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Historic Preservation - Technical Procedures |
Spectitle: | Repairing Brass Window And Door Finish Hardware |
Procedure code: | 0871004R |
Source: | Hspg Prepared For Nps - Sero |
Division: | Doors And Windows |
Section: | Finish Hardware |
Last Modified: | 02/24/2012 |
Details: | Repairing Brass Window And Door Finish Hardware REPAIRING BRASS WINDOW AND DOOR FINISH HARDWARE PART 1---GENERAL 1.01 SUMMARY 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). 1.02 DEFINITIONS 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. 1.03 SYSTEM DESCRIPTION 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. 1.04 DELIVERY, STORAGE, AND HANDLING 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 piece. 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. 1.05 SEQUENCING AND SCHEDULING 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. 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 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 screws 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 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. d. Available from construction specialties distributor, hardware store, paint store, or printer's supply distributor. 2.02 EQUIPMENT 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 PART 3---EXECUTION 3.01 EXAMINATION 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. 3.02 PREPARATION 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 winds. 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. 3.03 ERECTION, INSTALLATION, APPLICATION 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 hardware. 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 hardware. 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 |