How To Remove Rust Stains From Concrete
Rust stains on concrete are actually quite a common and ugly problem. They can be caused by fertilizers, soft rock like limestone, or just imperfections in the concrete mix. Getting rid of them may not be as difficult as you may think.
Mix 1 cup of lemon juice with 1 cup of vinegar, let it sit for 15 minutes, brush the stain, and wash it with warm water. You can also mix CLR with water in a pump sprayer, then spray and scrub the stain. Wash the CLR away after no more than 2 minutes to remove the stain.
While some of these cleaners are natural, they can all be skin and eye irritants and most of them are not good to breathe. Therefore, it is best to wear a mask, goggles, and gloves while working with any of these concoctions.
Do You Need a Maid Service?
Get free, zero-commitment quotes from pro contractors near you.
Muriatic Acid
Also known as hydrochloric acid, this is the most effective way to remove rust stains. But you have to be careful not to leave it on too long or it will turn your concrete blue. And while blue is nicer looking than rust, it is still probably not what you want in your concrete. Follow these steps carefully.
- Step One: Put on your mask, goggles, and gloves.
- Step Two: If working indoors, use a fan to suck the fumes out of the air while you work.
- Step Three: Mix two cups of muriatic acid to one cup of water in a bucket or sprayer.
- Step Four: Apply the acid solution and let it soak for 10 minutes.
- Step Five: Rinse the area with a high-pressure washer or hose with a sprayer.
- Step Six: Repeat as many times as needed.
CLR Calcium, Lime, and Rust Remover
Well, it is right there in the name so it must get rid of rust, right? It does have some harsh chemicals, but it is also approved by the Environmental Protection Agency (EPA) as being a safer choice than traditional methods. Use the following steps.
- Step One: Put your gloves, mask, and goggles on.
- Step Two: Mix equal amounts of water and CLR in a pump sprayer or bucket.
- Step Three: Apply it directly to the stain and scrub it with a brush or push broom.
- Step Four: Rinse the cleaner off right away. Do not leave CLR on for longer than two minutes.
- Step Five: After the concrete dries, if the stain is still there, you can repeat the process.
Important Note: Never mix CLR with bleach or other cleaners.
Acid Magic
This is a product with some muriatic acid in it, but it also includes other unknown cleaners that seem to help. It is buffered to make it less toxic than straight acid though. Follow these steps to get rid of the rust stain on your concrete.
- Step One: Get your gloves, eye protection, and mask on first.
- Step Two: Mix the Acid Magic with water in a pump sprayer or bucket as suggested on the label.
- Step Three: Spray or pour the cleaner onto the rusted area.
- Step Four: Wait for 30 to 45 minutes.
- Step Five: Scrub the concrete with a push broom or stiff brush.
- Step Six: Rinse it away with water and reapply if there are any rust spots remaining.
- Step Seven: Repeat as many times as needed.
Important Tip: Try not to get any acid on the grass nearby or make sure you wash it away with a soaking hose for about an hour.
Simple Green Oxy Solve Concrete and Driveway Cleaner
Made for concrete and driveways, this product is great for removing all kinds of stains including rust, grease, oil, and exhaust buildup. You can either use it in a pressure washer or with a spray bottle and brush.
- Step One: Be sure to put on your gloves, mask, and gloves before using.
- Step Two: Add one cup of Oxy Solve to one gallon of water.
- Step Three: Spray the area and let it sit for five minutes.
- Step Four: Use a stiff bristle brush or push broom to work the mixture in.
- Step Five: Rinse the cleaner away with a hose or sprayer.
Pine-Sol
This common household cleaner actually removes the stain if you scrub it hard enough. Just follow these easy steps.
- Step One: Put on your mask, eye protection, and gloves.
- Step Two: Sweep the concrete to get rid of any dirt or debris.
- Step Three: Mix one gallon of warm water with a quarter-cup of Pine-Sol.
- Step Four: Pour the mixture onto the stain and wait about 30 minutes.
- Step Five: Using a push broom or hard-bristle brush, scrub the stain until it comes off.
- Step Six: Rinse with a pressure washer or hose.
WD-40
WD-40 has a special rust remover soak that comes in a one-gallon jug. It will take rust off tools and other metals and claims to remove rust from concrete as well. Although it says there are no acids or toxic fumes, wear your protective equipment anyway.
- Step One: Pour the rust remover onto the rust stain and leave it to sit for at least three hours.
- Step Two: Re-apply the rust remover every hour to keep it from drying out.
- Step Three: Rinse the concrete thoroughly with a high-pressure sprayer or hose.
