This page will help you understand how to seal your acid stained concrete.
The methods and sealers I'm going to show you will also work good for acetone dye stained concrete and water based concrete stains.
Some of the reasons you need to seal stained concrete are:
Most concrete sealers used on acid stained concrete are either solvent or water based acrylics.
There are others like epoxies, urethanes, and polyaspartics, but for the most part, acrylic-based sealers are used to seal acid stained concrete.
Acrylic based concrete sealers are the easiest to apply and usually less expensive than the other sealers on the market.
My favorite sealer is Foundation Armor's AR 350 solvent based sealer.
The important things for you to know are how to apply this sealer to acid stained concrete and what to expect from it after you or your contractor apply it.
FOR INTERIOR STAINED CONCRETE FLOORS:
A water-based acrylic concrete sealer works best. The sealer should have 20 - 25 % solids, this will allow it to breath, allow for easier application, and give you the color enhancement most people desire.
My recommendation for sealer is Foundation Armor WL550 Sealer.
The main reason for using a water based sealer for interior floors is it doesn't have the fumes and smell that a solvent based sealer will have.
If you're already living in the structure or it's a place of business where people are working, I would go with the water based sealer.
There's hardly any fumes or smell from this sealer when you apply it and as it's drying.
FOR EXTERIOR AND SOME INTERIOR STAINED CONCRETE:
My preference is to use a solvent based acrylic sealer on all my stained concrete jobs.
The only time I don't is when people are living in the home or the building is in use at the time of sealing.
Solvent based sealers do have fumes when you apply it. The fumes usually last for a couple days as the sealer dries. The first few hours are the worst. Ventilation is key, applying outside is no problem.
I like the solvent sealer because I think it enhances the colors a little better than a water based sealer does.
I also like the way it sprays out on the surface and dries quicker than a water based sealer.
Like I said above, my recommendation for a solvent based sealer is Foundation Armor's AR 350. This sealer will darken and enhance the color and leave you with a matte finish.
If you like the high gloss look, I recommend Foundation Armor's AR500.
PREP YOUR CONCRETE BEFORE YOU SEAL:
The concrete surface preparation is very important. The surface of the concrete should have been neutralized after acid staining with a solution of 1/2 pound baking soda mixed with 5 gallons of water.
After mopping (or spraying) this solution on the concrete and rinsing & vacuuming it off, the surface should have been rinsed at least another 2 times or until the rinse water is clean with no color.
After rinsing, you should let the surface dry a minimum of 24 hrs and 48 hrs. in damp, humid conditions.
Sealing your concrete without letting it completely dry out will cause problems with the sealer.
After cleaning the concrete and letting it completely dry, you're ready to apply your concrete sealer.
There are a few ways you can apply the sealer to the concrete. You can roll it on with a 3/8 inch nap lint free roller, you can spray it on with a pump up sprayer (you may need to back-roll with a paint roller for an even coverage), or you can use a lambs wool applicator for smooth surfaces.
Two people make this process really easy. I spray on a very light coating of the sealer and my helper immediately rolls the sealer to ensure an even coating.
I only spray an area as wide as the handle on the paint roller so the person back rolling can reach without stepping into the sealer.
This method of spraying and back rolling really lays out the sealer nice and even as well as forcing the sealer down into the pores of the concrete for better adhesion.
If you do spray your sealer, be careful to mask off anything you don't want to get sealer on. You will have some over-spray around the edges.
This training video will show you how I apply sealer to colored and stained concrete using the spray and back roll method.
It will also show you how I clean and re-seal concrete after it's a year or two old and starts showing signs of wear.
The concrete sealer should be mixed with a battery drill and mixing paddle prior to pouring it in a painter's tray or a pump up sprayer.
I also like to pour the concrete sealer through a piece of screen to catch any small lumps or debris before pouring it into a sprayer.
The tips on pump-up sprayers clog very easily so screening is a must, even a coffee filter will work.
Acrylic concrete sealers for decorative acid stained concrete need to go down very thin.
1 to 2 mils thick is enough for each coating. That's about 350 to 450 square feet per gallon.
I usually apply at least 2 coats and a lot of times I'll do 3. Depending on the temperature the sealer usually dries fairly quickly 1 to 2 hours at about 70 degrees F.
I apply the 2nd coating when the first is tack free and I can walk on it without my shoes sticking to the surface.
The sealer must remain breathable, if you apply it too thick the sealer could turn white, foggy, or blisters and bubbles could form.
The best time of day and the best temperatures to apply your sealer are late afternoon with the temperature between 55 - 80 degrees F.
On interior applications where you have a controlled temperature, any time is good.
If the temperature is too cold or too hot the sealer will dry too slow or too fast which increases the chances of it not curing properly.
Avoid early mornings on exterior stained concrete as there could be moisture on the concrete.
Also remember, moisture is your enemy when your sealing concrete, if you see moisture on the surface of the concrete or if there is a chance of rain in the next 24 hours, delay applying the sealer until those issues are resolved and the concrete is very dry.
1. Understand the concrete sealer is just a sacrificial coating to help enhance and protect the concrete. You will have to maintain the concrete sealer, applying a new coat as it shows wear.
2. Apply the sealer coatings very thin, most sealer failures are from applying the concrete sealer too thick.
3. Use 20% -25% solids acrylic sealers, they breath better, enhance the color, and are easier to apply.
4. Choose a satin or matte finish, high gloss concrete sealers show scratches and imperfections much more than low gloss sealers.
5. For exterior applications the sealer will make the concrete slippery, you may want to add a non-slip additive.
6. For interior applications apply an acrylic wax over the concrete sealer. The wax will be the wear surface allowing you to maintain the wax instead of the sealer (much easier in my opinion).
7. Acrylic concrete sealers are not very good when it comes to chemical and stain resistance, be careful what you spill and wipe it up in a timely fashion.
This method I use for applying concrete sealer to acid stained concrete is what I've been doing on my stain jobs for many years.
The acrylic sealer, spraying & back-rolling is what I use on acetone dye stain floors, water-based stained floors, and colored stamped concrete.
I like Foundation Armor's acrylic sealers for these types of applications. Foundation Armor stands behind their sealers, they have really good customer support and most important, they have a good high quality concrete sealer.