When I'm called to clean a rust stain from concrete the product I found to work the best is Singerman Laboratories Concrete Rust Remover.
It comes as a white powder. You mix it with water into a clear gel. Spread the gel onto the rust stain and let it sit for two to fifteen minutes depending on how severe the rust is.
The rust stain will start dissolving without having to scrub it. Rinse the area to remove the residual rust.
If any rust stain remains, apply a second treatment, lightly scrub it in and let it sit a few minutes. Rinse it off and the rust will be gone.
ACE Videos did a really good test to show you how Singerman's rust cleaner removed rust stains from concrete.
Check it out below for real proof.
My business, Day's Concrete Floors, Inc specializes in repairing concrete. Removing rust stains from concrete is something I get called to do a lot of.
I've tried all the natural methods for removing rust stains. Baking soda, lemon juice, vinegar, coke, and laundry detergent.
None of them come close to working as good as Singerman's Rust Remover.
I've wasted a lot of time, blood, sweat, and tears using these other products with only mediocre results.
Before I found Singerman's, I tried using just about every other brand of iron out, rust remover product out there.
Sometimes they worked and sometimes they didn't. It was hit or miss.
Singerman's rust remover has worked about 99% of the time for me. Nobody's product is perfect, but this is as close as it gets. (at least in my experience)
When a customer hires me to remove a rust stain from their concrete, I need to be able to tell them with confidence I can do the job.
Now I can. No more "hoping" this will work. No more showing up with 5 different kinds of rust removers.
No more wasting my time!
I'm sharing this information with you because I want to save you a lot of trial and error. I want to save you a lot of time.
But most importantly, I want you to be able to remove your rust stain from your concrete.
Jeff from Diy Remodeling Tips tests 7 different concrete rust remover products.
He very clearly shows you which one works best on rust stained concrete.
The ones he compares are:
This page, this information, is coming from a real concrete contractor. A PRO who cleans and repairs concrete for a living.
There's a lot of other pages on the internet written about removing rust stains from concrete.
I've seen them, and read them. None of these other "authors" are in the concrete business.
That doesn't mean they don't know how to remove rust stains from concrete.
But if they're not in the business, what really is their motive for telling you or showing you what they think works?
Is it to get you to click on their recommended product and buy it so they can get a commission?
I don't know, maybe..... maybe not.
All I know is I do this a lot. This whole website I own is about sharing my knowledge and information with you to HELP you.
Are some of the products I recommend affiliate products also? Yes... But at least I use them.
And... that's how I keep all of this information free for you.
Below, I'll share with you some of these other methods for removing rust stains from concrete I've used in the past.
Just in case you want to try them.
Natural remedies and other brands I've used.
I don't recommend them any more, but they did work on some rust stains.
Most rust stains come from something metal. The metal could be from a vehicle, patio furniture, or a metal can that gets wet and drips on your concrete.
If lawn fertilizer gets on your concrete, then gets wet, it will leave a rust colored stain.
Sometimes the rust stain comes from within the concrete. If the wire mesh or rebar in the concrete is close to the surface and starts to oxidize, this will form rust inside the concrete and a stain will eventually develop.
If you don't like harsh chemicals, another way to remove rust from concrete is with lemon juice or vinegar.
NOTE: Singerman's rust remover is non-hazardous, non-flammable, won't harm your grass, and has no phosphates.
Both of these are quite acidic and make excellent cleaners when diluted with some water.
If you have a heavy rust stain on your concrete, you can try using the lemon juice or vinegar without diluting it first. If it's just a light stain then cut either one 1:1 with water.
Method to clean the rust stain:
If you can still see some rust on the concrete, then repeat the steps above. It may take a few attempts to get the area clean.
If the rust stain is in a difficult area to reach then put it in a spray bottle and spray it on.
The good thing about using lemon juice or vinegar to clean the concrete is if you get some on you it won't hurt your skin.
