do you have to acid etch concrete before staining

by Cleveland Volkman IV Published 2 years ago Updated 2 years ago

Schmidt also warns against acid etching of floors before staining. A lot of people think they need to acid etch the concrete like they do before applying a paint or coating, to get the paint to adhere. But acid washing depletes the lime content, which is what the minerals in the acid stain react with.

Full Answer

Can you use etching acid to clean concrete?

Etching acids can't penetrate through oily substances, which means that any concrete under an oil stain will go un-etched. To remove oil and grease stains, try scrubbing with a commercial degreasing product — these are available from most home improvement stores for fairly cheap. Alternatively, try using ordinary laundry detergent.

Do you have to wet concrete before etching?

The concrete should stay at this level of wetness until the acid is applied. If you'll be etching up to any adjacent walls or other surfaces, be sure to also wet the bottom inch or so to minimize the possibility of direct contact with the acid. Mix water and acid in 3 or 4:1 ratio. Add clean, clear water to a plastic bucket.

What are acid stains on concrete?

Unlike paints and coatings for concrete, which are opaque and can disguise many evils, acid stains are transparent. Any unwanted residue remaining on the floor is likely to show through the newly applied stain. Any materials that inhibit concrete stain penetration, such as grease, oil, or curing membranes, will prevent the color from taking.

What is acid etching?

Acid etching is a great way of removing thin layers of laitance before applying paint. Efflorescence is similar to laitance in that it is a build-up of chalk-like substances on newly installed concrete. Instead of containing sand and concrete particles, it contains salts.

What happens if you don’t etch concrete before epoxy?

How long does concrete need to dry after etching?

Is etching concrete necessary?

Can you seal concrete without etching?

Does vinegar etch concrete?

Does concrete stain easily?

Is it better to paint or stain concrete?

See 2 more

Can you stain concrete without acid?

0:283:09How To Stain Concrete Without Using Acid - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo what we're going to do is we're going to etch it rough it up then we're going to neutralize it.MoreSo what we're going to do is we're going to etch it rough it up then we're going to neutralize it. And then stain it first up is the etching. We're using a biodegradable.

Is concrete etching necessary?

Etching is a crucial step in preparing concrete for painting. It gives the surface tooth to adhere to, so your paint is more likely to stick for a long time. Most concrete paints require etching and if they don't, do it anyway. Don't skip this step if you want a long-lasting painted concrete floor.

How do you prep concrete for staining?

Strip and remove all previous sealers, paints, adhesives and coatings. For oil spots use a degreaser and neutralizer (diluted 4 to 1) and rinse well. For acid staining, use a concrete etch and cleaner to prepare the surface and rinse well. Concrete must be porous enough to accept water.

How long after etching concrete can you stain?

Allow the surface to dry completely before applying any coatings, paints, stains or sealers. Two gallons of mixed etching solution will cover up to 500 square feet. Allow to dry for 24 hours before staining, sealing or coating.

What happens if you dont etch concrete?

If you choose to skip the etching step before applying the paint, the paint may bubble up, peel or flake off the concrete, especially on smoothly finished surfaces, leaving the surface more unsightly than before you painted.

Does vinegar etch concrete?

Etching – Vinegar's ability to dissolve CaCO3 will dull your marble, travertine, concrete and terrazzo surfaces. It may “clean” the surface but it is also dissolving pits into the finish and effectively dulling it.

Do you need to prep concrete before staining?

Concrete can look strikingly professional and luxurious with the right stain. But before you apply a stain, you need to prep the floor thoroughly for staining. An effective stain starts with a clean and clear surface. If you don't, you'll be left with floors that are irreversibly marked and damaged.

Do I need to prime concrete before staining?

Prime the surface with a primer that is compatible with the stain. For best coverage, roll on the primer with a 3/8-inch nap paint roller and follow all manufacturer's guidelines for mixing and curing.

How do you know if concrete is etched enough?

In addition to the water test, feel the surface of the concrete — a properly etched concrete surface should look and feel like 120-grit medium sandpaper. If it is properly etched, your surface is now ready for you to apply your sealant or coating.

Do I need to seal concrete after staining?

To prolong stain life, stain manufacturers recommend keeping stained surfaces protected with multiple coats of clear sealer (outdoors) and a floor wax (indoors). A good sealer will provide other benefits as well, such as adding sheen to the surface and enhancing color intensity.

How do you remove etching residue from concrete?

If available, use a squeegee to remove the etching solution before rinsing. Otherwise, rinse using plenty of water. Scrub the surface while rinsing to insure complete removal of the etching solution. Move to an adjacent area and repeat the process.

