How to acid wash concrete with your own hands

Here are some important tips on how to apply acid stain to concrete floors or walls in a proper way.

Nowadays acid stain is commonly used for coloring concrete surfaces. Most acid dyes are liquid, so they flow down the walls being unable to soak in for a while, but there is a great solution to this problem – using modern gel-like acid stain for concrete. This article will help you to learn how to acid wash concrete with your own hands and how to apply acid stain to concrete floors or walls step-by-step.

You will need:

• protective glasses
• latex gloves
• to-throw-away clothes
• polyethylene film
• masking tape
• brushes
• sponges
• paint trays
• solvent
• baking soda
• a ladder

First and foremost you should choose your acid. Choose a product according to your level of experience and location of the project for cleaning or etching work. For example, sulfuric acid is the safest to use and it’s recommended for non-professionals. Phosphoric acid produces fewer pairs – so, use it in areas that contain stainless steel or other acid sensitive metals. It is also a good choice if you are just cleaning mineral deposits for your needs. Hydrochloric acid (muriatic acid) is the most dangerous one, because it produces a strong couple. It’s recommended only for those who work outdoors.

Concrete has to be treated properly before using acid, otherwise you will never be able to perform this type of work. To acid treated concrete you must follow the following technology.

1. Picking stains of desired colors

Acid stains for concrete are produced on the basis of natural minerals and stained concrete, changing its chemical composition. Colors of these dyes are still quite limited, but you can choose the color of some palette – from dark brown to green. It should be noticed, that color can be varied by mixing different colors or applying them in multiple layers. Remember that acid stains can not be used for stone, it can only change the color of cement. If the concrete rubble is added, the color can turn out, uneven.

2. Priming the surface

Treat you concrete surface with primer – it’s #1 rule. Otherwise, if your concrete surface has some remains of paint, varnish or glue, the walls will be painted unevenly.

3. Preparing the room

Remember that you are working with acid that can damage any surface it contacts. Therefore, it is necessary to protect the floor, ceiling, and all the wooden objects with films and other proper protection materials.

4. Putting on old clothes, rubber gloves and protective glasses

Acid stain can not only cause damage to your clothes, but it can also harm your skin and eyes. So, protect yourself properly.

5. Applying stain

Pour your stain in small portions into the tray and apply it onto the walls or floor with a brush or a sponge. If you need a single-colored wall, the entire surface should be evenly coated with some stain layers. One liter of acid can cover about 33 square feet of the concrete surface (depending on the porosity of the concrete). If you work with multiple colors, apply them so as to obtain the desired pattern.

6. Fixation time

According to the instructions on the package of acid, the fixation time typically varies between 2-8 hours. If the outer wall is painted, make sure that the surface is protected from the rain. After the complete drying the stain on the surface of concrete may form a white film. It can also change its color a little bit – this is quite normal.

7. Neutralizing

Use baking soda solution (1-2 spoons of baking soda to 4 liters of water) for neutralizing the acid. The solution is conveniently applied with a spray gun. Remove the excess with a sponge, for the solution not to flow down to the floor and damage it.

8. Cleaning

After neutralizing the acid coating, the concrete surface must be thoroughly washed with clean water – use a brush if necessary.

9. Complete drying

Allow the concrete to dry completely. It may take up to 24 hours.

10. Protection

You will need to apply a protective coating. If you work with inner walls, it is best to apply the water-based protective coating. Use sponge and apply it in several layers, allowing each layer to dry completely before applying the next one.

We hope this article has gave you the full information on how to apply acid stain to concrete floors or walls with your own hands in a proper way.