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Historic Preservation - Technical Procedures


Repairing Brass Window And Door Finish Hardware

Procedure code:



Hspg Prepared For Nps - Sero


Doors And Windows


Finish Hardware

Last Modified:



Repairing Brass Window And Door Finish Hardware




    A.   This procedure includes guidance on repairing brass
         window and door hardware where these are deteriorated
         (rusted and corroded) and where there are missing
         elements.  For guidance on cleaning brass hardware, see
         05010-03-P and 08700-02-R.

    B.   Safety Precautions:

         1.   All workers must be protected from the effects of
              chemicals during the cleaning/repairing operations.

         2.   Some chemicals suggested for brass maintenance are
              flammable, toxic, or both.  As a general rule,
              avoid skin contact and inhalation of any chemical.
              Rubber or plastic gloves should be worn when
              handling hazardous (flammable or toxic) chemicals.
              Follow storage and handling procedures printed on
              the container labels of the cleaning solutions,
              provide good ventilation while working, and
              thoroughly wash hands after completion of the work.

         3.   Workers should take precautions to prevent epoxies
              and their components from contacting the skin.
              Provide protective clothing which must be worn and
              protective creams for exposed skin areas.
              Accidental contact with unprotected skin to these
              materials must be treated immediately by washing
              with soap and water, never with solvents.  Exercise
              care to avoid skin contact to tool cleaning
              solvents and to provide adequate ventilation for
              clean-up operations.

    C.   Historic Structures Precautions:

         1.   As with all other historic fabric, brass will have
              a historic importance which must be identified at
              an early stage.  The item's merit, in terms of age,
              uniqueness of design, materials, size,
              technological development, association with persons
              or events, exceptional workmanship or design
              qualities, must be understood before decisions
              regarding repair, maintenance and preservation can
              be made.  

         2.   Remove existing brass hardware components without
              damage to the material itself, adjacent materials,
              or substrate.  Carefully label as to location.
              Clean and reinstall carefully.

         3.   When choosing the brass hardware to be replaced,
              the RHPO should be consulted to provide information
              about how to match for color and type of the metal.

    D.   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).


    A.   Brass is an alloy resulting from the mixture of copper
         and zinc.  The color of brass varies, depending upon the
         amount of zinc in the mixture and whether or not other
         metals are added.  Brasses with relatively large amounts
         of zinc are yellow in color.  The addition of aluminum
         makes a light golden color.  A small percentage of
         manganese produces a bronze-like color.  The addition of
         nickel results in a silvery metal called nickel silver.

    B.   Brass is a hard, durable, and utilitarian metal, making
         excellent castings.  It can be worked hot, and extruded.
         A very workable brass can be made by adding a little
         lead.  The process of extrusion is most commonly used,
         especially to produce large architectural pieces,
         including doors and elevators, and in such elements as
         window frame sections, hand rails, and balustrades.
         Brass was also used for architectural members because of
         its corrosion resistance.

    C.   In colonial America, public buildings and fine homes
         often had brass hinges, door knobs, door knockers,
         chandeliers, and fireplace and irons; however, almost all
         of the brass hardware was imported from England and
         America, brass was used for light fixtures, plumbing
         fixtures, and every type of builder's hardware.  Polished
         brass was a favorite for commercial buildings handrails,
         stair railings, elevators, lobby furniture, building
         directories, etc.


    A.   The natural beauty of the brass should be well preserved.
         The hardware should be intact, in good condition, without
         any signs of deterioration (corrosion by the action of
         the atmosphere and acids derived from organic growths,
         scaling, pitting, or severe rust).  There should be no
         missing elements.  They should be securely mounted, and
         properly set in the window or door frame, and there
         should not be evidence of movement if it is pushed.  Any
         paint on brass must be continuous to be effective - it
         should not be peeled exposing the bare metal.


    A.   Packing and Shipping:  For replaceable material: protect
         brass hardware from damage at all times during handling,
         installation, and operation of the building.

    B.   Acceptance at Site:

         1.   New metal parts shall be delivered on the job
              carefully packed.  Inspect each piece immediately
              before installation, and do not use the pieces
              which have observable surface damage.

         2.   Manufacturer's delivery or job markings on the
              brass, and adhesives for manufacturer's labels,
              shall either be a neutral or slightly acidic
              material.  In no case shall such material be
              alkaline; any staining of the metal by alkaline
              materials will cause for the rejection of the

    C.   Storage and Protection:

         1.   Brass hardware should be stored as to protect from
              surface damage at all times, carefully packed and
              should remain so from the time of delivery until
              set.  Keep uninstalled metal components in a dry,
              rust-free storage facility.

         2.   Salvaged historic material shall be carefully
              packed and stored under cover and in the building
              away from working or traffic areas.  Mark salvaged
              material with the year of removal.


    A.   Preventive  Maintenance and Repair activities should be
         scheduled during appropriate environmental conditions to
         avoid weather related failures.

    B.   When cyclical maintenance work requires the use of high
         ladders and other access equipment, perform as many work
         items as possible.



