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Acid etching the garage floor is sometimes the only viable alternative for many DIY home owners when prepping concrete correctly to accept a coating. It isn’t hard to do, but certain safety precautions and steps need to be taken to insure a successful and safe outcome. Potentially dangerous if not done correctly, it can not only damage your concrete, it can cause serious bodily harm as well. So please take the time to learn how to acid etch your garage floor or concrete safely before jumping into your project head first.
Muriatic acid, also known as hydrochloric acid, is the typical acid of choice when etching concrete. It is inexpensive and a dangerous chemical that can damage almost anything it comes in contact with. It will eat through clothes, metal, skin, and creates a noxious vapor that can cause surrounding metals to rust as well as burn the lining in your nose and lungs. You can purchase it from your local home improvement center for less than $10 a gallon at a strength of 31.45%.
Phosphoric acid is a mineral acid that works almost as well and isn’t as dangerous to work with, but it is harder to find and more expensive. It also works at emulsifying oils – something that muriatic acid will not do. Both will remove rust from your concrete.
If you don’t like the idea of working with acid, you can read about some safer alternatives to acid etching here.
Supplies and protective gear for acid etching
- Hose with adjustable spray nozzle
- 5 gallon plastic bucket
- Plastic 2 gallon watering can
- Acid
- Baking soda
- Stir stick – wood paint stick works fine
- Push broom or long handled scrub brush
- Rubber gloves
- Rubber boots
- Splash safety eye goggles
- Approved respirator for working with acid fumes
- pH paper test strips
Acid is generally mixed at a ratio of 3 parts water to 1 part acid for sufficient strength to etch properly. Ideally you want to test the strength needed first before doing the entire floor. You can do this by first mixing a small solution in your watering can starting at a 5:1 ratio. Apply it to a small area of wet concrete. It should begin bubbling and fizzing immediately. If not then you will want to increase the strength accordingly. Sometimes a ratio stronger than 3:1 may be needed for particularly dense concrete or a smooth power troweled floor.
Caution! Always add acid to water, not water to acid. If you pour water into acid it can cause an explosive reaction that can spray you with the mixture and burn your skin!
Before acid etching, make sure the garage floor is cleaned properly of all oil, contaminants, grease, and dirt. Contrary to what many people think, acid will not clean grease and oil spots. In fact, if these areas have not been cleaned and degreased properly, the acid solution will just sit on top and not react with the concrete.
1 – Dampen the concrete:
Use your hose to lightly spray down the concrete in your garage so that the concrete is wet but not puddling water. If you have a large garage floor, you may want to acid etch in sections. Do not let the concrete dry out before or during application of the acid solution.
2 – Apply the acid solution:
Use the 2 gallon plastic watering container to sprinkle the acid solution on the concrete. This will spread the solution evenly without much splashing. Do not just pour it on the concrete. This will create an inconsistent spread of the acid solution and will not provide for a uniform result. The 2 gallon container works well because you can mix 1.5 gallons of water to .5 gallons of acid for a 3:1 ratio. However, you can use any size you like as long as you mix the ratio of acid to water correctly. 1 gallon of a 3:1 acid solution will cover approximately 50 – 70 square feet of garage floor.
3 – Scrub the acid solution:
Once the solution is applied, lightly scrub it into the concrete with a push broom or long handled scrub brush. This helps to create a uniform etch of the concrete. Let the solution sit for 10 – 15 minutes while it continues to fizz and bubble. Do not let the floor dry out during this process. Add more solution if necessary.
4 – Neutralize:
Mix 1 cup of baking soda to 1 gallon of water in your large 5 gallon bucket and pour it into the now empty watering container. Sprinkle your neutralizing solution over the part of garage floor that was acid etched and let it sit for a minimum of 10 minutes. When time is up, rinse the neutralized solution with your hose into a drain or out the garage (if local water codes allow it). Another method is to use a wet vac and then dispose of the solution according to your local codes.
Check the surface of the concrete at this time. It should feel similar to medium grit sand paper with a uniform texture. If not, you will need to repeat the process again.
