Answer
May 25, 2021 - 09:28 AM
On the product detail page for this product, under Specs, there are detailed prep instructions.SURFACE OR PRODUCT PREPARATION Always test GBS Penetrating Sealer in a small inconspicuous location first. When in doubt, call us at 888-727-2101. FOUR Surface Requirements BEFORE Applying: 1) Porous 2) Clean 3) Dry 4) Neutral pH I POROUS Porous means it should be able to soak in easily. If there are sealers, paint or adhesives on the surface they will disallow absorption. If the surface has been power-troweled it will make the surface so dense that water will not soak in easily. To test, place a few drops of water onto the surface and see if it beads up or soaks in. If it soaks in and darkens, then the surface is porous and GBS Penetrating Sealer will soak in. If water beads up and does not soak in for about an hour, then there is either something on the surface or it has been power-troweled. If power troweled, use our GBS MicroEtch to open the pores. Do NOT acid etch. Or you can grind with a surface grinder that can be rented from most rental stores. If there is latex paint, adhesives, or other acrylic sealers on the surface we recommend our GBS Industrial Strength Cleaner. If efflorescence (white powder), rust stains, red clay stains appear on the surface, use a non-toxic acidic cleaner.