How long do you rinse after etching?

Typically, enamel and dentin are etched for 15 seconds. Some products recommend etching enamel for 20-30 seconds and dentin for 15-20 seconds. Rinsing for 15 seconds is necessary to remove the residue of phosphoric acid and smear layer.

Should you etch stamped concrete?

Most concrete contractors are no longer recommending acid etching because of its effect on health and the environment. Instead of etching, sandblasting or grinding is a great way to remove any contaminants on the surface of the concrete slab and to open its pores as well.

Should new concrete be etched before sealing?

The short answer is: Yes, even new concrete needs to be etched before applying epoxy or a similar type of garage floor coating. Etching is part of the concrete preparation process. In fact, proper preparation of the concrete before a coating is applied is the most important part.

Do I need to acid etch after grinding?

Acid versus Grinding Under ideal circumstances, acid etching works to expose the pores of the concrete. However, acid etching won't remove glues, mastics, caulk, and common stains, If your floor is marred or stained by these substances, you'll need to resort to grinding at least part of your floor.

Can I just paint my concrete floor?

You can refresh the entire space by painting your concrete floors. In combination with the right tools and techniques, today's masonry paints, designed specifically for concrete, make it easy to turn a drab concrete floor into an attractive surface that can complement a variety of spaces, both indoors and out.

How long does it take to stain concrete?

Staining concrete is a great way to add color to an otherwise dull surface. The concrete staining process takes about 2 days, is moderately difficult and fairly affordable. New concrete should be fully cured before staining, which takes between 21 and 28 days.

What is the difference between concrete stain and concrete paint?

Concrete stain embeds the surface to color it translucently, while opaque concrete paint covers the top of the concrete but is subject to chipping and peeling when improperly applied. Concrete stains go on quicker, dry faster and take less work than concrete paint, but they offer no significant protection.

What chemicals are used to clean concrete before painting?

In most cases, special cleaning and/or etching of the concrete surface will be required before painting, and the appropriate cleaner (often TSP, trisodium phosphate) and etcher (usually a solution of muriatic acid) can be obtained. These chemicals, especially the etcher, must be used with care.

How long does it take for etching solution to dry?

Two gallons of mixed etching solution will cover up to 500 square feet. Allow to dry for 24 hours before staining, sealing or coating.

Can you etch concrete with sealer?

But etching products work only if the concrete is clean and not already coated. You could easily spot paint if the concrete were coated with that, but sealer, which would also keep paint from sticking, might be invisible. One way to test for sealer is to pour on some water.

Can a stain be removed from concrete?

Stains are non-film forming. They do not seal the concrete nor do they protect it. Decorative concrete stains cannot peel or delaminate since they physically change the appearance of the concrete surface. You would need to grind the surface of the concrete to remove them.

Does vinegar dull marble?

Etching – Vinegar’s ability to dissolve CaCO3 will dull your marble, travertine, concrete and terrazzo surfaces. It may “clean” the surface but it is also dissolving pits into the finish and effectively dulling it. This will affect marble, travertine, concrete and concrete terrazzo surfaces.

What is the best way to etch concrete?

Here, we provide an overview of how to etch concrete (also known as acid washing).

What happens if you don’t etch concrete before an epoxy coating is applied?

If you plan to epoxy your garage floor, for example, it does need to be thoroughly cleaned and free of contaminants, and the pores need to be opened. Acid etching is just one way to do this, but it’s not the only way.

Does etching concrete clean it?

While acid washing/etching does technically clean a surface by removing contaminants, it is really intended to create a surface profile and should not be used as a general-purpose cleaner. It should only be used if you intend to strip the surface, open the pores, and apply a new coating. And even then, it should be used when grinding the surface isn’t possible (see more below).

How to lighten concrete stain?

To lighten the color of stain from a concrete surface. Sometimes when coloring concrete, the release agent sticks a little too hard and the color looks darker than you want it to. If you’re not able to get it off with a normal scrub brush or pressure washer, giving the area an acid wash can do the trick.

What is acid washing?

Acid washing is the process of removing the top layer off a concrete surface to open its pores and provide a clean slate for a coating. Read on to learn about acid washing (also called acid etching) and whether it is the appropriate treatment for your project.

How to make a solution of acid?

Mix acid solution: 1 parts acid to 10 parts water. Always pour acid into water to avoid acid from splashing.

Can you use a grinder to etch concrete?

Another option would be to use a grinder to open the pores of your concrete surface. For DIYers, though, getting ahold of a grinder isn’t an easy task. That’s why some prefer to do an acid wash for concrete etching.

What prevents concrete stain from taking color?