5 – Final rinse:
Once the initial neutralizing solution is cleaned up, it is important to thoroughly flush and rinse the remaining solution out of the concrete. You may need to do this multiple times. It will leave a white powdery residue (calcium carbonate) on your garage floor once dried if you do not do this. This is a fine white dust that will not allow your coating to adhere properly. Use a high pressure nozzle while thoroughly scrubbing the concrete with your scrub brush. You can introduce a mild solution of Simple Green at this point if you like. Just make sure it is thoroughly rinsed.
Using a pressure washer for this process works well also. Do not use a pressure washer to rinse off the initial neutralizing solution. It can drive any acid solution that had not been neutralized deeper into the concrete and cause problems later.
6 – pH test your rinse water:
After your final rinse, dab a pH test strip like these at Amazon onto the still wet garage floor to check the pH. Anything between 6.0 and 9.0 will work for most coatings with 7.0 (neutral) being ideal. If it’s below 6.0 then the water is indicating that acid residue is still in the pores of the concrete. Rinse some more and repeat the test until you get the results you want.
Further Tips for Acid Etching Concrete
It’s a good idea to cover anything in your garage that you don’t want to get splashed with a plastic drop cloth. Another recommendation is to mix some neutralizing solution up ahead of time and spread it out liberally on your driveway. That way any acid solution that is hosed out will not mildly etch or discolor your driveway. Don’t acid etch the concrete if the temps are below 50 degrees as the acid will not be as effective with the cooler temperatures.
Also, make sure your garage floor has dried thoroughly before applying epoxy coatings. Fans will help. Give it at least two days with warm weather and longer if it’s humid or cooler. Though the surface may be dry, the pores of the concrete can still contain moisture and escape through outgassing when the temperatures rise during the day. This will cause your coating to form bubbles. You can always do a quick moisture test with plastic if you are not sure.
Learning how to acid etch your garage floor isn’t hard, but it’s very important to follow the proper steps. When done correctly, the chances of having your coating fail due to improper preparation of the concrete is reduced significantly.
Karen says
I bought a cottage and it appears the garage floor was started but never finished, meaning, the powder garage floor looks like someone put baby powder all over it. The floor has places that the gravel used in the concrete seems exposed. Can I just vacuum or sweep this powder up and paint the floor? Do I have to wash it down? I can’t afford to pay someone to do this so I want to try it myself.
Shea says
Hi Karen. It sounds like you have a sandy top that may be deteriorating. This is usually caused from too much water being used on the surface when it was finished. The result is a weak top layer that breaks down and turns to dust or powder. Sweep the floor first then clean it with soap and water. Let it dry and see if the powder comes back in a couple of weeks or so. If it doesn’t, then you can prep the floor for inexpensive painting. If the powder comes back you will not be able to paint or coat the floor because nothing will stick to it. Your only option then is to save your money to resurface it or use a floor covering like mats or interlocking garage tiles.
John K. says
Hey,
I have a large auto repair shop that we just bought which is around 10k sq.ft. and I would like to try DIY sealer and coating product that has large coverage will be able to apply for such a large area and which will leave the surface looking somewhat new and reduce spills from staining. Can you assist as there are so many choices that the only thing I can decide is I don’t want expoxy as it’s too expensive and costly to do. ?
Thanks
Shea says
Hi John. Unfortunately for what you need, a quality resinous coating such as epoxy, polyurea, or polyaspartic is the only type that will renew the look of the floor and provide the type of protection that you need for an auto repair shop. The cheap one coat products offered by the home improvement centers will only look beat up in a short while when subjected to that type of environment. 10k sq.ft. is a lot of floor to cover! For that much floor you can most likely get a quantity discount from a good floor coating vendor, but your still most likely looking at a minimum of $5,000 in materials and that doesn’t include floor prep and supplies.
If you don’t mind the look of the bare concrete, you may want to read about this product here or even this one here. They will both help the reduction of staining and easier floor cleanup and price much less than an epoxy coating.
Kyle says
Hi, I finally have my epoxymaster kit and im ready to get into applying it in a week or so. I will be going the acid etch route. It’s going on a brand new non-sealed concrete garage floor with no joints or anything.
Do you always recommend diluting the acid?
For spreading the acid, is the watering container you use like the all plastic units used with pesticide spray?
I had our builder pressure wash the garage after the construction was done to clean off anything that may have contaminated the floor, but i still think ill use a hose and a deck brush to scrub it again to make sure.
Thanks!
