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Historic Preservation - Technical Procedures

Spectitle:
Removing Silicone Caulking Stains From Marble

Procedure code:
0445529R

Source:
Stain Removal Guide For Stone - F. M. Hueston

Division:
Masonry

Section:
Marble

Last Modified:
02/24/2012

Details:
Removing Silicone Caulking Stains From Marble



REMOVING SILICONE CAULKING STAINS FROM MARBLE


THE 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 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on removing silicone
         caulking residue from marble surfaces.  

    B.   Silicone caulking is sometimes used (inappropriately) to
         help hold the anchors in place that secure the stone
         panels.  Often, the silicone will eventually bleed
         through the stone at the location of the anchor holes and
         deposit on the surface, leaving a film that is difficult
         to remove.

    C.   See 01100-07-S for general project guidelines to be
         reviewed along with this procedure.  These 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)

         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).

    D.   For additional information on poulticing, see 04455-02-R.

    E.   For general information on the characteristics, uses and
         problems associated with marble, see 04455-01-S.


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 (*).

    A.   Methylene Chloride:
         
         NOTE:  THIS CHEMICAL IS 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.

         1.   Other chemical or common names include
              Dichloromethane; Methylene bichloride; Methylene
              dichloride.

         2.   Potential Hazards:  TOXIC.

         3.   Available from chemical supply house, dry cleaning
              supply distributor, paint store, photographic
              supply distributor (not camera shop), or printer's
              supply distributor.

    B.   White absorbent material (molding plaster, untreated
         white flour, white tissue, paper towels, powdered chalk,
         talc, fullers earth or laundry whiting)

    C.   Mineral water

    D.   Plastic sheeting

    E.   Clean dry towels for blotting the area after treatment

2.02 EQUIPMENT

    A.   Glass or ceramic container for mixing the solution

    B.   Wooden utensil for stirring the ingredients

    C.   Wood or plastic spatula

    D.   Masking tape


PART 3---EXECUTION

3.01 EXAMINATION

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

3.02 ERECTION, INSTALLATION, APPLICATION

    NOTE:  TEST CLEAN A SMALL AREA BEFORE ATTEMPTING TO CLEAN
    LARGE AREAS.

    A.   Rinse the area to be treated with mineral water.

    B.   Thoroughly moisten the stained surface with the solvent.
         Be sure to dampen well beyond the stain.

    C.   Mix the remaining liquid 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.)

    D.   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.

    E.   Check the coating for air pockets or voids.

    F.   Cover the poultice with plastic sheeting and seal with
         masking tape.

    G.   Let set for 48 hours (unless otherwise specified).

    H.   After set period, dampen the poultice with mineral water.

    I.   Remove the poultice with a wooden or plastic spatula to
         avoid scratching the surface.

    J.   Again, thoroughly rinse the cleaned area with mineral
         water, blot with clean towels and allow the surface to
         dry.

    K.   Once the surface has dried completely, check for
         remaining residue and repeat the treatment if necessary.
         Many applications may be required.

                         END OF SECTION