How to Remove Rust and Corrosion

Co-authored by Mark Spelman

Rust is the result of the oxidation of iron. The most common cause is prolonged exposure to water. Any metal that contains iron, including steel, will bond with the oxygen atoms found in water to form a layer of iron oxide, or rust. Rust will increase and speed up the corrosion process, so upkeep is important. Removing rust is not too difficult. This article will show you how.

Method 1

Method 1 of 5:

Using Acidic Solutions

1
Soak in vinegar. This non-toxic household acid works wonders for rust, among a host of other household applications. Simply submerge the rusted item in vinegar overnight and then scrape the rust away in the morning.
- It's best to use apple cider vinegar instead of white vinegar. While white vinegar may work, it's not as effective as apple cider vinegar.
- Although vinegar is effective, it is also relatively mild. You may need to soak the item for longer than overnight; a day might be best. After removing the rusted item from the vinegar, dip a crumpled-up ball of aluminum foil into more vinegar and scrape away at the rust.
2
Use lemon or lime juice. Lemon or lime juice works particularly well for rust stains on clothing, but it can also be effective on metal if left to work for long enough time. Sprinkle salt over the rusted area, let soak with lemon or lime juice, and then scrape away with a crumpled-up aluminum ball.

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3
Get scientific with phosphoric or hydrochloric acid. Phosphoric and hydrochloric acids are common household items that are inexpensive and work well on rust. Here's what you can find them in, and how to use them:
- Phosphoric acid is actually a rust "converter" in that it turns iron oxide (or rust) into ferric phosphate, a black coating. Soak the rusted material in phosphoric acid and leave overnight. Then let dry. Scrape off the ferric phosphate after the surface has dried. Phosphoric acid can be found in cola drinks, naval jelly, and molasses.
- Hydrochloric acid is often used in the steel industry to "pickle" steel by removing rust or scale. Hydrochloric acid can be found in several home cleaning agents, most numerously in toilet bowl cleaners.^{[1]
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- Hydrochloric acid keeps on working even after rinsing and drying. Vapours can affect other, polished, and metal objects in the same room and discolour them. One way to prevent this is to heat the treated object in an oven or fire. Another is using a neutralizing paste of chalk or lime.
4
Use a potato. The oxalic acid in potatoes helps remove the buildup of rust. This method is especially useful for smaller rusted items, such as knives. There are two ways you can use a potato to remove rust:
- Simply stab the knife into potato and wait a day or overnight. (Be careful when stabbing the potato.) Remove the knife from the potato and scrub away the rust.
- Slice a potato in half, coat the inside with a generous portion of baking soda, and go to town on the rusted surface with the baking soda-coated potato. Wipe afterwards with an abrasive material, such as steel wool.
5
Check to see what other acids you have available in your home. Often times, you can create your very own rust removal solution without even leaving the kitchen. Pretty much anything acidic will start to loosen and eventually remove the iron oxide. Homemade solutions work particularly well with smaller rusted objects.^{[2]
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- The active ingredient in most store-bought chemical solutions is some form of acid, usually phosphoric or hydrochloric, and most acidic substances found in your home can perform the same trick.
- If you have any questions about interactions of acids or chemicals, do some quick research before using them. Although most household items are perfectly acceptable to use in combination, some interactions are best avoided.
6
Remove rust with fizzy cola drink. Place the rusty item inside of a glass or larger vessel filled with cola drink. Simply let it sit or just dip it. After each half hour, check for progress. The cola should do the job.

Method 2

Method 2 of 5:

Using Pastes

1
Make a baking soda paste. Mix enough baking soda and water together to form a paste a little bit thicker than toothpaste.^{[3]
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Research source} This will require slightly more baking soda than water. Once the paste is mixed, apply to rusted material and begin working in with an abrasive, such as steel wool or a toothbrush. Wipe off and inspect the site.
- You may need to use several applications of your baking soda paste in order to see results, but the process definitely works.
2
Make a paste of hydrogen peroxide with cream of tartar. Achieve the same consistency as the baking soda paste by using slightly more cream of tartar than hydrogen peroxide. Apply to rusted material, work in with an abrasive, and then wipe off.
- If you do not have hydrogen peroxide, you can also use water to similar effect. The active rust-busting ingredient here is cream of tartar.

Method 3

Method 3 of 5:

Using Mechanical Abrasion

1
Obtain a power grinder or sander if you don’t own one already. They are readily available at any hardware store, although since they are power tools, they are likely to have hefty price tags. Many hardware supply stores such as Ace Hardware and the Home Depot rent out such tools for a significantly smaller fee. Power grinders are particularly useful for larger rust-covered surface areas such as on old cars.^{[4]
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2
Fit the grinder with the coarsest disc available. Grinders are equipped with removable discs which are interchangeable and replaceable once they’ve been worn down to uselessness. Stripping, fiber, and flap discs work well.^{[5]
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- It is best to start grinding away the rust using the largest, toughest of these to quickly do away with the worst of the rust and avoid needlessly wearing down the smaller, more sensitive ones.
3
Secure the rusted material so that it will not move when you grind away the rust. Clamp it down with a vise, if possible, or make sure that it's heavy enough to stand still while you sand away.
4
Turn on the power grinder. Switch on the power grinder and brush the rotating disc against the rust gently but firmly. Be sure to keep it in constant motion to avoid accidentally gouging the metal.
5
Use a power sander to finish the rust off. If any minor rust remains, sanding should get rid of it. Power sanders work just like power grinders, except that they vibrate a sanding pad rather than rotate a disc.
- Detail sanders are specifically designed for hard to reach places, and should be used for rust on corners and uneven surfaces.