Any materials that inhibit concrete stain penetration, such as grease and oil, or curing membranes, will prevent the color from taking, says Tom Schmidt of Jagger Scored/Stained Concrete, Plano, Texas, a company specializing in decorative staining of residential and commercial concrete floors. Curing membranes, which he encounters more on ...

What materials can prevent concrete from staining?

Any materials that inhibit concrete stain penetration, such as grease, oil, or curing membranes, will prevent the color from taking.

What to use to patch a slab?

If a slab needs patching, use an acrylic-modified, low-shrinkage product that will accept stains. Be aware that these patches will likely show through the finished floor, and the homeowner should be warned in advance.

What is an all purpose concrete cleaner?

All-Purpose Concrete Cleaner Removes sealers and coatings.

Can acid stain concrete floors?

Is chemical stripping dangerous?

Precautions When Using Chemical Strippers. Some chemical strippers can be extremely hazardous to breathe and apply, especially if you're working in an enclosed environment. Be sure to read the Material Safety Data Sheet (MSDS) for the product to check for potential hazards and health effects.

Does Kemiko sell concrete cleaners?

Kemiko, which has been selling acid-based chemical stains for more than 30 years, has an extensive list of concrete cleaning products posted on its web site ( www.kemiko.com) as a handy reference for contractors and do-it-yourselfers.

Why is etching used in concrete?

It is effective in reducing the color variation, creating a more uniform color. Etching can be used to smoothen out a concrete surface. It opens the pores of a concrete slab, enhancing adhesion. Less labor-intensive method than grinding or sandblasting.

What is Acid Etching?

Acid etching is the process of neutralizing a concrete surface through the use of muriatic or phosphoric acid. The acid is applied on the concrete and then rinsed off with water. This has been the standard method for preparing the concrete slab for a coating or overlay. However, the debate on whether it is still acceptable to do is confusing homeowners. Should it be done or not?

Why is concrete coating bad?

Although it is common to blame the coating for being low-quality, it is actually the concrete that failed. Concrete may contain laitance or contaminants that hinder a coating from supposedly sticking on the surface. This is why it is important to prepare the surface well prior to resurfacing.

What to do if you need concrete work done?

If you should have concrete work done in your property, make sure to choose a contractor who uses a safer yet effective surface preparation method. It is important to ask them how they plan to prepare the surface. If they mention acid etching, ask if they could use an alternative method instead.

Is acid etching bad for concrete?

Disadvantages of Acid Etching. Results are inconsistent since not all concretes are the same. It can damage the concrete slab when it is over-etched or under-etched. Since an acid is used, it is dangerous for both humans and the environment.

Is it safe to acid etch concrete?

Safer Alternatives to Acid Etching. There are safer alternatives to acid etching today. Most concrete contractors are no longer recommending acid etching because of its effect on health and the environment.

How to test for acid etching?

Test the mixture in a small space. Most 3:1 or 4:1 mixtures of acid will be a suitable strength for etching concrete. However, before you pour your mixture on to the floor, it's a very wise idea to test it on a small, unimportant area of the concrete (like a spot that would normally be covered by furniture or tool boxes) to make sure it works. Pour about 1/2 cup directly on to the concrete. If it's strong enough, it should immediately begin to bubble and react.

What does it mean when a concrete stain is not reacting?

If there are spots where the acid isn't reacting, this can be a sign that an unnoticed grease stain or sealant was present on the concrete . In this case, you may need to use a mechanical solution, like a grinder, to finish etching the concrete.

How do I seal a concrete driveway?

Apply sealant or epoxy. Many acid etching projects are carried out to prepare a concrete floor for the application of a synthetic epoxy or sealant. These sorts of products give the concrete a professional-looking sheen and also resist water, grease, oil, and other common spills, making the floor easy to maintain. In addition, using an anti-skid additive in your sealant can give your garage or driveway surface the traction your vehicle needs to securely grip it in rain or snow.

What acid is used for etching?

Before you start your etching, you'll want to make sure you have enough of a suitable acid to complete your project — having to run out to the hardware store in the middle of your etching project is a serious pain. Muriatic acid (also called hydrochloric acid) is the most common type of acid used for this project.

How to make acid in a plastic bucket?

1. Mix water and acid in 3 or 4:1 ratio. Add clean, clear water to a plastic bucket. Very carefully pour your acid in, being sure not to cause any spills or splashes. Don't use a metal container — acid can corrode many metals, leading to the possible destruction of the container. Always pour acid into water.

What to do if acid fumes are strong?

If the acid's fumes are strong, use a breathing mask with acid vapor cartridges to prevent injury.