Note: If you're trying to remove a rust stain on painted concrete, make sure you dilute the lemon juice or vinegar and water solution by using 5 parts water to 1 part vinegar/lemon juice.
The citric acid in lemon juice or the acetic acid in vinegar could damage the paint if the solution is too strong.
Baking soda and vinegar:
You can also try mixing some baking soda with vinegar. This mixture will give you a light abrasive (baking soda), that's good for scrubbing and and acid (vinegar) that helps with cleaning.
Use the same cleaning method as above!
CLR also know as Calcium, Lime, & Rust Remover claims it will quickly and easily dissolve and remove calcium and lime deposits as well as surface rust.
The ingredients of CLR area:
If you watched the video above you saw how this cleaner was not very effective at removing rust from concrete.
At least not on the concrete in the video.
The ingredients used in this to remove the rust are pretty mild.
I have used it before with less than satisfactory results.
I don't recommend this for removing rust stains from concrete.
This is straight from Clorox's website. Dr. Laundry recommends never using bleach to remove rust stains from concrete.
WD 40 is a penetrant that will help loosen the bond between rust and concrete.
This information is from their safety data sheet:
Product Use: Lubricant, Penetrant, Drives Out Moisture, Removes and Protects Surfaces From Corrosion
Contains: Naptha (Petroleum), hydrotreated heavy
H222 Extremely flammable aerosol. H280 Contains gas under pressure: may explode if heated. H304 May be fatal if swallowed and enters airways. H412 Harmful to aquatic life with long lasting effects. AUH066 Repeated exposure may cause skin dryness or cracking.
Although it "may" loosen up some rust and loosen it from the surface, my experience using it as a rust "stain" remover is very good.
It mostly spreads the stain if anything and it's really not very healthy to use.
This is better used for lubricating and protecting metal surfaces in my opinion.
Muriatic acid will remove rust stains from concrete but it will also remove some of the concrete paste as well.
This acid is very caustic and will burn your skin, eyes, and lungs if you touch it or breath it.
If you do decide to use it be very careful and follow the instructions on the label for safety purposes.
I've always cut it 9:1 with water. This dilutes it quite a bit but it's still pretty strong.
The acid will etch the concrete and could leave you with a different texture in that area.
You also have to neutralize the area after using it. A mixture of baking soda and water, 1 gallon of water to 1 cup baking soda, will neutralize the acid and you can rinse it away.
I really don't recommend using this to remove rust stains. it's just too caustic and non-user friendly.
When concrete is placed there's usually some type of reinforcement like wire mesh or rebar used to help minimize cracks.
Sometimes the wire or rebar gets too close to the surface or edge of the concrete during the pour.
After the concrete hardens, you can't see the wire or rebar, but it's there just under the surface. It might be as close as 1 inch under the surface.
Over time moisture gets repeatedly absorbed into the concrete which causes the metal to oxidize (rusts).
Especially if your concrete wasn't sealed properly.
When metal rusts, it expands. The rusting metal (wire/rebar) just under the surface of your concrete begins to bleed through to the surface of the concrete.
Eventually it will expand so much it will pop off a piece of concrete exposing the metal.
The only way to fix this area of rusty looking concrete is to cut out the affected area and patch it back in with a concrete patching material.
You will not be able to just clean the surface with any of the cleaners above because the wire or rebar in the concrete will continue to rust.
You'll have to get the area fixed to resolve this problem.
The only way to make it easier to remove rust stains from concrete is to seal the concrete.
If the rust stains are coming from a vehicle or some type of metal furniture, the stains are still going to get onto the concrete.
But by sealing the concrete, the stains won't soak into the pores of the concrete, they will remain on the surface. This will make them easier to remove.
For exterior concrete I like to use RadonSeal's Dryway concrete sealer.
This sealer will seal your concrete and keep water from penetrating into it. If the rust can't soak into the concrete, you'll be able to remove it much easier.
Get it on Amazon:
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How to clean and remove cat/dog urine from concrete.
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