The most common acids used to clean concrete and bricks are hydrochloric acid (muriatic) or phosphoric acid. For many years it has been the standard cleaning method to prepare concrete for coatings installations, to remove stains of any type from concrete and to remove concrete slurry or efflorescence from bricks.
The acid works well on concrete and on many masonry projects because it neutralizes alkalinity. The surface becomes “etched” and clean, which allows for the proper adhesion of a new coating. Despite its effectiveness, muriatic acid should be used on concrete stains only if you've tried gentler alternatives to no avail.
To clean and etch concrete, mix one part muriatic acid to 10 parts water. Brush or spray the acid solution on the concrete, wait eight to 10 minutes, then neutralize the acid by spraying the surface with a mixture of one cup of ammonia in one gallon of water.
Use a solution of one part muriatic acid to ten parts water to clean your driveway. Dilute the muriatic acid and pour it into a plastic watering can. Wet your driveway with water, then start at the highest part of the driveway and sprinkle acid over the full driveway surface.
- Acid etching involves allowing the reaction of a dilute hydrochloric acid solution with the concrete surface, then rinsing off with water. ...
- Remove all dust and dirt by brooming and vacuum. ...
- Add 1 part of 33% hydrochloric acid to 2 parts water to make a 10% solution.
Muriatic acid is a form of hydrochloric acid, as mentioned earlier. But while hydrochloric acid contains only HCI molecules, muriatic acid is made up of HCI molecules as well as impurities such as iron.
Muriatic acid is commonly recommended to clean and remove rust stains from concrete. It is also the primary component in most concrete-staining products. In these products, the muriatic acid is mixed with a stain color. The muriatic acid etches the concrete, allowing the color to seep into the concrete.
Start by mixing up a solution of 1 part muriatic acid to 10 parts water in a bucket or spray bottle and soak the stained area. Wait about 10 minutes and then spray the area with a solution of 1 cup of ammonia to 1 gallon of water to neutralize the acid. Pro tip: You must be extremely cautious with muriatic acid.
Hydrochloric acid can be an ingredient in household cleaners such as toilet bowl cleaners, bathroom tile cleaners and other porcelain cleaners, due to its corrosive properties that help clean tough stains.
Mix 1 part Hydrochloric Acid with up to 10 parts water.
Cleaning concrete with muriatic acid can be a highly effective solution if used correctly, providing ultra-bright white concrete and removal of many types of stains. In one application, you can remove rust stains, oil stains, algae, and paint splatter with a quick chemical application followed by pressure washing.
You Can Buy Hydrochloric Acid (HCl) Products Online Or Locally. You can easily buy hydrochloric acid solutions and products in handy household sizes, safe laboratory containers and bulk quantities.
Concrete is a durable building material that takes special materials to dissolve once it's hardened into place. Phosphoric acid and trisodium phosphate are the main compounds used to dissolve concrete leftover from masonry work.
Mix equal parts water and vinegar and apply it to concrete. If this stain removal technique doesn't work, use 100% vinegar and scrub stains out. This solution can work on many surfaces, including car seats and hardwood floors.
Limestone and dolomite (calcium magnesium carbonate) are common neutralizing agents for large-scale muriatic and other acid spills in natural water courses and coal mine water flows. Both materials react with the acid over a period of about 15 minutes to produce salts in a sludge that can be easily handled and removed.
Eye contact with muriatic acid causes serious eye damage; repeated or prolonged exposure to corrosive materials or fumes may cause conjunctivitis. Skin contact causes severe burns; repeated or prolonged exposure to skin will cause dermatitis.
The harmful effects of muriatic acid highly depend on the concentration of HCl in the solution. Once diluted in water, its acidic properties become less intense. As soon as the muriatic acid comes into contact with concrete, it reacts and produces calcium carbonate, a powder residue.
The only differences between hydrochloric acid and muriatic acid are purity—muriatic acid is diluted to somewhere between 14.5 and 29 percent, and often contains impurities like iron. These impurities are what make muriatic acid more yellow-toned than pure hydrochloric acid.
Generally, both Hydrochloric acid (HCl) and Sulfuric acid (H2SO4) are really strong acids compared to any other acids. However, HCl is stronger than H2SO4. This is mainly due to the difference in the basicity of both acids. Additionally, if we look at the pKa value HCl has a pKa of -6.3 and sulfuric acid has a pKa ~-3.
Phosphoric acid is a good substitute for muriatic acid and in most situations will clean surfaces just as well with less risk. Phosphoric acid is a main ingredient in many commercial grout and concrete cleaners that are readily available to consumers.
Apply vinegar or bleach to the discolored areas. If you use vinegar, do not dilute it. Pour it onto the concrete and scrub it into the surface with a scrub brush. If the discoloration starts to fade, repeat until it disappears completely.
Oxalic acid or hydrogen peroxide can be used to help bleach out some of the pigment from the concrete pours. Solutions of sodium hydroxide, xylene, or methyl ethyl ketone are also helpful in removing graffiti. Effective cleaning can also be accomplished with water blasting and sandblasting.
In a bucket, combine 1/2 cup baking soda, 1 gallon of hot water, and a good squirt of liquid dish soap. Use a push broom or stiff brush to spread this around and scrub dirty spots. Rinse, and let it dry. For lingering stains, rewet the surface and sprinkle it with oxygenated bleach.