Cleaning Agents or Chemicals PDF Print E-mail

OIL-BASED STAINS
Poultice with baking soda and water OR one of the powdered poultice materials and mineral spirits.

ORGANIC STAINS
Poultice with one of the powdered poultice materials and 12% hydrogen peroxide solution (hair bleaching strength) OR use acetone instead of the hydrogen peroxide.

IRON STAINS
Poultice with diatomaceous earth and a commercially available rust remover. Rust stains are particularly difficult to remove. You may need to call a professional.

COPPER STAINS
Poultice with one of the powdered poultice materials and ammonia. These stains are difficult to remove. You may need to call a professional.

BIOLOGICAL STAINS
Poultice with dilute ammonia OR bleach OR hydrogen peroxide. DO NOT MIX AMMO-NIA AND BLEACH! THIS COMBINATIONCREATES A TOXIC AND LETHAL GAS!

Applying the Poultice

Prepare the poultice. If using powder, mix the cleaning agent or chemical to a thick paste the consistency of peanut butter. If using paper, soak in the chemical and let drain. Don't let the liquid drip.

Wet the stained area with distilled water.

Apply the poultice to the stained area about1/4 to 1/2 inch thick and extend the poultice beyond the stained area by about one inch. Use a wood or plastic scraper to spread the poultice evenly.

Cover the poultice with plastic and tape the edges to seal it.

Allow the poultice to dry thoroughly, usually about 24 to 48 hours. The drying process is what pulls the stain out of the stone and into the poultice material. After about 24 hours, remove the plastic and allow the poultice to dry.

Remove the poultice from the stain. Rinse with distilled water and buff dry with a soft cloth. Use the wood or plastic scraper if necessary.

Repeat the poultice application if the stain is not removed. It may take up to five applications for difficult stains.

If the surface is etched by the chemical, apply polishing powder and buff with burlap or felt buffing pad to restore the surface.