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Historic Preservation - Technical Procedures

Spectitle:

Poulticing Plywood Or Joint Sealant Stains From Concrete

Procedure code:

0371034R

Source:

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

Division:

Concrete

Section:

Concrete Cleaning

Last Modified:

02/24/2012

Details:

Poulticing Plywood Or Joint Sealant Stains From Concrete



POULTICING PLYWOOD OR JOINT SEALANT 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 poulticing pink
         stains from concrete produced by plywood or joint
         sealants.

    B.   The alkalies in concrete may react with phenol-formaldehyde
           resins in plywood or with the phenolics used in some
           joint sealants to form pink staining compounds.

    C.   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 additional 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 (*).

    NOTE:  THESE SOLUTIONS BLEACH COLORED CLOTHING AND CAN BE
    CORROSIVE TO METALS.

    A.   Sodium Hypochlorite (NaOCl):

         1.   An unstable salt produced usually in aqueous
              solution and used as a bleaching and disinfecting
              agent.

         2.   Other chemical or common names include Bleaching
              solution*; Household bleach*; Laundry bleach*;
              Solution of chlorinated soda*.

         3.   Potential Hazards:  CORROSIVE TO FLESH.

         4.   Available from chemical supply house, grocery store
              or supermarket, hardware store or janitorial supply
              distributor.

         -OR-

         Potassium Hypochlorite:  

         1.   Potential Hazards:  CORROSIVE TO FLESH.

         2.   Available from chemical supply house or hardware
              store.

         -OR-

         Javelle Water:  Made by user, see 03710-02-S for guidance
         on preparation.

         1.   Calcium Hypochlorite (CaCl2O2):

              a.   A white powder used especially as a bleaching
                   agent and disinfectant.


              b.   Other chemical or common names include
                   Chlorinated calcium oxide; Bleaching powder*;
                   Calcium oxymuriate*; Chloride of lime*;
                   Chlorinated lime*; Hypochlorite of lime*;
                   Oxymuriate of lime*.

              c.   Potential Hazards:  CORROSIVE TO FLESH;
                   FLAMMABLE (WHEN IN CONTACT WITH ORGANIC
                   SOLVENTS).

              d.   Available from chemical supply house, dry
                   cleaning supply distributor, drugstore or
                   pharmaceutical supply distributor, janitorial
                   supply distributor, swimming pool supply
                   distributor, or water and sanitation supply
                   distributor.

         2.   Sodium Carbonate (Na2CO3):

              a.   A sodium salt of carbonic acid used especially
                   in making soaps and chemicals, in water
                   softening, in cleaning and bleaching and in
                   photography; A hygroscopic crystalline
                   anhydrous strongly alkaline salt.

              b.   Other chemical or common names include
                   Carbonate of soda*; Sal soda*; Soda*; Soda
                   ash*; Washing soda*.

              c.   Available from chemical supply house, grocery
                   store or supermarket, hardware store, paint
                   store, or water and sanitation supply
                   distributor.

    B.   Filler material such as diatomaceous earth or talc

    C.   Mineral water

    D.   Clean dry towels for blotting the area after treatment

    E.   Scouring powder

    F.   Clean, potable water

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

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.   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.   Mix 1 part hypochlorite solution (diluted with 4 to 6
         parts water) with enough talc to make a thick paste.  


         1.   Select the amount of talc to make a poultice of the
              required size.  Add hypochlorite solution to obtain
              the proper paste-like consistency.

         2.   The undiluted hypochlorite solution can be
              commercial household bleach (which is about 5%
              sodium hypochlorite) or 5% potassium hypochlorite
              solution or Javelle water.  For guidance on making
              javelle water, see 03710-02-S.

    B.   Thoroughly wet the concrete surface to be treated with
         clean, clear water.

    C.   Apply the poultice mixture to the stained area using a
         wood or plastic spatula and allow to dry.  Be sure to
         spread the poultice well beyond the stained area.  The
         liquid portion of the paste will migrate 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