Shea says
Hi Kyle. Yes, diluting the acid properly is very important. Straight acid will damage the surface of the concrete. It can make the surface soft and create an abundance of calcium phosphate (white powder) that is hard to remove. Use a cheap 2 gallon watering can for flowers and flood the surface with the acid solution. Do not let the solution or any of the floor dry out until you are completely done with the process. Neutralizing afterwards and rinsing the floor thoroughly is very important as well.
ERICK says
MY WIFE DUMPED STRAIGHT MURIATIC ACID ONTO FLOOR OF GARAGE. IT TURNED YELLOW, SHE BROOMED IT AROUND AND THEN RINSED WITH WATER. THE FLOOR AND AREA THAT SHE SPLASHED QUICKLY TURNED WHITE WHEN SURFACE STARTED TO DRY, ANY SUGGESTIONS?
Shea says
Straight muriatic acid can damage concrete Erick. The best you can do is neutralize the area with 1 cup baking soda to 1 gallon water. Pour it onto the area and scrub it with a short bristle brush or deck brush. Let it set for a few minutes and then rinse liberally with water. It may take multiple fresh water rinses to remove the white residue.
Tom says
So I made the mistake of pressure washing the acid in the attempt to rise it off. Now I keep getting fine dust when trying to sweep it away. What can I do? Thank yiu
Shea says
Hello Tom. Rinse, rinse, and rinse again. Most of it will come up. It usually helps to mix up some TSP and scrub the concrete with a deck brush. Do not let anything dry and then rinse again.
CajunPatriot says
We are currently working on a large area of concrete with has a slick finish, but is not soiled with oil or anything else. We have pressure washed and scrubbed it well, and have applied a 1:2 ratio of muriatic acid and water. We scrubbed the concrete with the foaming acid-water mixture and waited 15 minutes to rinse it off and scrub it again and rinse it again and again.
This is our first defined area of concrete preparation for a patio room which we are working on to host the local high school students who volunteer at the local nursing homes and for local charities like the Leukemia & Lymphoma Society.
We will stain the floor with six different pastel colors fading into one another and blending and then seal the floor twice. Our carpenters are coming on Tuesday to build exterior walls and erect a bathroom and we will work on getting the plumbing connected and all the rest over the next few weeks.
Shea says
Wow.. sounds like quite the project. Good job!
Jon B. says
Can acid etching remove old paint from the concrete? The previous owners of my home painted one of the 3 car garage sections and it already has hot tire pickup (not surprised) and is beginning to already peel up by just pressure washing…will it be possible to just acid etch this off? The local Tool rental shop has the grinding tools rented out…..
Shea says
Hello Jon. No, acid etching will not remove the paint. It just makes for a semi gooey mess that doesn’t do much. Acid needs to react with the free lime in concrete in order to work properly. Paint stripper or grinding is the way to do it. Sometimes a pressure washer will remove it as well.
Jonathan Iagulli says
Is it necessary to pressure wash a garage floor of a new construction home prior to etching? There are of course no stains or noticeable issues with the concrete.
Shea says
No, it’s not necessary Jonathan. As long as there is no grease or ground in dirt that would block the acid etch, all you need to do is sweep up the loose debris and then follow the steps for acid etching.
Don says
Concrete floor, already etched and painted 15 years ago. All seemed OK.
Now, numerous small areas (size of a dime) are beginning to appear, due to the humidity pressure of the water table under the concrete floor.
The paint forms bubbles, which are filled with a white powder.
What to do?
Shea says
Hello Don. You obviously have moisture in the slab that is traveling up to the surface. It’s bringing water soluble salts from within the concrete that evaporate at the surface leaving the white residue. If the slab just started this after being fine for 15 years, then something has changed that is causing the moisture in the slab. You could have a leaky pipe underneath, poor drainage around the slab, or maybe a broken downspout as an example. We recommend finding and addressing that issue first before moving on to the floor. Once you do that, you will need to grind the concrete to remove the paint and then conduct a moisture test to see if you solved the issue or not. It may take a few weeks for the moisture to completely work its way out. If you still have some moisture you do have some options. You could apply a penetrating sealer to stop the moisture and protect the concrete. There is also the option of applying a moisture barrier coating if you want an epoxy floor.
