Let's continue our discussion about how to choose concrete sealers for your countertops. Generally, the best sealer we have found that is a happy medium between cost, appearance, and protection is either a water or solvent based polyurethane. However, we have other sealer types available depending on what our clients want. This particular project was done at a "Chuy's" Mexican restaurant in Fort Worth, TX. We first poured a bar countertop and then sealed it with a clear epoxy.
These countertops are in a very tough environment. They have everything from spilled beer to searing hot fajita plates on them, so we used the toughest concrete sealer there is to protect them—a polyurea (epoxy based) sealer. Epoxy sealers will deepen the color of the countertop and usually leave it with a high gloss finish. They are very tough, but they're the hardest to touchup of all the sealer options. They normally have two components, a part A and part B, that are mixed together in a specific ratio and through a chemical reaction begin to harden. The trick is to get it all down, smoothed out, and looking good before it hardens too much. Epoxy sealers also have "build," i.e., they go down much thicker than other types of sealers. It's this thickness that gives them so much "pop." We often do these in restaurants since they want that deep, spilled water look for their countertops.
One small step down from epoxy in our search for the best concrete sealers for concrete countertops are polyurethane sealers. These are very durable and are resistant to virtually all food stains due to being completely impermeable, a characteristic they share with epoxy sealers. By impermeable we mean that a liquid will not penetrate through the sealer no matter how long the liquid sits on it. This of course is dependent on the type of liquid; industrial solvents can sometimes soften and penetrate the sealer, but you normally don't have those in a kitchen or bathroom, and it depends on whether ot not the sealer has been compromised—no cutting on it!
Polyurethane sealers come in two types, water or solvent based. The solvent based deepen the color of the countertop surface and leave it with a very high gloss finish. Water based polyurethanes have a more matte, natural-looking finish, and generally only slightly darken the color of the concrete. Polyurethane is easier and less expensive to apply than epoxy sealers and simpler to touchup if there's any damage. They are actually more scratch resistant than epoxies, but like epoxy sealers, placing very hot pans or cutting directly on them can damage the finish. Overall, they are an excellent choice for the average home concrete countertop.
The most economical option of concrete sealers for concrete countertops is an acrylic sealer. These type of sealers are very easy to apply and touchup if they are damaged, with the tradeoff being that they are softer and less stain resistant than the polyurethane or epoxy sealers. In fact, acrylic sealers, whether solvent or water based, are semi permeable, i.e., they "breathe." What this means is that if something spills on them, it won't get through to the concrete immediately, but eventually the liquid will penetrate through the sealer and can etch or stain the concrete underneath. While we've applied acrylic sealers to many countertops, we always advise our clients that they have to be vigilant about spills, or some staining can occur.