How to stop acid reaction?

Check your acid's label — many will require using a special neutralizing solution to stop the reaction of the acid, while some others may "time out" on their own. For acids that require a neutralizing solution, mix the neutralizer and distribute it throughout the floor according to the instructions on the packaging.

Why is it important to clean concrete?

Because acid stains need to penetrate into the concrete surface to work, it's especially important that the concrete surface is completely clean. DO choose the right cleaning product for the job (see Questions to Ask When Choosing a Concrete Cleaner or Degreaser).

Can you etch muriatic acid?

DON'T etch floors with muriatic acid solutions before staining, in efforts to improve stain penetration. Acid washing depletes the lime content in the concrete, which is what the minerals in the acid stain react with to develop color.

Can you use muriatic acid to etch a floor?

Carpet glue, tile mastics, water and urine stains, chalk marks, caulk, grease stains, paint drips, and rust spots are just a few of the contaminants you may encounter once you remove an existing floor covering. DON'T etch floors with muriatic acid solutions before staining, in efforts to improve stain penetration.

Do you clean concrete before staining?

Cleaning Concrete Before Staining: Important Dos and Don'ts. Unlike paints and coatings for concrete, which are opaque and can disguise many evils, acid stains are transparent. Any unwanted residue remaining on the concrete surface is likely to show through the newly applied stain.

What Is Concrete Etching and Why Should I Do It?

Concrete etching is the process of applying an acid and water solution to a concrete floor in order to roughen the surface of the concrete. The acid wash opens pores in the concrete, which ensures strong adhesion of the new coating to its surface.

What chemicals are used to etch concrete?

Some of these are a blend of chemicals, including muriatic acid and phosphoric acid, and some contain very mild non-toxic acids . These specialized chemicals are a safer alternative to muriatic or hydrochloric acid as they give off fewer fumes, and the eco-friendliness of some products means that they do not require neutralization. However, they can be more expensive and some of them less effective. Let us take a look at the types of acids available for etching concrete.

What is efflorescence in concrete?

Efflorescence is similar to laitance in that it is a build-up of chalk-like substances on newly installed concrete. Instead of containing sand and concrete particles, it contains salts. Efflorescence can provide a similar problem when it comes to the adhesion of a new coating, but etching with muriatic acid can remove this stubborn residue.

How to remove old coating from concrete?

Note: If there is a sealer, curing compound, or an old coating on the concrete, it will have to be removed by sanding or grinding away the surface first, or else the acid will not be effective .

What is hydrochloric acid used for?

Hydrochloric Acid. As well as being found in gastric acid – also known as stomach acid – hydrochloric acid is also used to process steel, treat swimming pools, and is used in the manufacturing of batteries. Hydrochloric acid can also be used in the etching of concrete.

Why does concrete have a lot of water?

It is quite common and is due to too much water in the concrete mix. During the curing process , water rises to the surface and brings with it fine particles of concrete that will eventually dry onto the surface. Thin layers of laitance can be removed by acid etching.

How much water to acid to mix for concrete?

The recommended ratio is four parts water to one part acid. A stronger solution of 3:1 ratio is advised if the concrete is considerably hard or highly polished. If you are unsure, it is best to mix up a small batch of 5:1 acid solution and pour half a cup or so onto an area of the concrete.

What happens if you don’t etch concrete before epoxy?

Acid etching removes laitance, but cannot remove curing compounds or many of the contaminants found in industrial settings, such as oily deposits and water-insoluble materials, any of which can interfere with the adhesion of a coating. Improper surface preparation can result in poor bond and lack of coating adhesion.

How long does concrete need to dry after etching?

After all the water has been removed, the pad should have at least 48 hours of drying time before you apply any etching to the surface. If the weather is particularly humid, wait up to 72 hours for best results.

Is etching concrete necessary?

The short answer is: Yes, even new concrete needs to be etched before applying epoxy or a similar type of garage floor coating. Etching is part of the concrete preparation process. And what many people are not aware, is that proper preparation of the concrete before a coating is applied is the most important part.

Can you seal concrete without etching?

Does vinegar etch concrete?

Does concrete stain easily?

If you’re trying to decide if staining your own concrete is something you can do, make sure you’ve done your homework. Staining concrete is not as easy or as forgiving as staining wood, but that doesn’t mean it is impossible.

Is it better to paint or stain concrete?

Concrete stain embeds the surface to color it translucently, while opaque concrete paint covers the top of the concrete but is subject to chipping and peeling when improperly applied. Concrete stains go on quicker, dry faster and take less work than concrete paint, but they offer no significant protection.