When cleaning with basic pH chemicals such as sodium hypochlorite, you remove dirt, mold, and algae from surfaces easily, but do not get the brightening effects acidic pH chemicals, such as muriatic acid, provide. Muriatic acid can provide that bright white look that new concrete often has.
Over time, it can destroy concrete as the acid weakens its structure. This will cause scaling, pitting, peeling, and cracking. If the acid wash gets into the soil, it will evaporate on the surface but remain beneath the surface (just like it does with concrete).
Muriatic acid can work wonders on filthy concrete. However, it shouldn't be used on penetrating sealers since it can damage these finishes. It might also damage some acrylic sealers, so test a small area if you're not sure.
A solution of 40 parts water to 1 part muriatic acid, a scrub brush and cotton rags will help remove the stain. Keep in mind that acid stains are not soluble in water. This means that water alone will not do much in regard to removing the orange-colored stain.
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.
Any concrete that is not properly neutralized will begin decomposing immediately. It may take time for the damage to reach the surface where you can see it, but it is happening and is usually irrepairable.
Brightens concrete.
When cleaning with basic pH chemicals such as sodium hypochlorite, you remove dirt, mold, and algae from surfaces easily, but do not get the brightening effects acidic pH chemicals, such as muriatic acid, provide. Muriatic acid can provide that bright white look that new concrete often has.
Acid stains are a reactive coloring process that penetrates into the porous concrete surface. This is probably the most permanent of all coloring options but is usually limited to eight colors.
You don't want all your hard work to go to waste by not neutralizing the acid stain properly. Ensuring proper neutralization is crucial for sealer bonding and a durable, aesthetically pleasing finish. Without it, you might end up with a peeling, blotchy surface that just won't do justice to your efforts.
Step 1: If the acid stains are fresh or recent, take a generous amount of baking soda to sprinkle over the stain. Whereas if the acid stain is old, you can make a thick consistency paste of baking soda with water and apply it on the stain to cover the whole area. Step 2: Wipe it off after a few minutes with a cloth.
Our top pick for an alkaline concrete cleaner, Sunnyside 64216 TSP All Purpose Cleaner, is recommended for indoor surfaces and works quickly to remove tough stains. Acid concrete cleaners are made with phosphoric acid or hydrochloric acid, which cause a chemical reaction that lifts stains.
Mix one cup of TSP (trisodium phosphate) in a gallon of hot water, then pour the solution over the blemish. Let it soak in for at least 30 minutes, and then scrub with a stiff nylon brush. Finally, blast the spot with your hose set to the highest pressure.
A white haze, white streaks or white, powdery dust on the surface after drying is caused by waiting too long before rinsing or by inadequate rinsing. The white powder is a combination of cement particles released from the surface and a precipitate byproduct of the etching reaction, insoluble calcium phosphate.
A ½ teaspoon of baking soda will neutralize 1 cup of an acidic ingredient. Just a little baking math – Recipes often employ a combination of baking powder and baking soda, using just enough baking soda to neutralize the acid in the recipe, but also enough total leavener to lift the flour in the recipe.
So while you don't have to seal concrete, if you do, you will be enhancing and protecting the look of the concrete while extending it's lifespan considerably.
Though new concrete may not always require a second coat of acid stain, older concrete does require two coats of stain for complete coverage. For a more diffuse look, spray the stain onto the surface without brushing.
Stains are effective in restoring glaze to dull, shabby concrete surfaces. Slabs with none to minimal cracks, blemishes, and other flaws are ideal for staining. Stains enhance the appearance of the surface; they don't conceal defects.
Bleach helps whiten the concrete, but is generally ineffective in removing the stain itself.
Muriatic acid: mix 3 to 4 parts water with 1 part acid, or follow label instructions for a 10% concentration (15% for hard, smooth concrete).
A true white color can only be achieved using a white cement mix. Add white concrete pigment to a gray concrete mix to create a sleek “ash” look that's popular in modern homes.
Adding too much muriatic acid can drop your pH levels too low. Low pH can cause eye irritation and skin rashes. It can also erode metals like pool ladders, railings, nuts and bolts, and other pool equipment.
Muriatic acid may damage concrete surfaces, so be careful when pouring it on sidewalks or driveways; new concrete typically does not need to be cleaned at all before applying staining agents. If you do pour some on these surfaces, rinse off with lots of water as soon as possible.