Water-Based Sealers for Natural Stone
by Bella Cenzano-Fong, PhD, DuPont Surface Protection Solutions
Every countertop installer, stone fabricator and restoration professional knows the best way to prevent staining on natural stone, masonry and tile is to treat the surface with a protective sealer. The sealer creates a protective barrier that repels spills on the surface, allowing time to wipe them away. Using penetrating sealers is a great way to protect the beauty of the stone, preserve its natural appearance and protect the substantial investment that homeowners make when they invest in natural stone.
But the business of sealers is changing. New environmental regulations, an increased focus on safety and improving technology have many end users turning to water-based sealers instead of solvent-based products containing volatile organic compounds (VOCs). Additionally, by switching to water-based products, many industry professionals believe that they are creating a cleaner, safer environment for their workers and their customers.
A drive to maintain environmental air quality standards has prompted a number of states to restrict the sale of solvent-based stone and tile products in anything greater than a one quart container. These states include Arizona, California, Delaware, Maine, Maryland, New Jersey, New York, Pennsylvania and Virginia. It is highly likely more states will impose similar regulations for similar reasons.
Yet there is good news about alternative sealants for stone professionals. Water-based sealants for stone and tile are excellent alternatives to the traditional solvent-based sealers. They meet all state and federal VOC requirements, reduce harmful fumes and are non-flammable. And, thanks to improving technology, many water-based sealants outperform their solvent-based counterparts.
Water-based products are easy to use and offer significant benefits over solvent-based sealers. They can be applied to any stone or masonry surface where solvent-based sealers would traditionally be used. Water-based sealers can also be applied to damp stone, which speeds up the sealing process. And, from dense, hard granites to wide open limestones, water-based sealers will produce long-lasting and efficient protection against water- or oil-borne stains.
Before choosing a water-based sealant, all stone professionals should know that the sealant selected should be based on the porosity and type of stone or masonry to be sealed. Proper testing of sealers on the actual surfaces to be installed will show which sealer gives the best performance. Testing will also help determine the number of sealer coats required to produce the best performance. Some dense granites may require only one coat while a tumbled limestone paver may need three or more to achieve an efficient seal. Testing also helps determine the method and ease of sealer application.
Applying water-based sealers is slightly different than applying solvent-based sealers. With water-based sealers, working smaller sections, using proper saturation with appropriate dwell times, and efficiently wiping down the surface will produce excellent results. In addition, the tools and equipment used for sealing are important. Proper applicators include brushes, rollers or finish applicators. Applying with sponges and towels, which are designed for picking up liquids, will not give quality results. The proper application requires the surface be well saturated with sealer to give the best protection. Some surfaces can be kept wet for the required dwell time (15 to 30 minutes based on testing), while other thirstier surfaces will need a couple of reapplications during that period. One thing to note: Water-based sealers are a little less forgiving in the wipe-back process than solvents, so accuracy is crucial. Having enough towels on hand to dry the surface easily and quickly is important. A quick wipe with a water-dampened towel can also help ease the clean-up.
Some professionals who have used solvent-based sealers for decades, of course, may be reluctant to switch to water-based products, but they need not worry. Water-based sealants provide excellent quality and outstanding performance with minimal adjustments to their techniques.
At DuPont StoneTech® Professional, we recognize that environmental conditions — and the business of stone care — are constantly changing. That is why, at DuPont, we will continue to focus our scientists on developing new products to address these changing industry needs and allow our customers the freedom to innovate.