To clean a rusty stainless steel knife:
- Find a container in which you can fully submerge the rusty portion of your knife. It is a good idea to avoid any areas of the knife that are not made of metal. It may not react well with plastic and wood.
- Fill it up with white vinegar. You can also use apple cider vinegar.
- Mix that container with about 1/2 to 1 cup of table salt.
- Place your rusty knife (sharp edge down) into the solution, leaving out the handle so that it doesn’t damage it.
- Leave it in there for up to 12 hours depending on the severity of the rust.
- After the set time, take it out and grab a wool brush or wire sponge and start scrubbing away the rest.
- Optionally, once the rust is all gone, you can mix another solution made of baking soda and water to neutralize the acidity from the vinegar on the knife.
- Leave it in the baking soda solution for about 15 minutes and the acidity should be gone.
- Take out the knife, rinse it, wipe it down, and dry it off.
use a cloth dipped in white vinegar and dish soap. Alternatively, to clean a tub, soak the knife in the cleaner for one hour and then rinse it off. Vinegar is a great way to clean knife blades and grill grates.
Surprisingly enough, you can use potatoes to remove rust from your knives.
Potatoes contain a chemical called oxalic acid which is actually a key ingredient that is used in many cleaning products. It’s also a solution that is sold in paint stores to help get rid of paint stains.
Oxalic acid is able to dissolve rust. It works in similar ways to help vinegar remove rust. They are both acids. When oxalic acid makes contact with rust, this creates a chemical reaction that converts the rust into iron oxalate, which ends up dissolving away in the water.
But I bet you’re wondering how would you use potatoes then?
- Grab yourself a medium-sized potato and cut it in half.
- Cover the newly cut areas of both sides of the potato with a layer of salt.
- Use the sliced area of potato and scrub it onto the blade of the knife.
- Put some elbow grease into it and focus the scrubbing on the rusty areas.
- Continue to scrub until the rest dissolves.
- If you managed to slice off the surface that contains salt, go ahead and layer more of it with salt and start over.
Citric acid spray
Rust is one of the worst things for your knives. There are some things that can be used to remove rust from knives and citric acid spray is one of them.
This spray is made of citric acid and has long been used as a cleaner. It is a mild cleaner so it is not going to damage the knife blade, but it can help to remove any rust that might be on the knife blade.
This type of cleaner can be used to clean up soap scum, hard water stains, calcium deposits, and more.
- First, make sure the knife is clean.
- Spray the citric acid spray on the knife and on the rust spots.
- Allow the citric acid to sit for a few minutes to help loosen the rust.
- Wipe with a soft cloth, the rust should just wipe away.
- Wash the knife and make sure it is very dry and put it away.
Phosphoric acid is an acid that is made from phosphoric acid and is often used as a mild cleaner. This is something that is going to need to be diluted before you can use it on your knives to get rid of rust.
If you just put your knife in straight phosphoric acid, you are going to be dealing with damage.
- First, wipe the knife clean.
- Dilute your acid to a 25% concentration, this means 4 parts water to 1 part acid.
- Soak your knife in the acid for a few minutes and allow the acid to break down the rust.
- Allow the acid to sit on the knife for a time as it is going to help make a coating on the knife that prevents the rust from coming back.
- Using gloves, remove the knife and then wash the knife and dry it completely before storing.
A whetstone is going to be a manual remover for rust spots. Whetstone is made of a combination of abrasive substances that have been bonded together into a stone shape.
They are often made of things like aluminum oxide, diamond coating, ceramic and more and they are easy to use.
They are a physical remove, this means that you are going to have to use some elbow grease to remove the rust with a whetstone.
- You first need to soak your whetstone in water to allow it time to become wet enough that it is not going to damage the knife. You then need to make sure you choose the right grain on your stone for what you are doing. If you are filing off a ton of rust, you want to use the coarse grain of the whetstone to do so.
- You then need to rub the knife against the whetstone, not the other way around, and work slowly and deliberately to remove the rust from the knife. You can then switch to the fine grain and work to make sure that the surface is smooth and that there is no damage that might be present.
- You need to be careful with a whetstone as it can remove a large amount of the knife and it can damage the blade to the point that it cannot be repaired.
Turpentine can also be used to remove rust from the blade. Turpentine is a type of oil that comes from gum turpentine, or pine, and is often used with paint as a solvent. It is often used to help clean up paint and remove it from brushes.
