Technical Procedures Disclaimer
Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.
We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.
A. This procedure includes guidance on repairing leaded glass, and includes information on repairing lead cames and structures, replacing deteriorated lead cames, and replacing deteriorated support structures.
B. This work generally requires a specialist in stained and leaded glass repair.
C. See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections:
- Safety Precautions
- Historic Structures Precautions
- Quality Assurance
- Delivery, Storage and Handling
- Project/Site Conditions
- Sequencing and Scheduling
- 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. Product Data: Submit manufacturer's technical data for each product indicated including recommendations for their application and use. Include test reports and certifications substantiating that products comply with requirements.
B. Restoration Program: Submit written program for each phase of restoration process including protection of surrounding materials on building and site during operations. Describe in detail materials, methods and equipment to be used for each phase of restoration work.
C. Samples: Submit for verification purposes, prior to mock- up erection, samples of the following:
- Each type of replacement glass= .
- Each type of lead came.
1.03 QUALITY ASSURANCE
A. Field Samples: Prior to start of leaded glass restoration work, prepare the following sample panels in building where directed by RHPO. Obtain RHPO's acceptance of visual qualities before proceeding with the work. Retain acceptable panels in undisturbed condition, suitably marked, during construction as a standard for judging completed work.
- Cleaning: Demonstrate materials and methods to be used for cleaning on sample panel of approximately 9 sq. Ft. in area.
- Leaded Glass Repair: Prepare sample panel to demonstrate quality of materials and workmanship of each type of leaded glass indicated to be repaired and replaced.
1.04 DELIVERY, STORAGE AND HANDLING
A. Packing and Shipping: Protect materials during transit, delivery, storage and handling to prevent damage, soiling and deterioration.
A. Glass: Provide new glass to match opacity, color, thickness, texture, pattern and other aesthetic characteristics of existing glass.
B. Lead Came: Provide new H and U-shape lead came to match size, profile and other aesthetic characteristics of existing lead came.
C. Putty: Standard putty manufactured specifically for leaded glass work.
D. Braces and Other Accessories: Provide new to match existing.
E. Solder: 60% lead and 40% tin composition.
F. Cleaner: Manufacturer's standard ammonia-base cleaning solution specifically designed for cleaning of leaded glass surfaces.
G. Water for Cleaning: Clean, potable, free of oils, acids, alkalis, salts and organic matter.
H. Clean, soft cloths
A. Stiff bristle brush
3.01 ERECTION, INSTALLATION, APPLICATION
A. Repairing Lead Cames and Structures:
- Soldering Joints: Solder new joints or re-solder deteriorated or broken joints as follows:
- Clean patina off lead by scraping surface of came with a sharp blade or file to expose shiny lead at least AC" either side of joint.
- Apply flux to surface of came.
- Apply solder to joint with a soldering iron.
- Darken new solder by treating with tin oxide.
- Replacing Lead Cames: Install new lead cames to replace damaged or deteriorated cames as follows:
- Carefully pry up all edges of came around pieces of glass that are seated in length of came to be replaced. Do not scratch or other= wise damage glass.
- Remove pieces of glass and cut out section of came to be replaced at joints.
- Install new strip of came and solder joints as described above.
- Pry up edges of new came and reinstall pieces of glass using a thin layer of putty in channels of cames to hold glass tightly in place.
- Press lead cames down to flat position and repair any broken or damaged solder joints.
- Darken new cames by treating with tin oxide.
- Repairing Support Structures: Replace deteriorated support members or supplement existing support members as required as follows:
- Prior to repairing support structures, provide braces and temporary support as required to protect leaded glass work from deflection or other kind of damage.
- Carefully remove deteriorated support members.
- File or scrape old solder deposits from surfa= ces of lead came.
- Repair leaded glass as required to remove bowing or warping.
- Install new support members and solder and fasten to leaded glass.
- Clean all leaded glass surfaces.
- Vacuum or brush loose dirt and dust from surfaces of glass.
- Wash both sides of glass using a clean cloth and cleaner.
- Rinse both surfaces thoroughly using a clean cloth and clean water to completely remove dirt and cleaner residue. Change rinse water frequently.
- Repeat process as required to produce effect established by mock-up.
- Wipe the surface with a dry clean cloth to prevent streaking.
A. Protect leaded glass from damage during construction operation.
B. At completion of project, remove any protective coverings and re-clean any soiled surfaces using procedures and materials described herein.