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Historic Preservation - Technical Procedures

Spectitle:

Cleaning And Painting Cast Iron Lamps

Procedure code:

1651005R

Source:

National Capitol Region Specifications

Division:

Electrical

Section:

Lighting Fixtures

Last Modified:

02/24/2012

Details:

Cleaning And Painting Cast Iron Lamps



CLEANING AND PAINTING CAST IRON LAMPS


CAUTION:  MECHANICAL/ABRASIVE METHODS OF CLEANING MAY DAMAGE
HISTORIC FABRIC.  THIS METHOD OF CLEANING SHOULD BE PERFORMED ONLY
BY AN EXPERIENCED PROFESSIONAL AND ONLY UPON APPROVAL FROM THE
REGIONAL HISTORIC PRESERVATION OFFICER.

THE CLEANING OR STRIPPING OF METALS MAY INVOLVE THE USE OF
ABRASIVES, LIQUIDS OR SOLVENTS WHICH MAY SPLASH OR RUN OFF ONTO
ADJACENT MATERIALS.  TAKE SPECIAL CARE TO PROTECT ALL ADJACENT
MATERIALS, AND DO NOT USE THIS PROCEDURE ON METALS OTHER THAN
THOSE SPECIFIED IN THE SUMMARY.  

BEFORE UNDERTAKING ANY PROJECT INVOLVING PAINT REMOVAL, APPLICABLE
STATE AND FEDERAL LAWS ON LEAD PAINT ABATEMENT AND DISPOSAL MUST
BE TAKEN INTO ACCOUNT AND CAREFULLY FOLLOWED.  STATE AND FEDERAL
REQUIREMENTS MAY AFFECT OPTIONS AVAILABLE TO OWNERS ON BOTH PAINT
REMOVAL AND REPAINTING.  THESE LAWS, AS WELL AS ANY REQUIREMENTS
PROHIBITING VOLATILE ORGANIC COMPOUNDS (VOCs), SHOULD BE REQUESTED
FROM THE STATE HISTORIC PRESERVATION OFFICER IN EACH STATE.  (From
Preservation Brief 28, "Painting Historic Interiors".)  REGULATORY INFORMATION MAY
ALSO BE REQUESTED FROM THE ENVIRONMENTAL PROTECTION AGENCY (EPA)
REGIONAL OFFICE AND/OR THE STATE OFFICE OF ENVIRONMENTAL QUALITY.


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on filling open cracks,
         cleaning and painting iron lamp standards.

    B.   For information on inspecting for cast-iron failures, see
         05010-01-S.  For general information on the
         characteristics, uses and problems associated with cast-
         iron, see 04720-01-S.
   
    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).

1.02 REFERENCES

    A.   Steel Structures Painting Council (SSPC), 4400 Fifth
         Avenue, Pittsburgh, PA 15213.

1.03 PROJECT/SITE CONDITIONS

    A.   Environmental Requirements:  Do not apply finish material
         when temperature is below 50 F. and falling.  Do not
         apply paint on surfaces in direct sunlight.  Do not apply
         finishes in spaces where dust is being generated, which
         would speck the finish.


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   Benjamin Moore, Co.
         51 Chestnut Ridge Road
         Montvale, NJ  07645
         201/573-9600

    B.   The Sherwin Williams Co.
         101 Prospect Ave. N.W.
         Cleveland, OH  44101
         216/566-2000

    C.   Martin Senour
         800/542-8468

    D.   Devcon Corporation
         30 Endicott Street
         Danvers, MA  01923
         800/933-8266

2.02 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.   Mineral spirits:

         1.   A petroleum distillate that is used especially as a
              paint or varnish thinner.

         2.   Other chemical or common names include Benzine* (not
              Benzene); Naphtha*; Petroleum spirits*; Solvent
              naphtha*.

         3.   Potential Hazards:  TOXIC AND FLAMMABLE.

         4.   Safety Precautions:

              a.   AVOID REPEATED OR PROLONGED SKIN CONTACT.

              b.   ALWAYS wear rubber gloves when handling
                   mineral spirits.

              c.   If any chemical is splashed onto the skin,
                   wash immediately with soap and water.

         5.   Available from construction specialties
              distributor, hardware store, paint store, or
              printer's supply distributor.

    C.   Emery paper

    D.   Flint sandpaper

    E.   Fine steel wool

    F.   600 grit aluminum oxide

    G.   Rust remover solution containing orthophosphoric acid.
         Several are available in gel form from retail outlets.