- Make sure the knife is clean and free of any food or other debris that might be present on the blade.
- Get a cloth and soak it in the turpentine. Use the cloth to wipe at the rust and help to dislodge it.
- You can let it sit on the surface for a few minutes, but you are going to get a better result if you are wiping with a cloth and scrubbing with a rag.
- You can also use a raw potato that has been cut in half and dipped in turpentine as a scrubber.
A cork and makeup remover
You may also be able to use a cork with some makeup remove if you want something that is a bit less toxic or that is made of things that you have hanging around your home.
- Take a cork and cut it open. This is going to expose the raw cork and the more abrasive part of the cork.
- Dip the cork in makeup remover and then rub on the rust spot. This is going to be best for removing very small rust spots.
The last possible thing you can use to remove rust is WD-40. This is a lubricant that is used to help loosen bolts, grease hinges, and more. You can use it to loosen or lubricate the rust so that it can be wiped away.
- Spray the area with the WD-40 and allow it to sit for a few minutes. Around 10 is a good time frame.
- Then, take an abrasive rag or scrubber and scrub the rust to remove it.
There have been many people who swear that this works but it’s still up for debate.
However, the science is still there. Onions contain a chemical called sulfenic acid. Because rust is made from leftover ions produced by the oxidation process, sulfuric acid reacts with the hydrogen ions and dissolves them away.
In order to use an onion to remove rust, follow these steps:
- Slice your onion down to the center.
- Use your onion as a scrubber and make contact between the rusty blade and the sliced area.
- Firmly press down on the onion and scrub in a back-and-forth motion.
- Try to squeeze as much of the onion juice onto the knife as possible.
It may not work as well as any of the previous suggestions stated so far, but it does have rust-removing properties within it.
If you don’t have any other rust-removing tools and wouldn’t mind trying to use onions, then feel free to do so and let us know how it went.
There have always been suggestions that if you don’t have anything else left to clean your knife with, you can go ahead and plunge your knife straight into the ground.
You’re basically going to use the soil and the grit inside of it to clean off the rust from your knife. You’ll want to push it in and out of the soil at least 20 times.
Many people swear upon this method saying that it does work. I suspect that this would only work on lightly rusted knives. However, I believe it’s worth a try if you don’t have any other options.
At the end of your thrusting, make sure you wipe your knife clean and dry. Make sure to store it away in a cool and dry place afterward.
Dawn Powerwash cleaner
This is Dawn’s most powerful cleaning product on the market. But if you’re wondering if it can remove rust, then I’ve got some good news for you. It can!
This detergent is made of blue Dawn dish soap, water, and rubbing alcohol. it’s so powerful, that only after a few minutes of being soaked in the solution, most rust on knives will easily rub off.
- Grab a container that can hold the blade section of the knife.
- Mix a solution of 3:1 water to Dawn Powerwash and fill the bucket up to the height of the blade with it.
- Submerge just the blade into the mixture and avoid the handle. (Unless the handle is made of metal as well and is rusty).
- Leave it inside for at least 24 hours.
- Take it out and scrub down the rusted areas and you’ll find it rubs right off.
Polish with abrasive materials
Rust can be removed from knives by polishing with a fine-grit abrasive.
- Wet the knife before using cream or powdered abrasives.
- Start with coarse grit and move up to a finer grit until all rust has been removed from the blade.
- Use a fine-grit abrasive, such as jeweler’s rouge or buffing compounds, to polish the rust off knives.
- After removing moisture, remove the knife and make it completely dry before storing.
Best care tips for maintaining your knives
Maintaining your knives is an important part of keeping them in good condition.
Here are a few tips for keeping your knives in optimal working order:
Keep them clean
Wipe down your knife with a damp cloth before and after each use, and wash it by hand when necessary.
Store them safely
Store your knives in a drawer or on a magnetic strip so they don’t come into contact with other metal objects that could damage them.
Sharpen them regularly
If you notice that your knife isn’t as sharp as it once was, sharpen it! There are lots of different ways to sharpen knives, from using a whetstone to purchasing an electric sharpener.
Avoid cleaning your knives in the dishwasher
The high water, harsh chemicals, and heat will damage the handle and blade of your knife.
Keep them dry
Don’t leave your knives wet, as this can lead to rusting. Instead, wipe them down and dry them off after each use.
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