DIY projects are not always done using new materials. If you have a project that requires the use of second-hand metal, it’s not uncommon you’ll have to deal with rust. To create quality products with this metal, you want to remove this rust.
What is the best DIY way to remove rust from metal? Removing rust can be done effectively at home through abrasion, dissolving it in acid, use pastes, or electrolysis. After you remove rust, what remains should be metal that is as good as new—and ready to use for your DIY projects.
We’ll take a look at how we can apply these strategies in practice and why they are useful to remove rust. All the methods can be done quickly from your own home. We’ll only use products that are very common in most households, so with a bit of luck, you’ll be able to start right away.
Why does metal rust in the first place?
Metal rusts when the iron it contains starts to oxidate. The most common reason this happens is prolonged exposure to water. What happens is that the iron in metal starts to bond to the oxygen-atoms the water contains. This process turns the iron into iron oxide (rust).
Iron oxide is very weak, so it’s essential to keep metal rust-free. Once rust sets in, it will significantly speed up the corrosion of metal. Luckily it’s not very hard to remove rust. You’ll just need to treat the rusted object with a substance that is capable of dissolving the oxidized material.
Let’s take a look at the most effective ways to do this from home.
1. Use acid to remove rust
One of the most used methods to remove rust from metal is acid. There are several acids you probably have around the house that can be effective for this purpose.
So which types of acids are best to remove rust?
With this method, we mean the old submerge-it-into-cola solution. Albeit it might seem a bit strange, it actually does an excellent job to remove rust from metal objects.
- Cola type soft drink
- Glass or Ziploc bag
The easiest way to use phosphoric acid to remove rust is by placing a rusted item into a type of cola drink. Just leave the rusted object in there and check every forty-five minutes to an hour how the process progresses. You don’t have to do anything else, just let the cola do its magic.
Because phosphoric acid is non-toxic and only mildly acidic, it can be found in numerous products that we use daily. Among other things, it’s used for food flavoring, cosmetics, beverages, and dental products.
Phosphoric acid doesn’t dissolve the rust as most other acids do, but instead, it converts iron oxide into ferric phosphate. Instead of the rust, the only thing that should remain – after this process – is a blackish coating that should be easy to remove.
You can find this effective rust remover in just about every supermarket or drug store. It’s relatively safe to use and will get the job done.
- Citric acid powder (supermarkets sell this as a baking product)
- Warm water
- Rubber gloves
- Steel wool or a steel brush
- Glass or Ziploc bag
The big advantage citric acid has over other options is that is doesn’t damage the steel finishing. If you are using delicate products, then citric acid might be your best bet.
The way it works is very straightforward. Make sure you clean the rusted item before covering it in warm water. Then just pour in the citric acid powder in, at a 20:1 water to powder ratio. Gently stir the water and the acid powder. You should see light bubbles appearing after several minutes. If the bubbles don’t appear, simply use more citric acid powder.
Let the rusted item sit in the citric acid solution for somewhere between two to four hours. If the item is rusted heavily, then just leave it in the mixture overnight. That should do the job, even when the rust is severe.
After you take the rusted item out of the citric acid, just clean and remove the rust with some steel wool or a steel brush. Rinse the item afterward for a clean finish. After you’re done removing the rust from your object, pour the remaining mixture down the sink. It’s harmless for the environment.
If you’re looking for a mild way to remove rust, then vinegar might be a good option. It’s pretty effective, but it will take a bit more time than most other acids.
- Apple cider vinegar (or white vinegar)
- Glass or Ziploc bag
Soak the item you need to remove rust from in vinegar and let it sit overnight. Because of its mild nature, you want to soak the item longer into vinegar than you would do with most other acids. It might well be you have to wait a whole day before you get the result you were looking for.
Apple cider vinegar works better than regular white vinegar, but if you don’t have any around, then white vinegar will also get the job done. It might just take a bit longer.
The best way to remove the last residue of rust is to soak a crumpled ball of aluminum foil into the same vinegar and use it to scrape away the last remaining rust on the item that has been treated.
In terms of safety, hydrochloric acid might be the substance to treat with the most caution. It’s very aggressive but also very effective in removing rust. You can find it in a lot of home cleaning agents like toilet bowl cleaner.
- Hydrochloric acid
- Wire brush
- Rubber gloves
- Plastic or rubber surface
Let’s start with safety. Always wear gloves when working with hydrochloric acid. When it comes in direct contact with skin, it will immediately begin burning. Secondly, do not pour the acid into metal containers. There’s a good chance it will eat through the metal.
Now for the rust removal properties of hydrochloric acid: it’s excellent for removing rust when the object is severely oxidated. Just wipe on the acid on the rusted object with a wire brush, and check how it progresses.
Be aware though that the acid will continue to work, even after rinsing it off. It’s better to do this before the process seems to be finished. The fumes could have a coloring effect on other metal objects in the vicinity. A way to prevent this is to neutralize the acid by heating it with fire or an oven, or treating it with lime or chalk.
For future preservation of the treated item, a finish with phosphoric acid treatment can be beneficial. This will give the metal a protective coating.
Lime or lemon and salt
Another natural way to remove rust from metal objects is treating it with lime and salt. Very safe, yet it still does a good job.
- Lime or lemon
This method is very safe and easy to do. All you need to do is coat the rusted area of the object in salt. Plain kitchen-salt will do just fine. After that squeeze the juice of a lime or lemon on top of the salt.
Let it rest for a few hours and scrape off the lime and salt with the rind of the citrus fruit. This way the rust will come off just fine, without causing any further damage to the metal.
Use a potato to remove rust
Yes, you’ve read that correctly. You can use a potato to remove rust from metal objects. However, this method only suits smaller objects like knives or metal rulers.
