Making homemade acid stains for concrete

A. I am just starting with the process of mixing stains so I don't know much yet; when I get better I will be giving you a letter ASAP. What do these chemicals do for etching your iron and steel? have you tried mixing outside with chemical masks on. Make sure that you write everything, every little detail down; like if you mix hydro and sulfuric in .05% solutions measure and write it down. You never know, you might just come up with the ultimate Acid Stain that has ever hit the Market in both of our countries, and make Millions. It happens all of the time. Good Luck. Scotty

A. Try --
1 part hydrochloric acid,
8 parts water, and
5 kg ferrous sulphate.

This mix will produce a rusty colour in concrete.

A. HASSAN's recipe is a little bit wrong. Mixing and applying all together will result in a formation of insoluble calcium sulfate on concrete or marble surface. Hydrochloric acid is applied to the surface 10-15 minutes before. Then the sulfate iron solution. Once you do that the result will surprise you.
Of course the best formula is Ammonium Chloride, Iron Chloride and Water.
I tried the ferrous FeCl2 iron chloride (turquoise grains) and was really happy (the real rust colour shade).
I have not yet tried the FeCl3 that is marketed in the form of yellow grains.
I may get even better results though FeCl3 is used in a liquid form as copper remover

The tests were performed on marble surfaces. Why?

a) Calcium carbonate is also found in marble
b) Marble stain is popular in Greece

You can enter Greek characters in google search to see many photos.

I left the best for last. All our questions have been answered by Mr. SWIFT ERNEST since 1940 in his patent number US2379502A. You can download it online.

A. I am also trying to make acid stains on my own.

So far I have understood that there are 3 components. Acid (HCL/Sulphuric), Inorganic Metal Salts and water. Acids are used in less than 10% quantity. The salts used are ferrous sulphate(tan), copper sulphate(blackish) etc. I suggest experimenting with sulphates further to get colours. I also found that a solution of manganese chloride with sodium bicarbonate and acid is also giving results. Ferrous chloride and cupric chloride can also be experimented with.

Other than the stain, it is imperative to have a good sealer.

In case anyone else comes up with a formulation do let me know.

That is correct.
A. Any stronger than 10% acid will dissolve the cement cream that is required for the coloured surface and expose the aggregate.

As far as the metallic salts are concerned, keep adding and stirring until no more crystals dissolve, this is a saturated solution.

Add a squirt of detergent to the mix as a water softener to remove the surface tension, this will help the solution to penetrate better.

Hope this helps!

 Hi, cousins Ginger and Bozidar. Welcome!

Sorry, I have no knowledge of concrete staining to offer you; all I can do is coach people, based on having run the site for 18 years & counting, about improving the chance of getting answers. Asking no one in particular to forward exact formulas has not yet worked even once in a quarter million postings ... it's just a thread killer :-(

Please try hard to engage in a collaborative effort rather than a one-way technology transfer, and I'm quite confident that you'll get good help :-) Thanks!

Regards,

A. Ginger Martin:
There is a person in Leon Mexico with some non-commercial formulas for acid borne concrete stains. His name is Sr. Daniel Marquez of Leon, Gto. Mexico. Daniel is bilingual in English and Spanish. Daniel is knowledgeable concerning concrete. The knowledge he possess should move you beyond the experimentation stage of decorating with acid borne stains. In closing, never forget the acid borne stains are hazardous in their liquid state and you will need to protect your skin, eyes and avoid inhaling the fumes.

A. The inquiries I've read are interesting.

There are acid stains, non-acid stains, acrylic stains and concrete dyes. If you do begin making your own stains, be careful. Water first and acid or salts second in well ventilated area.

Have plenty of water on hand in case you get a splash in your eyes.
Some of the salts are poisonous if they penetrate the skin or by breathing.
You can actually lose your sense of smell if you breathe too much of this stuff.
I write manufacturing manuals on these products.
It is great to be able to make your own and save money, however, it can cost you much more.
Johnny

Excellent posting, Johnny, thanks!
Regards,

A. If you are looking for acid stain formulas and can't find them, you aren't looking hard enough. There are books on ebay and thru the search engines. They are not cheap, but hey, you are asking for a short cut.

