How to Make Your Own Homemade Acid Concrete Stain

The cover photo that you are seeing in this topic, is about a big gazebo structure, that I designed and directed the construction works, but something more than that, the floor of that construction is made with acid stained concrete, beautiful right? but that stain is unique, and when I mean unique, I mean that I prepared the stain myself.

Why would I have to prepare the concrete stain? it is not easy to buy it? yes, I would have loved to buy the concrete stain and just apply them, but unfortunately, I live on a Caribbean island, and although it seems incredible, that kind of stain for concrete is not available here in any commercial establishment.

In short, to make a homemade acid stain for concrete, I did a lot of research and reverse-engineered the original product, the stain for concrete I prepared is composed of some sulfates, an organic acid-base, water, and flavoring to mitigate the odor, it is very easy to prepare, and I just mentioned the ingredients.

Now, I will go a little more into the processes, materials needed, some tips, and preparations so you can make your own acid-stained concrete floor.

Why did I have to prepare my own acid concrete floor?

I was working for a long time here in my country in an ecotourism project where the owners loved to use materials as organic and economical as possible.

One day in a meeting looking for alternatives for materials for new construction, one of the project managers presented me with pictures of what looked like a concrete floor with some very striking colors, it looked like marble, but obviously, it was not.

“That’s what I want for the floor!”, he exclaimed with an enthusiastic face…

As I was in charge of the construction and direction of the work, I started swimming in the deepest part of the internet looking for information about it, until I stumbled upon the name of the famous floor “acid stained concrete floor”.

Easy, I found the name and everything was easier, right? I just had to buy it, but here comes my big problem, the stain for concrete did not appear in any of the big hardware stores in the city, I immediately realized that it was something that did not exist in the country.

The administrator was still obsessed with the floor every day, I investigated on the internet how I could import a few gallons of the concrete acid stain, but there was another problem, the stain contained irritating and flammable materials and that is complicated to import.

I don’t know where I got the idea of preparing my concrete acid stain, but as it was just a gallon with color, I decided to take a look at its composition out of curiosity, until I finally could investigate the original components and I noticed that it was something very simple.

I know it’s a bit of a long story, but I’m not trying to fill up the topic, I just think it’s a bit funny, anyway I’ll give you the details here of how I managed to make the acid stain for concrete.

Discovering the components for my homemade concrete acid stain

At the beginning of the topic I practically put all the ingredients I used for the stain, but here I will explain them in more detail.

The first thing was to find out what was causing the color in the concrete, initially, I tried some things that in all honesty did not work for me.

In my search for the color, I had read on the internet that coffee could be used to stain the concrete, which I found interesting since I was really looking for a color tone similar to wood or coffee, but after several unsuccessful tests, I decided to give up on the coffee.

I am not a chemical engineer, I am an architect, I wanted to do something super simple, that would work, but above all that would not be dangerous, so I gave up using chemicals that were too dangerous to use for the creation of concrete stain.

In fact, I had trouble getting certain materials, since most of the chemical companies here did not sell retail or without a permit.

For the creation of the concrete stain, I focused on getting organic components, which were not dangerous to handle.

The truth is that I discovered that the sulfates were what caused the coloration in the concrete, it was a chemical reaction due to calcium hydroxide from the concrete when it came in contact with the sulfate, it reacted in a certain way that the colors emerged.

Sulfates are present in nature and are responsible for the colors formed in the soils, luckily, I discovered that I could buy sulfates locally and economically, but not in any chemical store or anything like that.

Sulfates were obtained in stores specialized in agronomic products, apparently, are used a lot in agriculture as fertilizers, next I will tell you the sulfates used and the colors they provide.

Ferrous sulfate monohydrate: this was the one I used the most, it gives reddish tones, if used very diluted it can give yellowish tones.

Copper Sulfate: there are two types of copper sulfate, one is a very fine and dry powder, and the other one is more humid, the first one did not work for me, the second one works for staining concrete.

The copper sulfate gives bluish tones with beautiful betas.

I tried to look for the sulfates on Amazon to share the links, but I didn’t find them, you have to look locally for stores that sell agronomy products and investigate if they have these sulfates.

Manganese sulfate: this was a fine powder, and unlike the other colors, the color of this powder was white, the manganese did not work for me directly applying it as a color to the concrete, but when I mixed it with the ferrous sulfate, it gave me beautiful dark brown colors.

So, maybe you know a lot about color theory, it’s something I master relatively well because of my studies as an architect.

You must be creative, the mixture of colors works the same with the sulfates I mentioned, if you want to achieve a greenish color, mix copper sulfate + diluted iron sulfate (blue + yellow = green).

By making color mixtures and diluting the colors you can get a considerable amount of concrete stain colors, I achieved 9 by testing, blue, brown, reddish, and green tones.

Discovering the acid component for concrete staining

Ok, I already had the sulfates that made the colors, but now I needed an acid component, the sulfates dissolved without problem in water, but if you put the water only, the mixture will not penetrate enough in the substrate and the stain would be very superficial.