- Step Four: For stubborn stains, leave the rust remover on overnight and then clean it away.
Oxalic Acid
There are many cleaners on the market that have oxalic acid in them. Some of the more popular ones include Simple Green, F9 BARC, Singerman’s, Iron Out, and Bar Keeper’s Friend.
- Step One: Get your goggles, gloves, and mask on.
- Step Two: Mix the cleaner as suggested on the label.
- Step Three: Let it sit for 10 minutes.
- Step Four: Wash away the cleaner with a hose that has a sprayer on it or a high-pressure washer.
Trisodium Phosphate
Also known as TSP, this cleaner can be found at hardware and home improvement stores. You have to be careful with it because it is basically just muriatic acid mixed with sodium hydroxide.
- Step One: Wear your gloves, goggles, and mask.
- Step Two: Add one cup of TSP to one gallon of hot water in a bucket.
- Step Three: Pour the solution on the rusted area and let it sit for 20 minutes.
- Step Four: Scrub the concrete with a stiff nylon brush. Do not use a metal brush. Working in circles, scrub until the stain lifts away.
- Step Five: Rinse the TSP solution away with a high-pressure washer or hose with a sprayer.
Lemon Juice and Vinegar
For a more natural cleaner, try lemon juice mixed with white vinegar. However, you should still wear protective equipment to protect your skin, eyes, and lungs.
- Step One: Mix one cup of lemon juice and one cup of vinegar together.
- Step Two: Wait 15 minutes and then scrub with a hard bristle brush.
- Step Three: Rinse the area with water from a bucket, hose, or sprayer.
- Step Four: Repeat as needed.
Laundry Soap and Baking Soda
Similar to lemon juice and vinegar, this cleaner is a less toxic choice than the others. However, the washing powder does typically have some harsh chemicals in it, so you have to wear your protective mask, goggles, and gloves.
- Step One: Mix one tablespoon of soap to one tablespoon of laundry soap in a disposable cup. If you only have powdered laundry soap, you will have to add enough water to make a paste.
- Step Two: Fill a spray bottle with hot water.
- Step Three: Using a paintbrush, apply the paste onto the rusted area.
- Step Four: Leave it on the stain for an hour, keeping it moist by spraying it with the water.
- Step Five: Scrub the stain vigorously with a stiff brush.
- Step Six: Rinse thoroughly with a hose or sprayer.
- Step Seven: Repeat if needed.
Lemonade
This trick does not seem like it would work until you think about the fact that lemonade has acid in it just like lemon juice. Maybe not as strong but that is why you do not mix it with too much water.
- Step One: Mix one packet of unsweetened lemonade with one cup of hot water in a spray bottle or bucket.
- Step Two: Pour the mix onto the stain.
- Step Three: Scrub it with a stiff brush or push broom.
- Step Four: Wash away with a hose or sprayer.
- Step Five: Repeat as necessary.
Coca-Cola
Because Coca-Cola has acid in it, the soft drink works pretty well for cleaning things too. There are many things you can use Coca Cola for besides drinking. Follow these steps for cleaning the rust from concrete.
- Step One: Pour the full-strength Coca-Cola on the rust and let it sit for 15 minutes so the acid penetrates the stain.
- Step Two: Using a push broom or scrubber brush, scrub the stain until it is gone.
- Step Three: Wash the area with a hose or pressure washer.
- Step Four: Pop another Coca-Cola and repeat these steps if the stain remains.
- Step Five: Drink the rest of the Coca-Cola and enjoy your clean concrete.
Do You Need a Maid Service?
Get free, zero-commitment quotes from pro contractors near you.
Related Questions
What Are Some Other Uses for Coca-Cola?
You may be shocked at some of the things you can use a can of Coke for. Whether you use the brand name or generic, it should work either way. Here are some of the uses:
- Removing tar from your car
- Preventing diarrhea
- Cleaning pennies
- Killing snails and slugs
- Use it like hairspray or mousse
- Cleaning your glasses
- Getting rust out of your tub
- Conditioning your hair
- Cleaning hard water stains from a teakettle
- Fertilizing your garden
- Cleaning your toilets
- Making BBQ sauce
There are several good ways to prevent rust on your concrete, so you do not have to do this again. Some of these include:
- Using concrete sealer
- Keeping metal away from your concrete
- Coating your metal outdoor furniture with sealant
- Do not use fertilizer near the concrete or wash it away after use
I am a DIYer who loves writing about anything home-related. When I am not writing, you can find me studying for my PhD in Psychology, photographing nature, and swimming at the lake with my grandkids.
More by Patricia Oelze