    H.   Soft rags

    I.   Clean, potable water

    J.   Sealant:  Polysulfide sealant, color as approved by RHPO.

    K.   Metal Filler:  Steel filled two part epoxy metal filler,
         putty grade, such as "Plastic Steel A" (Devcon
         Corporation), or approved equal.

    L.   Paint for Metal Paint and Finish Products, such as those
         by Benjamin Moore, Sherwin Williams, Martin Senour, or
         approved equal.  See also 05010-13-S for general
         information on the advantages and limitations of various
         paint and primer types.

         1.   Paint products shall be fresh and well ground;
              shall not settle readily, cake or thicken in the
              container; shall be broken up readily with a paddle
              to a smooth consistency; and shall have easy
              application properties.  

         2.   Other painting materials, such as linseed oil,
              turpentine, mineral spirits, and miscellaneous
              thickeners, shall be the highest quality of an
              approved manufacturer.

         3.   Colors: Primer coats to be clearly different in
              color from each other; base coat to be clearly
              different from primer or finish coat; finish coat
              to be approved by RHPO.

         4.   Dry Film Thickness: Each coat to be 2 mils.

2.03 EQUIPMENT

    A.   Rubber gloves

    B.   Eye and skin protection

    C.   Paint scrappers and putty knives

    D.   Ball peen hammer

    E.   Sanding blocks, sanding sponges, sanding wheels

    F.   Wire brushes

    G.   Stiff natural bristle brushes

    H.   Rotary wire wheels

    I.   Proper, heavy-duty extension cords

    J.   Air-abrasive cleaning equipment (80-100 psi) for use with
         fine grit dry and wet abrasives.  Consult RHPO.

    K.   Water hose


PART 3---EXECUTION

3.01 EXAMINATION

    A.   Before work is begun on removing the existing paint film
         or otherwise preparing the surface all sources of excess
         moisture shall be determined and repaired as required.  

    B.   Execute test samples of the cleaning methods specified in
         this procedure to determine which method(s) are to be
         used.  Sample areas shall be selected by the RHPO and
         shall include at least one ornamental area and one flat
         area, or as necessary to include all surface types likely
         to be encountered in this work.

    C.   Method(s) used in the actual cleaning shall be the one(s)
         which provide the necessary level of cleanliness with the
         least amount of surface alteration.  Final selection of
         methods shall be made by the RHPO.

3.02 PREPARATION

    A.   Protection:

         1.   Protect adjacent surfaces, including grass, shrubs
              and trees with paper, drop cloths and other means.
              Items not to be painted which are in contact with
              or adjacent to painted surfaces shall be removed or
              protected prior to surface preparation and painting
              operations.  All methods of enclosure and
              protection should be approved by the supervisor.

         2.   Work area shall be sealed to prevent the spread of
              dust, debris and water beyond the work site, and to
              assist in the collection of contaminants.

         3.   Provide protection boards to vulnerable decorative
              work and maintain for the duration of operations.

         4.   All waste material shall be collected at the end of
              each work day and properly disposed of.  It is
              considered Hazardous Waste.

         5.   After each days paint removal work is complete,
              area shall be vacuumed with machines equipped with
              HEPA (High Efficiency Particulate Air) filters to
              insure all lead dust has been removed.

    B.   Surface Preparation:  Determine surfaces to which
         painting and finishing are to be applied are even,
         smooth, sound, clean, dry and free from defects affecting
         proper application.  Correct or report defective surfaces
         to Contracting Officer.

3.03 ERECTION, INSTALLATION, APPLICATION

    A.   Metal Cleaning, General:

         NOTE:  REMOVE ONLY AS MUCH PAINT AND RUST EACH DAY AS CAN
         BE PRIMED THAT SAME DAY.  BARE IRON AND STEEL WILL BEGIN
         TO RUST AGAIN WITHIN A MATTER OF HOURS.  IT SHOULD NOT BE
         ALLOWED TO SIT UNPROTECTED OVERNIGHT.

         1.   Remove all paint and scale from all surfaces to
              bare metal.

         2.   Dismantle iron lamp standards.

    B.   Mechanical/Abrasive Rust/Paint Removal:  OBTAIN RHPO
         APPROVAL BEFORE PROCEEDING WITH WORK.

         1.   To determine the degree of deterioration and the
              level of paint removal required, clear away all
              dust and debris followed by rub-down with mineral
              spirits.

