Removing Adhesives from Marble

PART 1–GENERAL

1. 01 SUMMARY
   1. This specification provides guidance on removing the sticky adhesive residue left behind after removing signage or other objects which have been applied directly to the marble surface.
   2. Surface-mounted signage is a common problem in GSA buildings, both on the exterior and in public lobbies. The signage is often applied directly to the stone surface with an adhesive. This solution for needed signage is unsightly, and reversal is often difficult, leaving the surface discolored and stained. Free- standing signage is usually the preferred solution, when possible.
   3. Read “General Project Guidelines” along with this specification. These guidelines should be reviewed prior to performing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO). The guidelines cover the following sections
      1. Safety Precautions
      2. Historic Structures Precautions
      3. Submittals
      4. Quality Assurance
      5. Delivery, Storage and Handling
      6. Project/Site Conditions
      7. Sequencing and Scheduling
      8. General Protection (Surface and Surrounding)
   4. See also:
      1. “Removing Unknown Stains from Marble Using a Poultice”
      2. “Marble: Characteristics, Uses and Problems”

1. 02 CAUTION

1. Projects involving use of hazardous chemicals are subject to employee safety and environmental laws governing use and disposal of volatile organic compounds (VOCs). Specified products may not be permitted or appropriate for all locations. Products containing chemicals known to present health or environmental hazards should be used only as a last resort, where permissible, in accordance with manufacturer’s directions and government requirements. Test milder formulations for effectiveness before proceeding to stronger alternatives.
2. Cleaning or removal of stains from stone may involve the use of liquids, detergents or solvents which may run off on adjacent material, discolor the stone or drive the stains deeper into porous stones. Use the products and techniques described here only for the combinations of dirt/stain and stone specified.

PART 2–PRODUCTS

2.01 MATERIALS

NOTE: Chemical products are sometimes sold under a common name. This usually means that the substance is not as pure as the same chemical sold under its chemical name. The grade of purity of common name substances, however, is usually adequate for stain removal work, and these products should be purchased when available, as they tend to be less expensive. Common names are indicated below by an asterisk (*).

1. Acetone (C3H6O):
   1. A volatile fragrant flammable liquid ketone used chiefly as a solvent and in organic synthesis.
   2. Other chemical or common names include Dimethyl ketone; Propanone
   3. Potential Hazards: VOLATILE AND FLAMMABLE SOLVENT
   4. Available from chemical supply house or hardware store.
2. Mineral Spirits:

1. A petroleum distillate that is used especially as a paint or varnish thinner.
2. Other chemical or common names include Benzine* (not Benzene); Naphtha*; Petroleum spirits*; Solvent naphtha*.
3. Potential Hazards: TOXIC AND FLAMMABLE.
4. Safety Precautions:
   1. AVOID REPEATED OR PROLONGED SKIN CONTACT.
   2. ALWAYS wear rubber gloves when handling mineral spirits.
   3. If any chemical is splashed onto the skin, wash immediately with soap and water.
5. Available from construction specialties distributor, hardware store, paint store, or printer’s supply distributor.

3. Toluene:(C7H8):
   1. A liquid, aromatic hydrocarbon that resembles benzene but is less volatile, flammable and toxic; Is produced commercially from light oils from coke- oven gas and coal tar and from petroleum, and is used as a solvent, in organic synthesis and an antiknock agent for gasoline.
   2. Other chemical or common names include Toluol.
   3. Potential hazards: TOXIC AND FLAMMABLE.
   4. Available from chemical supply house, hardware store, paint store or printer’s supply distributor.
4. Xylene:(C8H10):
   1. Any of three toxic, flammable, oily, isomeric, aromatic hydrocarbons that are di-methyl homologues of benzene and are obtained from wood tar, coal tar, or petroleum distillates; Also a mixture of xylenes and ethyl-benzene used chiefly as a solvent.
   2. Other chemical or common names include Xylol; P- xylene; 1,4-dimethyl benzene.
   3. Potential Hazards: TOXIC AND FLAMMABLE.
   4. Available from chemical supply house, hardware store, paint store or printer’s supply distributor.
5. Methylene Chloride:

1. NOTE: Methylene chloride, a known carcinogen banned in some states such as California. Regulatory information as well as alternative or equivalent chemicals may be requested from the Environmental Protection Agency (EPA) Regional Office and/or the State Office of Environmental Quality. Consult manufacturers regarding potential substitutes for the particular application and conditions. Potential substitute products include: Commercial cleaner such as “ASPIR Solv Safe Solvent Cleaner” (Diedrich Technologies, Inc.), “Sure Klean Asphalt & Tar Remover” (ProSoCo, Inc.), “Sure Klean Fast Acting Stripper” (ProSoCo, Inc.), “Sure Klean Heavy Duty Paint Stripper” (unpolished marble only ProSoCo, Inc.) or approved equal.
2. Other chemical or common names include Dichloromethane; Methylene bichloride; Methylene dichloride.
3. Potential Hazards: TOXIC.
4. Available from chemical supply house, dry cleaning supply distributor, paint store, photographic supply distributor (not camera shop), or printer’s supply distributor.

6. White absorbent material (molding plaster, untreated white flour, white tissue, paper towels, powdered chalk, talc, Fullers earth or laundry whiting).
7. Mineral water.
8. Plastic sheeting.
9. Clean dry towels for blotting the area after treatment.

2.02 EQUIPMENT

1. Razor blade.
2. Glass or ceramic container for mixing the solution.
3. Wooden utensil for stirring the ingredients.
4. Wood or plastic spatula.
5. Masking tape.

PART 3–EXECUTION

3.01 EXAMINATION

Examine the marble surface CAREFULLY to determine the cause of staining before proceeding with any cleaning operation.

3.02 ERECTION, INSTALLATION, APPLICATION

1. Carefully remove any sticky residue using a sharp razor blade.
2. Wipe remaining residue with a clean, soft rag saturated with acetone. Continue to wipe the area until all of the residue has been removed.
3. If the surface is stained or discolored, prepare and apply a poultice:
   1. NOTE: Test the different solvents to see which is the most effective on the stain. ALWAYS TEST A SMALL AREA FIRST, AND OBTAIN APPROVAL FROM RHPO BEFORE PROCEEDING WITH THE TREATMENT OF LARGER AREAS.
   2. Rinse the area to be treated with mineral water.
   3. Thoroughly moisten the stained surface with the solvent. Be sure to dampen well beyond the stain.
4. Mix one of the solvents (Mineral spirits, Toluene, Xylene or Methylene chloride) with the white absorbent material to form a paste the consistency of oatmeal or cake icing. (Approximately one pound of paste is needed for every square foot of surface area to be treated.)
5. Using a wooden or plastic spatula, apply the paste to the stained surface in layers no more than 1/4 inch thick. The poultice should extend well beyond the stain to prevent forcing the stain into previously clean stone.
6. Check the coating for air pockets or voids.
7. Cover the poultice with plastic sheeting and seal with masking tape.
8. Let set for 48 hours (unless otherwise specified).
9. After set period, dampen the poultice with mineral water.
10. Remove the poultice with a wooden or plastic spatula to avoid scratching the surface.
11. Again, thoroughly rinse the cleaned area with mineral water, blot with clean towels and allow the surface to dry.
12. Once the surface has dried completely, check for remaining stains and repeat the treatment if necessary.