It is important to determine if the project was sealed prior to applying new sealer. Take a small spray bottle of water and simply apply to an area that you suspect has been sealed. If the pavement darkens considerably with the application of water, it most likely was not sealed recently and/or the sealer has worn off.
Determining the type of sealer, solvent or water-based, is critical for application of the new sealer. If there is a residual amount of sealer left on the surface, it will need to be removed using a heated pressure washer surface cleaner and/or a stripping chemical. This will ensure acceptance of new sealer and will not cause a ‘build up’ that will eventually dull the finish. A build up or ‘layers’ caused by over application can also create ‘blushing’. Blushing is when condensation forms between layers of sealer, causing a hazy white appearance.
An easy field test you can perform to determine the type of sealer that was previously applied, is to take a small amount of xylene, toluene or acetone and brush a small amount onto the surface you believe has been sealed. If the brushed on solvent darkens the pavement and appears to have emulsified residual sealer, it is a solvent-based sealer that had been applied. If the brush begins to drag while applying and the solvent turns slightly white, it is a water-based sealer.
GST No-Slip must be applied with a film forming sealer such as Wet Look Low Sheen, Wet Look High Gloss, Satin Seal and Lock’N Seal. It can be mixed into the low pressure pump sprayer and applied evenly. It will be important to keep the spray tip clear.
To ensure even application of No-Slip, continuous agitation while spraying is required.
A clean and dry surface will ensure a deep penetration of the GST sealer achieving maximum longevity of the sealer. If a surface has water and impurities in the capillaries, the solids in the sealer will not be able to displace all of these impurities and the life expectancy of the sealer will decrease substantially. It is necessary to neutralize all acid-based products with GST’s Pro-Grade Cleaner (ph balanced). If the area being cleaned has residual acid-based product that has dried on the surface without being neutralized, it can destabilize the sealer while shortening the life expectancy by up to 50%.
Understanding how to clean a surface by selecting the proper equipment and the proper cleaners will ensure maximum production and performance. Oil remediation, gum removal, soda stains, hard water stains, organic stains, mold/mildew, rust, dust and pollen are just a few of the problems that are dealt with.
Cleaning your hardscape project with a pressure washer and/or a surface cleaner is the first step in preparing for a successful project. It is strongly recommended to utilize a heated pressure washer to aid in the cleaning process. A heated pressure washer in conjunction with Pro-Grade Cleaner will remove most organic stains, weeds, and old polymeric sand in considerably less time than it would take with a cold water unit. A heated pressure washer will also aid in the removal of residual sealer and decrease the labor when ‘stripping’ old sealer off.
Note: For removal of deep seated oil/grease stains, chewing gum residue, and organic stains on all hardscape surfaces, please refer to page 12 for information on GST’s Degreaser Pro.
Efflorescence is a natural by-product from the cement hydration process. Calcium oxide inside the paver reacts with water in the capillaries and forms calcium hydroxide. This migrates to the surface, and reacts with the carbon dioxide in the air to form calcium carbonate, a whitish residue. When moisture on the surface evaporates, the white efflorescence becomes visible.
Efflorescence is usually white in color and is more likely to be visible on darker pavements such as concrete pavers. When calcium oxide combines with carbon dioxide it forms calcium carbonate, which becomes very difficult to remove as it is no longer soluble with water.
Stringent cleaners such as muriatic acid can be very harmful to your pavement, causing irreversible damage to the surface. Most colorants for concrete are made from iron oxide (Fe2O3) or better known as rust. Strong acids like muriatic acid will dissolve these pigments permanently changing the appearance and etching the surface.
GST’s ultimate solution to remove efflorescence from your hardscape project is Clean Concrete. When applied to the affected surface, Clean Concrete will effectively remove the efflorescence. In some cases, where the efflorescence has calcified, multiple applications may be required. Unlike other efflorescence cleaners, our state of the art, environmentally friendly Clean Concrete will limit the negative effects associated with other products.
Once the efflorescence has been removed, it is critical to neutralize the cleaned area with Pro-Grade Cleaner to allow for the proper adhesion of the GST Sealer. When a cleaner or acid is used, it is a common mistake not to neutralize the surface afterwards. Cleaner residue that dries on the surface of your project and is not neutralized, will drastically affect the life expectancy, adhesion performance, and integrity of the sealer applied.
All GST sealers are applied with a sprayer and only 1 coat is necessary to achieve maximum protection and enhancement. GST sealers penetrate deeply filling the capillaries with a one coat application. Additional coats will stay on the surface and the ‘solids’ will build up causing the pavement to become slippery.
You can expect to apply approximately 1500-2000 square feet per hour with a low pressure pump sprayer. Porosity levels will affect the coverage, so be aware of the amount of absorption with the product you are sealing.
If you are applying a solvent-based sealer to an area that was previously sealed, you will need to evaluate the amount of existing sealer that is on surface. The solvent will emulsify the existing sealer and the new sealer will not penetrate into the pavement, potentially causing a slippery surface. Water-based sealers will not mix with solvent-based sealers and vice versa.
An existing solvent-based sealed surface can be revitalized without stripping the existing sealer by lightly spraying a 50% cut version of a GST solvent-based sealer. Acceptable solvents would include acetone, xylene and toluene. This will bring the surface back to its original beauty and luster.