         2.   To remove light rust and flaking, peeling paint:

              a.   Begin with emery paper or aluminum oxide
                   sandpaper.

              b.   Use scrapers to get under loose paint and into
                   crevices.

              c.   Use a wire brush, or an electric drill with a
                   special wire brush or rotary sandpaper whip
                   attachment if above two methods do not remove
                   paint.

    C.   Air-abrasive Paint Removal:  OBTAIN RHPO APPROVAL BEFORE
         PROCEEDING WITH WORK.

         NOTE:  WHILE AIR ABRASIVE CLEANING (COMMONLY KNOWN AS
         SANDBLASTING) IS DESTRUCTIVE FOR SOFTER BUILDING
         MATERIALS, IRON, A HARD MATERIAL WITH A NATURAL UNEVEN
         SURFACE, WILL NOT BE NOTICEABLY DAMAGED BY ITS CAREFUL
         USE.

         CAUTION:  DO NOT USE AIR-ABRASIVE CLEANING METHODS IN THE
         FOLLOWING SITUATIONS:  1)  ON THIN SECTIONS OR FINE,
         INTRICATE DETAILS OF WROUGHT IRON FEATURES.  2)  ON ZINC
         AND GALVANIZED IRON AND STEEL.  3)  ON FEATURES FOR WHICH
         THE ORIGINAL SURFACE TEXTURE IS AN INTEGRAL PART OF THE
         DESIGN (AIR-ABRASIVE CLEANING WILL ALTER ORIGINAL SURFACE
         TEXTURE AND APPEARANCE).  4)  ON STAINLESS STEEL
         FEATURES.

         1.   Air pressures at the compressor shall be between 40
              psi to 70 psi.

         2.   Grit size shall be in the range of #10 to #45, i.e.
              copper slag.  Other abrasives, such as ground
              walnut shells, or other abrasive methods such as
              glass bead peening, may also be appropriate but
              should be performed only under the direction of an
              architectural conservator and/or the RHPO.

         3.   A pencil-point nozzle shall be used to allow more
              complete control.  Nozzle shall allow for
              independent control over air, water and abrasive
              and should be held no closer than 12" from the
              surface to be cleaned.

         4.   Flush all surfaces with water to remove all traces
              of slurry and spent abrasive.  Final rinse shall
              contain rust inhibitor with no more than 5000 ppm.

              CAUTION:  LARGER CONCENTRATIONS OF RUST INHIBITOR
              WILL RESULT IN THE DEPOSITION OF SALTS ON THE METAL
              SURFACES WHICH WILL CAUSE THE PAINT TO PEEL.

         5.   Dry surfaces immediately, especially any horizontal
              surfaces or water traps which might collect water.

    D.   Prime as soon as possible after surfaces have been dried
         but before rust has a chance to reform.  See 05010-13-S
         for general information describing paints and primers for
         cast-iron.  Apply second prime coat after first has dried
         completely.  Secure approval of surface preparation and
         each coat prior to proceeding with the next.

    E.   Reasssemble cast iron lamp standards.  Seal all open
         joints between metal elements and metal and masonry with
         polyethylene backer rods and polysulfide sealant. Joint
         shall be concave with smooth finish.

    F.   Fill all holes, depressions and cracks with metal filler
         and sand to conform with surrounding contours.  See
         05010-12-R for guidance.

    G.   Prime and paint all surfaces.  Brush apply two finish
         coats of paint.

         1.   Apply material evenly without runs, sags, or other
              defects.  Work each coat onto the material being
              coated at an average rate of coverage recommended.
              Cover surfaces complete to provide uniform color
              and appearance with a minimum of dry film thickness
              of 2 mils.  Make edges of paint adjoining other
              materials or colors sharp and clean, and without
              overlaps.

         2.   Drying time:  Minimum time as recommended.  Do not
              apply succeeding coats until the undercoat is
              thoroughly dry.

         3.   For guidance see 05010-13-S "Primers and Paints for
              Wrought Iron, Cast Iron and Steel", 05010-18-R
              "Applying a Sacrificial Coating to Wrought Iron,
              Cast Iron and Steel", and 09900-07-S "General
              Guidelines for Painting Exterior and Interior
              Surfaces".

3.04 ADJUSTING/CLEANING

    A.   Cleanup:  Remove all paint where it has spilled or
         spattered.  Do not drip any paint on stone.  No chemical
         cleaners allowed.

3.05 PROTECTION

    A.   Protect cleaned or final finishes from damage during
         building or project cleaning period by use of temporary
         protective coverings approved by RHPO.  Remove protective
         covering at time of Substantial Completion.

                         END OF SECTION