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Historic Preservation - Technical Procedures

Spectitle:

Water Washing Of Metal With/Without Detergents

Procedure code:

0572501P

Source:

Outdoor Sculpture Manual - Center For Public Buildings

Division:

Metals

Section:

Ornamental Metal Castings

Last Modified:

02/24/2012

Details:

Water Washing Of Metal With/Without Detergents



WATER WASHING OF METAL WITH/WITHOUT DETERGENTS


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on cleaning metal by
         mild water washing with or without detergents and soft
         natural bristle brushes.


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   GAF Corporation
         1361 Alps Road
         Wayne, NJ  07470
         201/628-4127

2.02 MATERIALS

    A.   Non-ionic detergent, such as "Zyfo" cleaner concentrate
         -a controlled suds, silicate buffered, non-ionic,
         rinseless-type synthetic detergent, containing no soap,
         free alkali, solvents, abrasives, acids, caustics or the
         like, "Igepal 630" (GAF Corporation) or approved equal.

    B.   Supplementary Materials for Bronze:

         1.   Bronze wool, extra fine, such as that manufactured
              by Brillo

         2.   Corrosion Inhibitor, Benzotriazole (BTA) such as
              "Cobratec" (GAF Corporation), or approved equal

    C.   Supplementary Materials for Cast Iron:

         1.   600 grit aluminum oxide paper, emery paper or fine
              steel wool

         2.   Complexing agent such as "Versene", or approved
              equal

    D.   Clean, potable water

    E.   Toweling or rags, clean, lint-free

2.03 EQUIPMENT

    A.   Buckets, molded rubber or plastic, such as the "Fortex"
         molded rubber pail - 12 or 14 quart size, or Rubbermaid

    B.   Washing brushes:  Available from local janitorial supply
         houses or hardware stores

         1.   Tampico fiber set in a hardwood block

         2.   "Whitewash brush" - ideal for most purposes

         3.   "Parts washing" brush - useful for small areas and
              crevices

    C.   Rubber gloves and rain gear, if desired

    D.   Garden hose


PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

    A.   Fill one or two buckets with about two gallons of water.

         NOTE:  Water washing alone will remove most common dirt
         and grime; however, at times supplemental materials will
         be needed to remove the deposits.

         1.   For Bronze:  Add BTA to wash water to make a 1 to
              3% solution of BTA to water.
         
         2.   For Detergent Washing:  Add 1 to 3 ounces of
              detergent per gallon of water.

    B.   Beginning at the top and gradually working down, scrub
         the metal surface lightly with the fiber brush to remove
         any superficial deposits.  Take care to avoid scratching
         or otherwise damaging the protective coating.

    C.   Thoroughly rinse the surface with clean, clear water.

         1.   For Cast Iron:  Rinse with 2% aqueous solution of
              "Versene".

    D.   Dry with clean, lint-free toweling or rags.

    E.   For tenacious mineral deposits or exudations of core
         material, treat locally with gentle abrasion using very
         fine bronze wool.  Exercise great care to avoid damaging
         the coating and patina.

                         END OF SECTION