A. I found the exact answer for this question at www.stainedfloor.com [DON'T DON'T DON'T go to that site!].

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Ed. note 2018: Sorry, that site presently bounces to a place that installs an Adobe "upgrade" (probably malware!). Ed note 2022: still malware, now disguised as an Apple help site :-(
Readers -- Please include title & author of articles you suggest (if not an abstract) when posting a link. Nearly all websites are short lived, and broken links are a contagion which then contaminate even long-enduring reference websites like ours. But worse! -- hackers often quickly buy up those links to put ransomware on your computer!

  Hi Babar. Please engage in the discussion, sharing your experience. Many readers would probably be interested in your efforts, successes, and failures in Pakistan -- I know I am. Thanks!

Regards,

A. I have found a very good walk-through of how to apply the stains: diystainedconcrete.com. Sorry no info on making the stain yet.

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Ed. note 2018, and 2022: Sorry, that site is long gone.
Readers -- Please try to include the title of an article if not an abstract when posting a link because most websites are short lived. With a title our readers at least know what article you want them to hunt for. Thanks!

A. For all measurement/homemade acid stain recipes take a look at this site.
www.stainedfloor.com/index.html [DON'T DON'T DON'T go to that site!]

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Ed. note 2018 &2021: That is a malware site!
Please try to include the title & author of an article if not an abstract when posting a link because most links are short lived. With a title our readers at least know what article you are suggesting that they hunt for. Thanks!

A. Hi, cousin Araz.

Metallic salts are compounds where a metal like iron or copper is compounded with an anion like acetate, chloride, nitrate, or sulphate. Some examples are copper nitrate [affil link], ferric nitrate, ferric chloride, ferrous sulphate, and cupric chloride. Yes, these are added to the HCl and water. Yes, these metallic salts are the source of the colors. Good luck!

Regards,

A. I had posted a response in 2006 and was surprised to see it still here. Metallic Salts are by-products of other products. Some can be liquid form, granular or powder. Examples are ferrous sulfate which can be used to make browns, terra cotta, tans; Then there's sodium dichromate combined with ferrous sulfate to make different shades of brown. Others salts are ferric chloride, manganese chloride, copper (cupric chloride) and chromic chloride. Different combinations of these salts mixed with a coagulant or activator like hydrochloric acid and water can result in several acid stain colors.

One of the best authors of how to apply them is Gaye Goodman. I write instructional manufacturing manuals on subjects like this one and others. My web address is www.concretesurfaces.com [ed.note: sorry, link is now broken]

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Ed. note: As the readers have come to expect, this fourth posted link out of four is now broken as well. Posters, please include the TITLE & Author of any article you are suggesting.

A. That's great, Araz! Very happy for your success, and good luck with the sales.

Regards,

A. Try using a clothing dye, I believe one brand is called Rit; mix with alcohol.
Works pretty well. Good luck!

A. I found this info posted by Mr Mathis of Macomb IL on a 'FineHomebuilding.com' page; it seems relevant to this conversation:

The original research and info provided by:
Mr Mathis, Macomb, IL

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Ed. note: Thanks Rocko!

A. 2 HCl + FeO = FeCl2 + H2O

Hydrochloric acid - approximately 74g
Ferrous Oxide - approximately 71g

Ferrous Chloride - approximately 127g
Water - approximately 18g

Adding more hydrochloric acid gives you an acid stain.

A. I am looking for acid stain formulas too. I found that the SDS sheets, safety data sheets, in PDF format for various commercial brands of acid stains show the ingredients and a formula. I don't know if the formula is by weight or percentages but it is a start. The metal salts are usually chlorides, plus hydrochloric acid which is muriatic acid, available inexpensively. I have ordered the metallic salts on Ebay.
I have a 7000 sq feet horrible looking floor with patches and stains to camouflage and at 200 to 400 sq ft coverage ft per gallon, commercial stain is out of the question.