The answer depends on the surface's square footage. For large surfaces such as commercial floors, a sprayer is faster and way more efficient. Finally, for small surfaces, such as garages or any other exterior surface, a paint roller or any other type of roller will do the trick. Rolling is a less expensive process.
Do not pour the sealer directly onto the concrete. Use a paint pan. Apply the sealer with a paint roller in 2 very thin and even coats.
Rollers are used for lower-viscosity concrete sealers while push-pull applicators are used for higher-viscosity sealers or coatings. The roller marks or lap lines can show up with any sealer or coating and on any surface or substrate.
A light touch, slow and easy on the roller or applicator, and not overworking the sealer or coating should lead to lap-line- and roller-mark-free sealed floors.
Airless and HVLP Sprayers
Airless and HPLV (High Velocity Low Pressure) sprayers make great options if you're looking for a great way to apply your sealer coating. They generally offer a variety of adjustable tips so you can get the job done – no matter what your need.
(1) Once you've finished spraying, empty any sealer left in the sprayer. Don't wait. We recommend that you not allow sealer to sit in your sprayer for more than 10-15 minutes.
A hand pump sprayer is ideal for water-based sealers and for small surface areas. A low-pressure high-volume sprayer, such as the Chapin Acid Staining Sprayer, can be used with any sealer type, and it creates professional-looking finishes. Rollers can also be used to apply sealer, but a sprayer will do a better job.
Another mistake to avoid is applying the sealer too thickly. Concrete sealer is supposed to dry quickly, but it won't if you put too much on, and this compromises its long-term effectiveness. It's better to apply it too thin and apply a second coat later.
But if the sealer isn't applied uniformly to begin with, or if not enough coats are used, the slab will appear blotchy upon drying. This is caused by the sealer filling in some of the valleys, but not all, and failing to remain on top of the hills.
Roller: A paint-type roller with a 1/4- to 3/8-inch nap can be used to apply both water- and solvent-based sealers.
Concrete sealers are best applied in two thin coats. The first coat of sealer acts like a primer. Most of it will disappear into the concrete surface, and the concrete will probably look fairly unattractive after the first coat. The second thin coat will provide an even finish, color enhancement and gloss.
Pour the QUIKRETE® Concrete Sealer slowly into a clean container. Stir gently but thoroughly to mix. Rigorous stirring can form air bubbles in the sealer, which could affect the final finish.
Apply the first coat, waiting at least two hours before applying the second. Check your sealant can for specific drying times. Apply two thin coats to ensure a smooth and even finish.
While it is always best to follow a manufacturer's suggestions for when and how to apply a concrete sealer, we have found the best time to apply most concrete sealers is in the late afternoon or early evening.
“You want it very clean, but it must also be very dry,” he says. “You don't want to seal wet concrete.” Applying sealer to wet concrete will cause problems, adds Sacco, as the sealer can fog up. Sacco also suggests that once the concrete is completely dry, avoid applying the sealer during the heat of the day.
In order to properly seal your concrete, then, you must clean the surface of the substrate before applying a concrete sealer of any variety. The easiest and most effective way to clean the concrete will vary depending on the condition of your concrete and whether it has been treated with chemical stains.
It is best to apply two or even three thin coats, allowing each coat to dry between applications. This will prevent puddling that can create uneven coverage. Overlap the areas as you apply the sealer to ensure full coverage.
Coating problems can include surface bubbles (aka solvent pop), peeling/flaking, white spots (aka blushing), fading (loss of shine). Surface bubbles (aka solvent pop) can occur during the coating application process when solvent is evaporating too quickly from a sealer.
If you experience any dew, accidental sprinkling of water or rain as the sealant dries, the sealant can become stained, cloudy, blotchy, or discolored and it will no longer be aesthetically pleasing. Simply don't seal your paver if there is even a remote chance of rain, fog, or a drizzle.
A strong enough power washer will blast most types of sealer off of concrete with ease. The trick is to make sure to pressure wash the entire surface area. For more sturdy sealers, it may take a few passes with the pressure washer to get it completely removed.
Once applied, sealers create a chemical reaction and the outside temperature decides how fast that reaction occurs—or if it happens at all. Most manufacturers recommend 50 to 90 degrees as the ideal temperature range for applying concrete sealer.
At a typical coverage rate of 300 square feet per gallon, one coat of an acrylic concrete sealer should be about 5 mils thick when wet. When dry, the sealer is only about 2 mils thick. (For comparison, a sheet of copy paper is about 10 mils thick and a credit card is 120 mils thick.)
If water evaporates too quickly, it will weaken the finished product with stresses and cracking. To put it simply, the goal is to keep the concrete saturated during the first 28 days. The first 7 days after installation you should spray the slab with water 5-10 times per day, or as often as possible.
DO spray new concrete with water. One of the most common methods for curing concrete is to hose it down frequently with water—five to 10 times per day, or as often as you can—for the first seven days. Known as “moist curing,” this allows the moisture in the concrete to evaporate slowly.