Don says
Let me clarify…
My concrete floor is in my basement, which is 6′ below grade.
All around our house is a weeping tile system, which is 50 years old.
It is possible that this is the problem.
To my knowledge, there are 2 ways to inspect this. One is to dig a 6′ trench around the outside of my house and physically look at the weeping tiles. The other is to dig a single 6′ deep hole and insert a remote-control video camera into the weeping tile system. Option #1 could cost $25K. Option #2 about $5K.
If I do option #1, it makes sense to replace the entire system, while the trench is dug.
Shea says
OK, Don. That makes sense as to why you suddenly are having this issue. If you have a problem with the weeping tile system not draining the water away properly, the floor is going to be the first to so show signs of the moisture, followed later by the walls if it gets worse. We aren’t really in a place to make recommendations for this type of repair, but we believe you are approaching the issue correctly. Get the drainage fixed first, then worry about the floor. If you are not doing this yourself, be sure to get more than one opinion and quote. Once you get the issue corrected, it will most likely take a few weeks for the concrete to dry out. Running a dehumidifier in the basement along with a fan over the concrete will help speed things up.
Don says
One more question…
99% of my basement concrete floor is painted and is perfect.
I probably have 100 small effervescence spots which I would like to clean and repaint.
One home store advises me to clean it with CLR using a toothbrush, then rinse with water, then re-etch, then paint.
Another says “don’t waste your time” as it will be 20 years before I will have a real problem.
Any ideas?
Shea says
Well, you really won’t know Don until you do it. If it stays fine for a few years at a time then I would say it’s worth it. If it bubbles up within a couple months, then the problem will only get worse as time goes by. It’s not a big deal really to do paint touch-up. Epoxy is another matter however.
Steve says
Our garage floor was finished extremely smoothly – such that it is dangerously slippery when wet.
Would etching with acid be a good method to improve traction? I don’t plan to apply a coating unless I have to.
Thanks!
Shea says
Yes, acid etching will open up the pores and make it less slippery Steve. However, it will also make the concrete much more susceptible to staining and harder to clean if left untreated. We recommend applying a penetrating sealer after you acid etch. They are inexpensive, easy to apply, and they will not change the look or grip of the bare concrete. Here is a good example of penetrating sealer we would recommend.
Steve says
Thanks Shea! Will read over the sealer info & figure out a game plan. Preferably before someone breaks their neck! ;^)
Amy says
I have a large concrete porch that was painted with cheap walmart paint approx 15 yrs ago. we were able to get most the paint off with a power washer, we did the etching process and there are some paint specks left that we plan to sand/grind off. after that we plan to use behr concrete dye with 2 contasting colors and seal. think it will work>
Shea says
That should work well Amy. Seal it with an acrylic coating and it will make the dye color pop!
Sean says
I just purchased a house and am considering applying a paint or possibly an epoxy coating to the garage floor. There are some medium-small sized cracks in the concrete (none more than 1/4″ wide) that I am also interested in filling in (my OCD will go crazy if any of them telegraph through), but I am unsure of the proper process. If I fill them in with an epoxy crack filler, I assume that acid etching should be done first… In other words I am unsure of how acid etching would react with any epoxy products on the floor. Any recommendations? Thanks!
Shea says
Acid etching is not going to affect your repairs Sean. Acid works on the lime in bare concrete and has no effect on epoxy, polyurea, or polyurethane repair products. Do your repairs first then profile the surface with an acid etch or grinding.
Edward John Franks says
Hi Shea, thanks for all the awesome advice. We have a garage we are turning in to a studio and we’re planning on painting the floors w/ white epoxy and a sealer. We are not planning on putting a car in the garage nor do I think that the previous owner ever had a car in there as well. Time is a luxury we do not have. Is it absolutely necessary that we etch and if we do, what is the absolute minimum drying time? We are down in Orlando FL and have been enjoying slightly cooler weather but gets somewhat humid during the day.
Thank you.
R/
Edward-John Franks
Shea says
Hello Edward. Yes, you need to etch at the minimum when applying epoxy. Grinding is an option as well. However, what we suggest Edward is that you look at a product called Rust Bullet. We did a very informative article on it here. As long as there was not a sealer applied to the floor previously, Rust Bullet can be applied to a clean concrete floor without having to etch or grind. They actually make a glossy white that can be applied over an initial coating of their standard gray. It has been used for both art studios and photo studios as well as garages.