- Dish soap or baking soda
The main idea is that the oxalic acid in the potato reacts with the rust. There are three ways to get rid of rust with a potato:
- Stab the rusted object into a potato – After that just let it sit there overnight. After removing the object from the potato, remove the rust with steel wool. If the rust was not too severe, this should be enough to get rid of it.
- Potato + dish soap – Slice a potato in half and put it on the rusted surface. Before doing so, rub dish soap on the sliced area and put that directly on the object and leave it there for a few hours. The addition of the dish soap will make sure the rust comes off easier.
- Potato + baking soda – Slice the potato in half and rub baking soda on the sliced surface. To get rid of the rust, use this area to scrape off the rust by rubbing it with significant force against the rusted area until the rust comes off.
2. Use abrasive tools to remove rust
A simple way to remove rust is to just scrape it off with an abrasive tool. We’ll take a look at the most accessible options, as well as some ways to make this process more effective.
If your item is not too severely rusted, using sandpaper can be enough to remove rust from metal objects. Most people have it around the house so you should be able to start right away.
If there is a lot of rust to remove, start with a low grit size to speed up the process and move to a higher grit size once you only have to remove the last bits of rust or to polish up the metal for a beautiful finish.
Just about everyone has steel wool around the house. The big advantage it has to remove rust is the durability of steel wool and the small amount of potential damage it will inflict on the metal.
Just go to town with your steel wool on the rusted area. To get a good feel for the progress you’ve made, it’s a good idea to rinse the metal every few minutes. Good results can take a while longer with steel wool, but a polished and undamaged finish is almost guaranteed.
A power grinder can be an excellent tool to get rid of rust. You can take on even the most severely rusted items and still get good results in a matter of minutes. It’s a good idea to use more coarse discs. This will speed up the process and will result in less wear on your discs.
Always make sure to secure the item you want to grind down, so it will stay firmly in one place. Also, don’t keep the power grinder too long in one place. You want to gradually grind off the rust and be aware of how much rust is still left. When it’s not done like that you risk damaging the metal.
A power grinder works best on flat surfaces. If you’re trying to remove rust from complex shapes, you’ll have a hard time getting decent results because of the flat shape of the plates you’re using to grind.
After you got rid of most of the rust with a power grinder, a sander can be an excellent tool to finish up the job for a nice and clean finish. If you own a power grinder, chances are you’ll own a sander as well, so why not go all the way.
Add a cream of tartar paste
If you’re looking to save time and effort when using abrasive tools to remove rust from metal, cream of tartar can do just that. Simply apply it to the rust and get at it.
- Cream of tartar
- Wire brush, steel wool or toothbrush
Cream of tartar is the potassium acid salt of tartaric acid. When applied to rust, it will react with the oxidized material—as a result, the rust will come off a lot easier.
Mix some water and cream of tartar in a 2:3 ratio. This should result in a paste a little thicker than toothpaste. If it’s too thin, add some more cream of tartar until you get the right consistency.
When you’re done mixing the paste, cover the rusted surface with it and start using abrasive tools like you usually would. It’s not a big deal if you need to repeat the process a few times. It’s not the fastest method, but it works pretty well for such a non-aggressive substance.
Add a baking soda paste
A paste that consists of baking soda and water can be a practical way to get a better result while you’re using abrasive tools to remove rust. It works very similar to the cream of tartar paste.
- Baking soda
- Wire brush, steel wool or toothbrush
Just start with making a paste that is a little bit firmer than sun lotion. An excellent way to achieve this is to mix the water and the baking soda in a 2:3 ratio. Always check to make sure it has a good texture.
After that pour the paste on the rusted area’s and start using an abrasive tool like a wire brush or steel wool to get rid of the rust. You might have to re-apply the paste a few times, but it will save you a lot of time and energy, compared to not using the paste.
3. Use electrolysis to remove rust
This method might seem a bit sciency at first glance but bear with me a bit. Once you try this, you’ll understand how easy and effective it actually is. Don’t be fooled by the idea that it looks like a high school chemistry experiment. It does, but it also works really, really well.
- Baking soda
- Hot water
- Car battery charger
- Plastic bucket
- A disposable piece of magnetic metal
Start by filling the plastic bucket with hot water, until you can submerge the item you want to free from rust entirely. Now add the baking soda. A tablespoon per gallon should be about right. Stir the water until the baking soda dissolved completely.
Now put in the item that needs rust-removal, as well as the piece of magnetic metal you’re going to use. Make sure that about half of that piece of metal remains above the water. This part is pretty vital.
Take your car battery charger (not plugged in yet) and connect the negative terminal (the black one) to the object from which you want to remove the rust. But make sure you connect it to a part of the object that has no rust—the terminal has to be in contact with unrusted metal.
After that connect the positive terminal (the red one) to the unsubmerged part of the second piece of metal. Again, be sure this part isn’t wet or submerged, or it will fail.
When everything is set up, plug in the car battery charger and wait somewhere between 12 and 24 hours. The rust now should be transferred from the rusted item to the second piece of metal.
If you want to stop the process, always make sure to unplug the car battery charger before you take out the metal objects. After that, clean your now rust-free item, and you should be good to go.
We’ve looked at several easy DIY strategies to remove rust from metal objects. They differ in effectivity and efficiency. Before you start to remove rust, ask yourself some of these questions:
- Do you have the products at your house needed for specific strategies?
- How severe is the rust on the object you want to clean?
- How much time do you have to remove the rust?
- Are you aware of the risks involved with some of the more aggressive methods?
- Is it important to keep the item completely free from damage?
After you’ve answered these simple questions, look at your options and decide how to proceed. Not all rust needs an aggressive approach. The only thing you want to achieve is removing rust from metal. If you can do that with an easy and safe method, always choose that one instead of the riskier alternatives.