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Historic Preservation - Technical Procedures

Spectitle:

Making Job-Prepared Hypochlorite

Procedure code:

0371001S

Source:

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

Division:

Concrete

Section:

Concrete Cleaning

Last Modified:

02/24/2012

Details:

Making Job-Prepared Hypochlorite



MAKING JOB-PREPARED HYPOCHLORITE


PART 1---GENERAL

1.01 SUMMARY

    A.   This standard includes guidance on making job-prepared
         hypochlorite for use in removing specific stains from
         concrete.  It is recommended for use in removal of the
         following stains:

         1.   Beverage Stains:  See 03710-06-R.

         2.   Fire, Smoke, Soot, Pitch and Wood Tar Stains:  See
              03710-19-R.

         3.   Urine Stains:  See 03710-38-R.

         4.   Wood Stains:  See 03710-42-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.   Calcium Hypochlorite (CaCl2O2):

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

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

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

         4.   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.

    B.   Sodium Orthophosphate:

         1.   Other chemical or common names include Tribasic
              sodium phosphate; Trisodium orthophosphate;
              Trisodium phosphate; TSP*; Phosphate of soda*.

         2.   Potential Hazards:  CORROSIVE TO FLESH.

         3.   Available from chemical supply distributor,
              supermarket, grocery, or hardware store.

    C.   Clean, potable water

2.02 EQUIPMENT

    A.   Enameled shallow pan

    B.   Rubber or plastic buckets or stoneware jar


PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

    A.   Dissolve 2 pounds of sodium orthophosphate crystals in 1
         gallon of hot water in a rubber or plastic bucket.

    B.   In a shallow enamel pan, place 12 ounces by weight of
         calcium hypochlorite.  Add water slowly and mix to a
         paste while mashing the lumps.

    C.   Pour the two solutions into another rubber or plastic
         bucket or into a stoneware jar and mix in enough water to
         make a total of 2 gallons of solution.

    D.   Stir well, cover and allow the lime to settle.

    E.   Carefully pour off the liquid for use, leaving the solids
         behind.  The liquid can be siphoned off, but do not start
         the suction by mouth.

                         END OF SECTION