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Historic Preservation - Technical Procedures

Spectitle:

Pouticing Candy And Confectionery Stains From Concrete

Procedure code:

0371008R

Source:

Hstrc Concrete: Investigation & Rpr/Pre-Conf Training - 1989

Division:

Concrete

Section:

Concrete Cleaning

Last Modified:

02/24/2012

Details:

Pouticing Candy And Confectionery Stains From Concrete



POULTICING CANDY AND CONFECTIONERY STAINS FROM CONCRETE


THE CLEANING OR REMOVAL OF STAINS FROM CONCRETE MAY INVOLVE THE
USE OF LIQUIDS, DETERGENTS OR SOLVENTS WHICH MAY RUN OFF ON
ADJACENT MATERIAL, DISCOLOR THE CONCRETE OR DRIVE THE STAINS DEEPER
INTO POROUS CONCRETE.  USE THE PRODUCTS AND TECHNIQUES DESCRIBED
HERE ONLY FOR THE COMBINATIONS OF DIRT/STAIN AND CONCRETE SPECIFIED.


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on removing candy stains
         from concrete by scrubbing with a detergent or by
         poulticing with a solvent.

    B.   Safety Precautions:

         1.   DO NOT save unused portions of stain-removal
              materials.

         2.   DO NOT store any chemicals in unmarked containers.

         3.   EXCELLENT VENTILATION MUST BE PROVIDED WHEREVER ANY
              SOLVENT IS USED.  USE RESPIRATORS WITH SOLVENT
              FILTERS.

         4.   No use of organic solvents indoors should be
              allowed without substantial air movement.  Use only
              spark-proof fans near operations involving
              flammable liquids.

         5.   Provide adequate clothing and protective gear where
              the chemicals are indicated to be dangerous.

         6.   Have available antidote and accident treatment
              chemicals where noted.

    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 general information on poulticing, see 04455-02-R.


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.   Detergent

    B.   For Stains Containing Chocolate:

         1.   Ammonium Hydroxide (NH5O):

              a.   A weakly basic compound that is formed when
                   ammonia dissolves in water and that exists
                   only in solution.

              b.   Other chemical or common names include Ammonia
                   water*; Aqua ammonia*; Household ammonia*.

              c.   Potential hazards:  TOXIC; MAY IRRITATE THE
                   EYES.

              d.   Available from chemical supply house, grocery
                   store or pharmaceutical supply distributor, or
                   hardware store.

         2.   Denatured Alcohol:

              a.   Other chemical or common names include
                   Methylated spirit*.

              b.   Potential hazards:  TOXIC AND FLAMMABLE.

              c.   Available from hardware store, paint store or
                   printer's supply distributor.

              d.   Denatured alcohol, which carries no liquor
                   tax, should be a satisfactory substitute for
                   ethyl alcohol for stain removing purposes.

    C.   For Stains Resulting from Artificial Food Coloring:

         1.   One of the following solvents:

              Carbon Disulfide (CS2):

              a.   A colorless flammable poisonous liquid used as
                   a solvent for rubber and as an insect
                   fumigant.

              b.   Other chemical or common names include Carbon
                   bisulfide*; Carbon sulfide*.

              c.   Potential Hazards:  TOXIC AND FLAMMABLE.

              d.   Available from chemical supply house,
                   drugstore or pharmaceutical supply
                   distributor, garden and lawn supply center,
                   hardware store, or paint store.

              -OR-

              Carbon Tetrachloride (CCl4):

              a.   A colorless, nonflammable, toxic liquid that
                   has an odor resembling chloroform and is used
                   as a solvent (as in dry cleaning) and a fire
                   extinguisher.

              b.   Other chemical or common names include
                   Perchloromethane; Tetrachloromethane.

              c.   Potential Hazards:  TOXIC.

              d.   Available from chemical supply house, dry
                   cleaning distributor, hardware store, paint
                   store or photographic supply distributor (not
                   camera shop).

