Repairing Hairline Cracks And Small Gouges In Marble
- Procedure code:
- National Capitol Region Specifications - State Department
- Last Modified:
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.
- This procedure includes guidance on filling narrow cracks, holes and gouges in interior marble.
- 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).
- Akemi Plastics, Inc. www.akemina.com
- Eastern Marble & Granite Supply Company www.easternmarble.com
- Polyester Filler: Knife Grade Polyester-Based Adhesive:
"Akemi Marmorkitt 1000 Platinum" (Akemi Plastic, Inc.,), or "Italian Craftsman Polyester Adhesive"(Eastern Marble & Granite Supply Company), or approved equal.
NOTE: Selected filler should NOT contain materials that may absorb into the marble and cause staining. Test in an inconspicuous area.
- Polishing Compound: An acid-free abrasive compound containing no caustic or harsh fillers or ingredients with natural resins added, manufactured specifically for polishing interior marble surfaces, such as R52B (Eastern Marble Supply Company), or approved equal.
- Water: Clean and free of amounts of oils, acids, alkalies, salts, organic materials, or other substances that may be deleterious to mortar or any metal in the wall.
- Hacksaw Blade
- Hand-held Water Bottle
- Caulking gun
- Stiff bristle brushes (non-metallic)
- Soft, nylon bristle brushes
- Water feed grinder
3.01 ERECTION, INSTALLATION, APPLICATION
- Using a chisel or hacksaw blade, carefully remove unsound marble material and old patching material from cracks and holes to expose sound marble material for contact with polyester resin patch.
- Brush, vacuum or flush cracks and holes to remove dirt and loose debris.
- Allow to dry thoroughly.
- Using a caulking gun or spatula, fill narrow cracks, holes, and gouges with polyester filler, colored to match adjacent marble and honed or polished to match marble finish. Tape around the work area to prevent staining of the marble during filling operation. Surfaces shall be true and level. Remove tape residue with appropriate solvent to produce the specified finish.
- Allow patching material to cure for period recommended by manufacturer.
- Grind marble down until an even plane is achieved. Feather out to unaffected surface as required to avoid marble having dished appearance. Use right angle water feed grinder with successively finer diamond disks (#60 to #3500) or silicon carbide grinding stones (36 to 400 grit).
- Polish to match existing sheet of marble. Use acid-free aluminum oxide polishing compound with felt pad.
CAUTION: USE NO POLISHING COMPOUNDS CONTAINING FLUORIC ACID AS IT WILL ETCH THE MARBLE SURFACE RESULTING IN A DIMINUTION OF GLOSS.