Method 4

Method 4 of 5:

Using Electrolysis

1
Set up an electrolyte solution. First of all, this method is much easier than it sounds. Fill a plastic bucket with enough water to submerge your rusted object and mix one tablespoon of baking soda or washing soda per gallon of water. Use hot water, the warmer the water, the better. Mix well until it dissolves.^{[6]
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2
Use a different, sacrificial piece of steel as an anode. The electrolysis process will take the rust from the object you want to clean and eventually attach itself to this metal. You want the sacrificial anode to be big enough so that half of it is submerged and the other half — the half onto which you attach your positive terminal — is above water. This is very important.
- A steel can works fine as your sacrificial anode, provided it is big enough to be partly sticking out of the water. Rebar is good too.
- Make sure the can anode is magnetic to avoid confusing it with aluminum. You do not want to use aluminum or stainless steel as your sacrificial anodes for electrolysis.
3
Connect a negative terminal. Connect a negative terminal (black in color) from a battery charger to a rust-free section of your rust-covered object for a good connection. You may have to manually scrape away some rust to achieve this. Fully submerge the rusty object, taking care to keep as much as possible of the wire out of the water.^{[7]
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- Caution: Make sure this rusted object does not touch the anode to prevent an electrical short-circuit (a short).
4
Connect a positive terminal. Next, you will need to connect a positive terminal (red in color) from the battery charger to the sacrificial metal. Remember not to submerge the sacrificial metal completely, or you'll risk eating away at the positive terminal, which you don't want to be eaten away.
- If the sacrificial metal is completely submerged, consider using another wire as a mediator/connection between it and the car battery charger lead to keep the charger terminal and connection dry.
5
Plug in the car battery charger and turn it on. The electrolysis process will gradually start working away at the rust. Let it sit for 12-20 hours.
- Caution: If you ever want to check the status of your rusted object, be sure to turn off and unplug the battery charger first. You will see bubbles rise to the surface and muck gather at the surface. Both of these things are normal.
6
Unplug the car battery and remove the leads from your objects. When taken out, your rusted object should be rust-free, but still in need of some cleaning. Use a Scotch Brite pad to remove any sludge on the object and a bristle brush to clean those harder to reach spots.

Method 5

Method 5 of 5:

Using Commercial Chemicals

1
Purchase a chemical rust remover. Yes, they exist, but often the main component is some form of acid which can cause the fumes to be toxic or semi-toxic. The rust removers can be purchased at any hardware supply store and some auto body shops.^{[8]
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- Some optional brands include Evapo-rust, Metal Rescue Rust Remover Bath (safe on paint, plastics, and skin), Acid Magic, The Works (20% HCL, hydrochloric acid), The Works Basic (9.5% HCL, hydrochloric acid) and WD-40 (light weight oil).
- Use protective wear when handling commercial rust removers. Protective wear includes goggles, gloves, and a face mask or respirator.
2
Apply the solution. This is where the rubber really hits the road. You want to give the cleaners time and elbow grease to work their magic. You can do this in several different ways:
- Some chemical solutions come already in a spray containers. Spray lightly and accurately onto rust and let sit overnight for heavy rust.
- Other solutions need to be applied by using a brush. Scrape off any rust that can be easily removed and evenly apply the solution. Let sit overnight.
- Another method is total submersion. If an item is small enough, find a plastic paint bucket or other container and place the rusted item in it. Pour enough rust remover solution to completely submerge it and let it sit overnight.
3
Rinse with water and dry. Try to get as much of the commercial rust remover off your item as possible. Hit the item with a blowdryer, if possible, so that the item is completely dry and rust is discouraged from returning.
4
Scrape off any remaining rust. Most of the rust should have been loosened overnight and the remainder should come off easily.
5
Repeat the process if necessary. The amount of wait time necessary to remove the rust depends on the item in question, how badly it is rusted, and how well the store bought product works. Sometimes the metal needs to be treated with the solution more than once, particularly if the rust is on a vertically standing object.

Expert Q&A
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Question

Is it better to use phosphoric acid for rust removal?

Mark Spelman
Construction Professional
Mark Spelman is a General Contractor based in Austin, Texas. With over 30 years of construction experience, Mark specializes in constructing interiors, project management, and project estimation. He has been a construction professional since 1987.

Mark Spelman

Construction Professional

Expert Answer

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Yes, this chemical works well. Make sure that you wear gloves and protect your eyes and skin.

Warnings

Determine the precise metal of your object. Rust is another word for iron oxide, which only forms on iron or metals that contain iron, such as steel. All metals corrode, albeit in different ways, and other metals have their own ‘version’ of rust. Some of the methods described above, such as electrolysis, are designed specifically for rust and should not be attempted to clean other metals.

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Take special care when using electrolysis to clean rust. You are using live electrical currents. Make sure your container is non-conducive (plastic works best), use rubber gloves, glasses, and a mask, and do not allow the negative and positive wires to come into contact.

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Grinding and sanding unevenly can grind away at the metal itself. If a particular object is valuable, consider using a chemical solution or electrolysis.

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Avoid breathing any strong acid fumes; always provide adequate ventilation when working with an acid. It can irritate the throat and lungs, especially in those people with asthmatic or lung conditions. Consider using eye and mouth protective wear such as goggles and a face mask. When working with store bought acidic products, always use protective gloves, a mask, and protective glasses.

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