    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 cleaning and 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.   Hardware:

         1.   Butt hinges complete with all necessary screws

         2.   Mortise locks and latches complete with lock body,
              rose, spindle, knobs, key plate, latch and strike
              including all necessary screws and fastenings

         3.   Sash lifts and locks complete with all necessary

         4.   Sash counterweights complete with track, pulley,
              cord and weight and all necessary screws

         5.   Metal thresholds complete with all necessary
              counter-sunk screws

         6.   Spring brass weatherstripping, 1 1/8" x .008", with
              hemmed edges complete with screws or springs
         7.   Replacement screws and bolts

    B.   Emery paper, sandpaper (useful for smaller jobs or final
         feathering of high paint edges, corners, or hard to reach
         places), or fine steel wool.

    C.   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

         3.   Potential Hazards:  TOXIC AND FLAMMABLE.

         4.   Safety Precautions:


              b.   ALWAYS wear rubber gloves when handling
                   mineral spirits.

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

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


    A.   Wiping cloths

    B.   Eye and skin protection

    C.   Gloves and protective gear

    D.   Brushes

    E.   Putty knife

    F.   Scrapers
    G.   Wire brush

    H.   Screwdriver

    I.   Electric drill

    J.   Electric wire brush



    A.   Determine the cause and extent of the problem.  Determine
         the age of the hardware and examine the condition of the
         entire surface.  Inspect for:

         1.   Wear - especially moving parts.

         2.   Parts - which have failed or which are unsecured,
              broken, cracked, missing, distorted, or loose
              (check screws and bolts).

         3.   Paint - coating failures such as chips, peeling,
              checks, bubbling, and wear.

         4.   Rust corrosion - caused by moisture, deicing salts,
              acids, soils, gypsum plasters, magnesium
              oxychloride cements, ashes, clinkers, and sulfur
              compounds.  Determine the source of the moisture
              which causes the deterioration.

         5.   Determine if the brass hardware can be salvaged.

         6.   Measure and record the dimensions of the various
              metal parts needing replacement.


    A.   Protection:

         1.   Protect all surrounding areas and surfaces during
              application of rinsing solutions and against the
              spread of dust, debris, and water.

         2.   All methods of enclosure and protection should be
              approved by the supervisor.  Protection should
              consist of non-staining plastic sheets, tarpaulins
              or burlap, secured to prevent lifting in high

    B.   Surface Preparation:

         1.   Good surface preparation is essential for good
              adhesion of a protective coating following the
              cleaning/repairing operations.  To achieve this the
              protective coating must be applied to a firm,
              stable foundation which is free of contaminants
              such as grease and water soluble salts.

         2.   Degreasing: Remove oil or grease to avoid
              subsequent preparation methods spreading the
              contamination over a wider surface.  Wash the
              features using warm water and detergent followed by
              thorough water rinsing.  Non-caustic degreasing
              agents are also available or just wipe the surfaces
              with white mineral spirits using a succession of
              clean cotton swabs.

    A.   Repair Due to Corrosion: Brass, like copper, is corroded
         by exposure to moisture, acidity caused by polluted air
         or newly-cut wood, chlorides, acetates, and ammonia.
         Excrement from birds or other animals is acidic and can
         also damage brass.

         1.   Lightly corroded areas due to moisture and/or
              standing pools of water, where the brass has not
              thinned, can be wiped and dried.  If traces of rust
              are visible, remove first with sandpaper then
              clean, dry completely, and apply a protective
              coating.  For guidance in cleaning tarnished brass,
              see 05010-32-R.  For guidance in applying a clear
              protective coating to brass features, see 05010-08-
              P.  For additional guidance in cleaning brass
              features, see 05010-03-P and 05010-10-P.

         2.   Perforated spots and thinned surrounding areas can
              be soft soldered with a patch large enough, and cut
              appropriately, to cover the entire area.

         3.   See also 08700-02-R for guidance on cleaning door

    B.   For guidance on repairing dents, scratches, holes, nicks
         and other minor imperfections, see 05010-02-R.

    C.   Missing pieces:  Missing pieces can be reproduced by
         casting.  See 08700-01-R for guidance on replicating

    D.   Deterioration of Protective Coating:

         1.   Corrosion usually begins at breaks in the surface
              and then spreads beneath it.

         2.   Completely remove protective coating from the
              damaged elements and also any rust, using the
              appropriate tools listed in the 'materials'
              section.  For guidance in removing paint or lacquer
              from brass features, see 05010-31-R.  For guidance
              in reapplying a clear protective coating to brass
              features, see 05010-08-P.

    E.   For repair work specific to sash weights and chains, see
         08760-01-R.  For repair work specific to hinges, see
         08712-01-R and 08712-02-R.

    F.   Installation of hardware:

         1.   Check function of hardware against job site
              conditions and interferences.  Adjustments and/or
              substitutions shall be made only as authorized.

         2.   Application shall be by skilled workmen, working
              with proper equipment and shall fit the work of
              others accurately, shall be applied securely and
              adjusted properly.  Exercise care not to damage
              adjacent surfaces.

                         END OF SECTION