Ruben says
I have a concrete floor that I want to etch. My septic tank (concrete) is brand new and does not yet have water in it. Will it be okay to wash the solution down the floor drain into the new tank after etching or will it hurt the concrete in my new septic tank?
Shea says
If you are using muriatic acid Ruben, be sure to neutralize it well before rinsing it off the slab and down the drain. If you are using something provided in a kit, chances are it’s a less aggressive citrus based etch that is biodegradable and does not need to be neutralized. Just read the package to verify first.
Carolyn Wellman says
We have a room that was converted from a carport to a living room before we moved in. We had some water seepage from where the foundation wall meets the concrete floor that we repaired. I want to remove the carpet which we had to cut away from the wall the fix the seepage and would like to stain the floor and seal it–do I have to etch the floor to do this? Reason I am asking is because this is in a space of the house we use as our living room with furniture and I don’t want to get the etching stuff on my walls plus I am worried about the harmful effects the chemicals do. I really need help because I am so lost right now. Thank you!
Shea says
Hello Carolyn. Have you tested the concrete yet to make sure it doesn’t have a sealer? This article explains how to do that. Assuming that the concrete does not have a sealer on it you will not have to etch the concrete. However, the type of sealer you want to apply can be dependent on an acid etch or grinding (profiling of the surface). If you go with an acrylic sealer then you will not need any additional concrete prep. If you go with an epoxy, polyurethane, or polyurea sealer, then you will need to profile the concrete surface first.
John V says
Shea:
I want to do a metallic epoxy project in a living room and bedroom where I can’t use the large volumes of water one could use in an outdoor or garage project. Do you have any tips to accomplish the etching process in an indoor environment? Thanks!
Shea says
A grinder with a good dust shield and proper vacuum attachment is what most installers use John. You will get some dust, but nothing heavy. If that is not an option, then we suggest you read this article that highlights Eco-Etch Pro. You can etch the concrete with minimal water and a good wet/dry vacuum with the proper water attachment.
Andrea says
Shea, I just want to thank you for the awesome article and for taking the time to answer everyone’s questions. I was going to dive in and do the muriatic acid (our garage smells like the feral cat spray from the former owners) but read in your reply to another person that if there’s paint already on the floor (or epoxy) that grinding is the way to go. I’ll learn that next part now. Thank you again!
Shea says
You’re welcome Andrea!
Barb says
I made the mistake of putting muratic acid directly on the garage floor – now it is extremely spotted where I poured the solution. Thankfully I rinsed, rinsed and rinsed the floor many times. Now I am debating if I should buy more and dilute it to get the floor looking better. I really don’t have intentions of painting the floor – it is just so dirty and stained from the previous home owners. Any suggestions?
Shea says
Hello Barb. You have the right idea. If you have not done it already, we suggest cleaning and scrubbing the concrete real well with a degreaser first. Acid does not work on grease or heavily soiled areas since it only reacts with bare concrete that is mostly clean. After the concrete surface is clean you can then acid etch the surface. It will lighten the concrete up some and help to blend in the spotted areas. We have an article on how to acid etch here. After that, we suggest applying a penetrating sealer to protect the concrete. The acid etching opens up the pores and the concrete will act like a sponge and dirt magnet unless you seal it afterwards. Penetrating sealers are inexpensive and easy to apply. We would recommend this type here.
Bob F. says
The only muriatic acid available to me for cleaning concrete is from Lowes and is described as “Hydrochloric acid, 20 percent baume© (31.45%).” Does this “normally” require even more dilution with water, as you described in this article?
Shea says
Hi Bob. Yes, that is the one. You can’t buy muriatic acid diluted for concrete. That is why we state the appropriate mix ratios. Remember, acid does not “clean” concrete. That is a misperception due to the whitening effect that acid etching has on concrete. If you have very dirty areas or oily areas it will not work well. Oil and dirt repel the liquid solution and will not let the acid come in contact with the free lime in the concrete that it reacts with. Make sure the concrete is as clean as you can get it before you etch.
Bob F says
OK Shea, thanks, your are a great help. My main question, not well stated, is whether or not I need to do further dilution of the 31.45% Cleaner that I described from Lowes.
