Most stones will stain because they are porous. This allows fluids to enter and embed below the surface. The longer a stain remains, the deeper it penetrates and the more permanent it becomes; therefore, it is important to remove a stain as soon as it occurs. This applies to any stone used in the construction of your sink.
Granite is a very durable and resistant stone. For regular cleaning, use a soapy nylon brush in a circular motion and rinse well. Regular cleaning will help prevent the development of hard water deposits. If you develop stubborn stains, try a non-abrasive cleaner such as dish soap, a bleach solution, or Soft Scrub®. Be sure to avoid strong alkalis like ammonia and chemical drain cleaners that involve filling the sink with water. If you find a rust stain, usually caused by iron particles from water, cookware, etc., use a cleaner that contains oxalic acid. Do not use bleach directly on granite!
Marble has a shiny and elegant finish. Maintaining this look can be difficult due to the porosity of the stone. Sealing helps prevent the stone from absorbing liquids, but acidic liquids such as orange juice, lemons, soda, various foods, and common household cleaners will cause a dull etched stain. . For this reason, do not use acidic cleaners on your marble. Wet glasses containing slightly acidic liquids can cause hard water spots. To avoid water spots, rinse and dry your sink after each use. The only way to remove etching and water spots is by professional refinishing and polishing. For regular care, use a mild liquid cleaner with bleach or a common household detergent.
Limestone is known for seashells and the fossils embedded in it. Some limestone is “soft” so care must be taken to scratch or gouge the surface when using sharp objects. Limestone should be treated periodically with a penetrating sealer to protect against staining, especially when working with acidic materials. Possible sealants include Safecoat MexeSeal®, Seal & Go “S”®, and Seal & Go “Enhancer”®.
Soapstone has a silky smooth finish. It is extremely dense so it repels stains well. This stone is the least porous of the stones used in kitchen or bathroom sinks and vessels. To clean, use a damp cloth or sponge with a mild cleaner. Your soapstone sink should be treated monthly with mineral oil.
Stain remover
To remove tough stains on all types of stone, try the following steps before consulting an expert.
1) Clean area with a pH neutral stone cleaner. If this doesn’t help, try a more aggressive cleaner. Be aware of which types of stones are sensitive to certain chemicals, as noted above.
2) Wet its surface with distilled water. This will prevent the chemical from drying too quickly, allowing it to stay in contact with the stain longer.
3) Prepared for poultice. This will be used to absorb the stain from the stone. An easy poultice to make at home requires mixing a cup of flour and a few tablespoons of liquid dish soap. Mix the two together until you have the consistency of peanut butter. You can buy chemical poultices if you prefer.
*For red wine stains, replace the detergent with hydrogen peroxide.
4) Cover the stain with the poultice you’ve created and cover it with saran wrap and tape the edges (it won’t create a permanent residue), then let it sit overnight.
5) After 24 hours, remove the plastic. Let stand uncovered until poultice is dry. This step is important because drying is what removes the stain from the stone. You can then scrape off the poultice with a razor blade or spatula. Clean residue with water and a neutral cleaner.
*Granite is more porous than other stones, so it will retain moisture for longer. If the stain seems to have disappeared, but the stone is slightly darker in color, let it dry for a week or more before trying the poultice method again.
For more information on stone sinks, whether for the kitchen, bathroom, or bar, visit Sinks Gallery, where you’ll find the largest variety of artisan and handcrafted sinks available anywhere. There are several more articles online in the “tips” section.