              -OR-

              Chloroform (CHCl3):

              a.   A colorless volatile heavy toxic liquid with
                   an ether odor used especially as a solvent or
                   as a general anesthetic.

              b.   Other chemical or common names include
                   Methylene trichloride; Trichloromethane.

              c.   Potential Hazards:  TOXIC.

              d.   Available from chemical supply house, dry
                   cleaning supply distributor, drugstore or
                   pharmaceutical supply distributor, or paint
                   store.

         2.   Filler material such as diatomaceous earth or talc

         3.   Mineral water

         4.   Clean dry towels for blotting the area after
              treatment

    D.   Accessible source of clean water, soap and towels for
         washing and rinsing in case of emergencies associated
         with the use of chemicals

    E.   Stiff bristle brushes (non-metallic)

2.02 EQUIPMENT

    A.   For Poulticing:

         1.   Glass or ceramic container for mixing the solution

         2.   Wooden utensil for stirring the ingredients

    B.   Wood or plastic spatula

    C.   Stiff bristle brush (non-metallic)


PART 3---EXECUTION

3.01 PREPARATION

    A.   Protection:

         1.   Provide adequate wash solutions (i.e. water, soap
              and towels) before starting the job.

         2.   Whenever acid is used, the surface should be
              thoroughly rinsed with water as soon as its action
              has been adequate.  Otherwise it will continue
              etching the concrete even though the stain is gone.

3.02 ERECTION, INSTALLATION, APPLICATION

    NOTE:  DO NOT TRY MORE THAN ONE TREATMENT ON A GIVEN AREA
    UNLESS THE CHEMICALS USED FROM PRIOR TREATMENT HAVE BEEN
    WASHED AWAY.

    A.   Thoroughly saturate the surface with clean, clear water.

    B.   Using a stiff (non-metallic) bristle brush, try scrubbing
         the stained area with a detergent mixed with water.

    C.   Thoroughly rinse the surface with clean, clear water and
         allow to dry.

    -OR-

    D.   If this does not sufficiently remove the stain, try one
         of the following:

         1.   For stains containing chocolate, scrub the surface
              with ammoniacal alcohol:

              a.   Mix 1 part ammonium hydroxide solution
                   (containing 26% ammonia) with 9 parts
                   denatured alcohol.

              b.   Thoroughly saturate the concrete with clean,
                   clear water.

              c.   Using a stiff bristle brush, scrub the
                   solution over the stain.

              d.   Thoroughly rinse the surface with clean, clear
                   water and allow to dry.

              e.   Repeat the process as necessary to achieve the
                   desired level of cleanliness.

         -OR-

         2.   If the stain is badly colored due to artificial
              food colorings, try poulticing with carbon
              disulfide, carbon tetrachloride or chloroform.

              a.   Mix filler material and solvent to create a
                   thick paste.  Select the amount of filler to
                   make a poultice of the required size.  Add
                   solvent to obtain the proper paste-like
                   consistency.

              b.   Thoroughly saturate the concrete with clean,
                   clear water.

              c.   Apply the poultice to the stained area using a
                   wood or plastic spatula.  Be sure to spread
                   the poultice well beyond the stained area.
                   The liquid portion of the paste will migrates
                   into the concrete where it will dissolve some
                   of the staining material.  Then the liquid
                   will gradually move back beyond the concrete
                   surface and into the poultice, where it will
                   evaporate, leaving the dissolved staining
                   material in the poultice.

              d.   When the poultice has dried, brush or scrape
                   it off with a wooden scraper.  

              e.   Using a stiff bristle brush, scrub the surface
                   with scouring powder and clean water to remove
                   any residual staining.

              f.   Thoroughly rinse the area with clean, clear
                   water and allow to dry.

              g.   Repeat the process as necessary to achieve the
                   desired level of cleanliness.

                         END OF SECTION