How To Remove Grease and Oil from Natural Stone
The materials in natural stone countertops may vary - marble and granite are common choices. When confronted with an oily stain on a natural stone surface, it may be tempting to use a citrus-based degreaser to try to lift and remove the dark blot. Marble, however, is especially sensitive to acids, and while a citrus/d-limonene solution may seem like the natural choice to counteract grease, it could in fact damage the natural surface of the stone. So instead, there are milder solutions to try.
Before moving on to the most difficult, soaked in stains, it's worth noting that a well-sealed natural stone countertop is likely to be extremely resistant to oil and grease stains. Although natural stone is itself porous, the sealants are often applied after installation and are recommended to be re-applied regularly to help maintain the stain resistance of the surface. For a natural stone surface that is well sealed, soak up and remove the stain with clean dry paper towels. Use a blotting, rather than wiping motion. Apply a small amount of neutral pH soap like Dove to a clean, soft sponge wet with water. Sponge the affected area to remove remaining oil residue. Once the entire area has been cleaned, remove the soap residue with a clean soft sponge, free of soap, wet with water. Use a squeegee to wick away extra moisture and avoid over-wetting and pooling that may damage your countertop and encourage build-up.
For an unsealed surface, or otherwise set-in stain, use a neutral poultice made from cornstarch. Use blotting, rather than wiping motions in the cleaning process to avoid spreading the stain. First soak up and remove any excess oil that has not yet soaked in with clean dry paper towels. Place about 1/4 cup of cornstarch in a shallow dish. Some people may have sensitivity to cornstarch and find it drying or otherwise irritating; Even though it is a common household item and cooking ingredient, protective gear such as gloves and appropriate caution should still be used. Add water to the cornstarch 1 tsp at a time, working into the cornstarch gradually to form a paste. Set aside. Gently press a clean sponge dampened with water to the oil affected area. Apply the cornstarch poultice to the area with plastic spatula or spoon. Cover with plastic wrap and press firmly. Poke holes in the plastic wrap with a toothpick or fork. Allow the poultice to dry, which may take 24 to 48 hours. Once dry, remove and discard the plastic wrap and poultice. If there is still an oily mark remaining, you may have to repeat the process. Once you are satisfied with the oil removal process, apply a small amount of neutral pH soap like Dove to a clean, soft sponge dampened with water. With a more porous natural stone surface, over-wetting should be avoided.Sponge the affected area to remove remaining oil residue. Once the entire area has been cleaned, remove the soap residue with a clean soft sponge, free of soap, wet with water. Use a squeegee to wick away extra moisture and avoid over-wetting and pooling that may damage your countertop and encourage build-up.
Familiarize yourself with the materials in and near the area you wish to clean to avoid damaging the material. Keep clean dry paper towels or soft rags at hand to promptly wipe up stray cleaner that has landed on an incompatible material. Natural stone countertops are best cared for with mild pH neutral products, and may periodically benefit from being re-sealed so that they can continue to resist stains and other substances that may corrode the counter's surface. Stains resistant to removal through normal methods and stains of unknown origin may require the assistance of a professional.
Caution: Never mix cleaning agents or chemicals, the result can be dangerous or deadly. Before cleaning, always test the agent on an inconspicuous location to determine its suitability and to make certain it does not damage the material. Wear appropriate clothing such as gloves and protective eyewear, and work in a well-ventilated area.