Since you said that one might start with a mix of 1 part acid per 5 parts of water, I assume that is equivalent to about 1/6 = 17% dilution. I think that is close to some of the so-called “green” mixtures that are available off the shelf. So I would need to add water to bring the as-purchased solution down from the 31.45% stated on the bottle to about 17% — before applying it to the concrete … or maybe better stated for safety .. add the as purchased solution to water; am I looking at this correctly?
Shea says
You have the right idea Bob. We answered this question for you here where you first posted it. You will find it near the bottom of the page.
Rachel says
Hi
We have a 24/7 Gym and we are looking at ripping up the carpet and putting the epoxy flooring in. The concrete looks fairly clean except from the adhesive used on the carpet, what would you advise to clean the concrete the etching or grinding. I read one of your previous comments that etching can cause rust in metal and since all of the equipment is metal it is a concern for us but this is the cheaper option.
Would appreciate any advice you have.
Shea says
Hello Rachel. Grinding would be the best option. Since you have glue residue on the concrete acid will not work until you clean all the glue residue off. This can be a laborious task that requires liquid chemicals. The eco-friendly biodegradable products like Bean-a-Doo work well, but they take time. Grinding will remove the glue residue and prep the concrete at the same time. While grinding can easily be completed in a day (providing you have less than 1000 sf), the process of removing the glue and acid etching will take a few days not including the time required for the concrete to dry thoroughly before you apply a coating.
One thing to keep in mind about concrete coatings are that they can be slippery when they get wet. Sweat and spilled water bottles can create a safety hazard. Also, coatings will not stand up to repeated abuse of dropped weights no matter how tough the coating is.
Tyler Demas says
Hey there!! I’ve been reading these articles for hours, they’re absolutely wonderful. I’ve been searching for a direct answer to my question and couldn’t find anything specific enough to make me confident moving forward. My situation is this: I used some Seal-Krete garage floor paint and color flakes to paint half of my two car garage. I say half because I realized after half of the garage being painted that this was not the shiny epoxy finish I wanted. My question is how would I prepare the painted and color flaked half of my garage for a two part epoxy coating, and also, there’s small cracks running through the cement on both sides that seem to be retaining moisture, can I just use some sort of sealant and epoxy over it? And will I need to etch the bare cement half of my garage that hasn’t been painted? I’ve already scrubbed it with degreaser and a deck brush, just not sure where to go from here. I’m worried the two sides will look different when I’m finished. Thanks for the help!!
Shea says
Hello Tyler. We answered much of your first question in the other article regarding the cracks and lack of shine here. Yes, if you do the other half of your garage with a high quality epoxy it will look much different than the first half that was painted. You need to etch or grind the bare concrete if you want to apply an epoxy coating or something similar such as single-part polyurea. As we said before, we recommend that you just paint the rest of garage floor to match. Then, when a good quality product is in your budget you can grind the paint off and apply a good coating system that will last for years. Grinding the paint off the concrete will prep it as well. The other option if it’s in your budget would be to grind the entire garage floor now and apply a good coating system.
Brian says
We are building a new building. Brand new concrete. Is it necessary to acid etch before applying apoxy sealer. Could we just use a buffer with a good pad? Clean it really good then seal. We have metal framing and I’m concerned about the acid getting under the walls and coming in contact with the metal. Also, walls have been newly painted and I don’t want to damage the new walls.
Shea says
Hello Brian. Yes, it is absolutely necessary to properly profile the surface of the concrete before applying epoxy. New concrete is freshly troweled and effectively blocks the pores for epoxy penetration. Grinding the surface is the other option and the most preferred for the best concrete prep. There are also alternatives to acid etching. Buffing the concrete will have no effect. Concrete is extremely hard and a buffing pad will not do anything.
Bart says
Hi again!
I etched my three month old concrete floor today with phosphoric acid. Finally, after rinsing for what seemed like hours, I notice that the floor is still fairly smooth to the touch.
Having said that, the contraction joints I filled (Legacy Xtreme-100) and ground with a 6″ diamond grinder are only slightly more rough. Plus, the whole surface absorbs water like a boss.
