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 it 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 in a caribbean island, and although it seems incredible, that kind of dyes for concrete are not available here in any commercial establishment.
In short, to make an homemade acid stain for concrete, I did a lot of research and reverse engineered the original product, the dye 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 a 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 dye 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 dye 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 dye, 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.
In fact, I had trouble getting certain materials, since most of the chemical companies here did not sell retail or without a permit.
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 that are 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.
The sulfates I got them in specialized stores for agronomical products, apparently they 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.
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.
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 dye would be very superficial.
That is why an acid is necessary, so that the stain can “open pores in the concrete”, I investigated that some people used hydrochloric acid as an 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 acid 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 dye evenly.
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 my first job I did was on a very polished floor, the epoxy needs “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, 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 ideal is that you use the dye on a clean floor, free of grease, cement residues, ect ect, 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 dye, a first coat, and after the color begins to emerge apply another coat, always in the same direction, either vertically or horizontally.
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.