That is why acid is necessary so that the stain can “open pores in the concrete”, I investigated that some people used hydrochloric acid, that acid is easy to get in any local hardware store, but as I said previously, I did not want to use anything that would be a danger to me or my family.

So I decided to look for another source of acid that was organic and easily accessible, I didn’t have to think much to get it, the acid I used for the stain was white vinegar, the most acidic I could get in the store.

So I prepared several samples with concrete slats, I made several tests mixing the sulfates in different proportions that I was writing down in a notebook assigning a name to the colors that were coming out.

I added a sufficient amount of white vinegar and I also added organic alcohol that I bought by the gallon, the alcohol serves to stabilize the mixture and also to spread the stain evenly.

White vinegar does not smell as strong as apple cider vinegar, but it still has a characteristic odor, so I bought a small bottle of a good-smelling essential oil, with a few drops the smell of vinegar is mitigated, and as a result, when applying the acid stain to the concrete it won’t smell like vinegar.

The essential oil I used was lavender, it was the best scent I could find, on Amazon I found them at a good price.

Additional equipment for applying the acid stain to the floor

The essential equipment to apply the dye to the floor is a pump sprayer, I got this equipment at a local store, and I bought a sprayer used in agriculture to spray plants.

This pump sprayer I found on Amazon does the job perfectly because you can carry it on your back and all its parts are plastic.

There are different sizes, ideally, buy one that you can carry on your back, so you can have both hands free.

Another aspect to take into account with these sprayers is to buy them with all the plastic elements, some of them have a metal tube, which is not good because, after a short time, they rust.

Apart from the sprayer, you will need special shoes to avoid leaving marks on the floor, initially, I bought sports shoes with rubber tips, the same ones used by those who play soccer or baseball.

Then it became very uncomfortable to use this type of shoes, but they are really necessary because you are going to be walking on the floor with the stain to make several passes, you are going to leave marks if you use conventional shoes.

Another aspect to keep in mind is to wear clothes that you are not going to need anymore, because the clothes you wear when applying the stain will be all stained, and there is no way to remove these stains, you can also use cloth gloves and safety glasses.

Shining the floor and a few more tips

The final part of my homemade concrete acid stain was the elegant touch, which consisted of making the floor look shiny, and believe me this was one of the hardest parts.

I researched several local products, remember I had to do everything with the materials I had locally, first I tried to gloss it with a floor sealer, it turned out that the sealer gave a little gloss, but it was not enough.

Then I decided to buy a high gloss clear epoxy, it was very shiny and enhanced the color of the concrete stain a lot, it was a change from heaven to earth, but I had a problem with the epoxy.

It turns out that the first job I did was on a very polished floor, the epoxy needs an “anchoring surface” therefore, a few days after the epoxy gloss, you could notice some white spots on the floor due to the epoxy “peeling off” in some parts of the floor.

I solved this by finding a high gloss floor varnish, the difference between the floor varnish and the epoxy is that the varnish is a single component, and the epoxy is two components that come together, in my experience, varnish worked much better for me.

For vertical surfaces such as walls where I used the acid stain, I used the sealer, on the floors I used the floor varnish and it worked well.

Some advice about problems I had, apart from not using epoxy, once I tried to apply the dye on a surface outdoors, and I did it at noon, the color of the floor did not look good because the dye evaporated too fast and did not react with the cement.

The idea is that you use the stain on a clean floor, free of grease, cement residues, etc etc, and also in a cool time where there is no direct sun.

Do not despair if you do not notice the color immediately, the chemical reaction usually lasts about half an hour before taking effect, at first when you apply the dye will give the impression of a wet floor and nothing more, the color emerges after a while.

The technique is to apply several coats of the stain, a first coat, and after the color begins to emerge apply another coat, always in the same direction, either vertically or horizontally.

If you want to mitigate the odor that is generated by the acid stain, either by the vinegar or by the sulfates, you can add a couple of drops of essential oil of your favorite scent and this works well.

Well, this was my story of how I was able to make a homemade acid concrete stain with success, I tried to create many other materials with organic elements, but this will be a matter of another topic.

Proportions I used for the mixtures of the concrete stain

For these mixtures I used plastic measuring spoons and also plastic measuring cups, the same ones used in the kitchen, you can find them in any commercial store, it is important that everything you use is made of plastic.

Color 1: Orange Blossom

21 ounces of ferrous sulfate per liter of H2O (water).

0.10 liters of alcohol per liter of H2O (do not apply alcohol to water, but the opposite, water to alcohol, I don’t remember why, but there is a reason).

0.20 liters of white vinegar per liter of H2O.

Color 2: Walnut

10 ounces of ferrous sulfate per liter of H2O (water).

8 oz. manganese per liter of H2O

0.10 liters of alcohol per liter of H2O (do not apply alcohol to water, but the opposite, water to alcohol, I don’t remember why, but there is a reason).

0.20 liters of white vinegar per liter of H2O.

Alcohol can be a bit expensive, it is not mandatory for the mixture, I used it only to further stabilize the contents of the mixture, but there were times when I prepared the stain without alcohol.

If you are going to apply scented essential oil to mitigate the odor of the vinegar, four or five drops is more than enough for one gallon of the stain, Good luck.