Removing Rust Stains from Concrete
Rust stains randomly dotted across driveways, patios, porches, and other concrete surfaces look unsightly, and such blemishes are a particular burden to anyone who takes pride in the appearance of their home and its surrounding landscape. Fortunately, removing rust stains from concrete is a relatively simple task. As with most stains, the sooner the source of the stain is removed, in this case the rust, the easier getting the stain out will be.
Preparation
Rust stains are different from rust, so don’t attempt to tackle solid, caked-on rust with any of these stain removing options and expect success.You must first remove the rust , and if a stain remains, clean the area where the stains are located.
Preparation for cleaning solutions includes sweeping away leaves and debris on the concrete as well as anything else that can get in your way or prevent you from getting at the entire stained surface.
Natural Solutions
Using natural products is one of the most effective and inexpensive routes for removing rust stains from concrete. Many of these solutions are common household items with the high acidity needed for removing stubborn rust stains. Acid reacts with the rust and causes it to dissolve.
Lemon juice or vinegar is a good solution to remove rust stains. Always use undiluted liquid, as it will be more acidic than a diluted alternative.
Pour the lemon juice or vinegar straight onto the stain and leave it to penetrate into the rust for approximately 10 minutes. Then, take a hard-bristled brush and scrub at the rust stain applying a considerable amount of pressure. Rinse off the area with some cold water.
If you have any rust stains in hard to reach areas or on walls, patio furniture, or plant pots, using a spray bottle to apply either lemon or vinegar will work much easier than trying to pour it on the stain at difficult angles.
When cleaning rust stains in close proximity to plants or foliage, be careful with your spraying. The high acidity in both cleaners is great against rust, but will damage plants. This may be one situation where you’ll want to dilute the solution of your choice with water. This will spare your plants and will still work on rust stains, the only catch being that you might have to use a little more elbow grease to make up for the lack of acid.
Carbonated Drinks
Carbonated drinks like Coca-Cola are very good at removing rust stains. All you need to do is pour some of the liquid over the rust stain and leave for about ten minutes. Use a brush to scrub away the stain and rinse thoroughly with water.
Hydrochloric Acid
If you have stubborn rust stains on your concrete you can try using Hydrochloric acid. Hydrochloric acid is also known as muriatic acid. When handling hydrochloric acid always make sure that you have protective gear like gloves and a respiratory mask. Make a mixture by mixing the acid and water in the ratio of one part acid to two parts water. You must pour the acid into the water and not the water into the acid. This is so that you avoid any adverse exothermic reactions.
Pour this mixture onto the stain and leave for ten minutes and not longer as it can cause discoloration to your cement. Scrub the cement vigorously with a brush then rinse thoroughly with plenty of water.
Laundry Detergent
Depending on the stain, laundry detergent on its own can remove rust stains. However it is recommended that you mix the laundry detergent with baking soda for a more potent mix. Exact measurements do not matter but two parts detergent to one part baking soda is a good mixture. Do not make too much of the mixture as you will have trouble rinsing the soapy suds.
Rub the mixture into the stain and leave for about 10 minutes. Scrub vigorously with a brush and rinse thoroughly with water.
Commercial Cleaners
If the solutions given above fail to remove the rust stain, you will need to buy a commercial rust remover that contains oxalic acid. This type of acid is harsher than lemon juice or vinegar, and it is also toxic. Therefore, be sure to apply the oxalic acid solution when no pets or young children will be present.
Even though many concrete stains occur outdoors, if you are working with oxalic acid in an enclosed area such as a garage or basement, protect yourself from fumes by opening up the space or using a ventilator.
DISCLAIMER: Follow any manufacturer instructions provided with your product of choice and wear safety gear such as rubber gloves, protective goggles, and long garment to cover your skin from exposure.
Prevention
Metal garden furniture are the objects most commonly prone to rust stains. The chance of outside furniture being covered in such marks can be dramatically reduced by applying a coat of paint to metal furniture at least once a year.
Similarly, if future rust stains are a big concern for you, your larger priority should be preventing rust. No rust, no rust stains.