I feel quite confident that it will absorb primer for my Nohr-S system. How confident do *you* feel about this? I really don’t want to go through the trouble of renting and using a grinder, or the potential horror of muriatic acid…
Many thanks again,
Bart
Shea says
If it’s absorbing water that well, Brad, you should be just fine – especially since you are using a primer.
Bart says
Thank you for holding my hand through this process. I will not hold you to your words, but I appreciate the technical and moral support 😀
Shea says
Thanks, Bart. It’s one of the reasons we started our website. There just isn’t much good information available about garage flooring in general, particularly coatings. Good luck!
Jeremy says
Hello,
I acid etched with good result following the procedures outlined above. I neutralized, rinsed and scrubbed multiple times. Now I’m getting white/yellowish residue/powder built up on the floor (calcium carbonate I assume). It comes off with a pressure washer but the nozzle on the pressure washer is small and basically the entire floor is caked with it. It is hard to tell where it is on the floor once it/s wet. Is there another way to effectively and efficiently remove the buildup?
thanks!
Shea says
Hi Jeremy. Sometimes this can happen depending on the concrete and/or how long it sat before being rinsed. A pressure washer will usually remove it, but it takes some work. We have had luck in the past with wetting the floor real well one section at a time and then applying the inexpensive citric etch that you can get from home improvement center. Since it does not have to be neutralized, you can scrub the concrete with that to help lift the residue and then immediately rinse that section well with a high pressure nozzle on your hose.
Rohit k says
Hello, Thanks for your help in answeing so many questions. My house is 20 years old. I want to do epoxy on the garage floor. I have cleaned and scrubed floor with dish washing liquid twice, degreased, scrubbed floor thorougly with metallic bristles brush, and etched with citric acid that came with the kit. The mistake i did was to mix only one pouch of citric acid powder ( instead of two supplied with the kit) in 2 gallons of water and scrubed throughly. Later i realized there was one more citric acid pouch in the kit. So basically i used very diluted acid by mistake. I again etched the floor using that remaining pouch but this time mixing with one gallon of water but this time acid ( just one gallon) was not enough for the entire 2 car garage. I did spread it as best as i could with the brush though. My question is should I etch with proper amount and proper strength? Or am I good to do epoxy coating now. Thanks a lot in advance
Shea says
Hi Rohit. It sounds like you are using a typical DIY epoxy paint kit. If so, do a water test on a few areas of the floor. Pour a tablespoon or two of water on the concrete. If the concrete immediately turns dark and absorbs the water, then you should be OK for the coating. If it doesn’t turn dark right away or it takes a few minutes for the concrete to absorb the water, then you have more etching to do.
Rohit says
It turns dark right away, water absorption is slower in certain places but definitely not like water floating on latex painted surface. I wish if I could add any photos here. Thanks a lot for your time. Really appreciated
Jeff says
I powerwashed the concrete floor and scrubbed decreaser.
After giving it 3 days to dry, I grinded the floor with a concerete turbo ginding wheel. It took me about 5 hours to grind the floor. I get that I could have done this alot faster by renting a big one from homedepot but I am on a budget so I figured I’d just put in the time. Doing this kicked up a tremendous amount of dust. here is the grinder I used
https://www.amazon.com/OCR-Concrete-Diamond-Grinding-Grinder/dp/B01CQQR3DW/ref=sr_1_3?ie=UTF8&qid=1532573798&sr=8-3&keywords=diamond+wheel+grinder
After grinding, i rinsed with the power washer.
The conrete was still smoth. Maybe it felt like a really fine grit sand paper but certainly not medium grit.
So I decided to acid wash.
3:1 water to muratic acid mixture. Fissed up and bubbled no problem so there clearly is no selear.
I did a second acid wash. Scrubbing it into the floor with a deck brush.
Finally I rinsed clean with water and baking soda.
The concrete still feels smooth. The acid wash fissed up really good and released a white gas so I know it’s working but after rinsing and drying it’s almost as if the concrete is the exact same as before the acid wash.
Thoughts?
Shea says
Hi Jeff. Wow…. you went way overboard on the pep. Grinding with the turbo cup wheel should have been enough. Hopefully the two acid etches afterwords didn’t weaken the surface. Once you grind, all you need to do is a small water test. If the surface will immediately turn dark and absorb a tablespoon of water within 30 seconds you are good to go.