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EPOXY PATCHING SMALL CRACKS AND HOLES IN MARBLE


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on patching small cracks
         and holes in marble with a two-component epoxy resin.

    B.   This procedure is appropriate for cracks smaller in width
         than 1/8" and for holes smaller in diameter than 2".

    C.   Small cracks and holes in marble or other stone may be
         caused by impact damage, natural flaws in the stone or
         work on the stone.  A common cause of holes and cracks is
         the attachment of fixtures and signage to walls.  The
         later removal of such attachments leaves unsightly anchor
         holes which should be plugged or patched.

    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).


PART 2---PRODUCTS

2.01 MATERIALS

    A.   Patching Resin:  Manufacturer's standard 2-component
         epoxy resin, designed specifically for patching or
         bonding of marble units.

         1.   Factors to consider when selecting an epoxy should
              include permeability, absorption, thermal expansion
              coefficients and ultraviolet lighting conditions.

    B.   Aggregate for Epoxy:  Ground marble dust to match color
         of existing marble.

    C.   Clean, potable water

2.02 EQUIPMENT

    A.   Hacksaw Blade

    B.   Chisels

    C.   Hand-held Water Bottle

    D.   Steel Trowel

    E.   Caulking gun

    F.   Stiff bristle brushes (non-metallic)

    G.   Resurfacing Screens for Honed Finish:  A fine grit screen
         manufactured specifically for restorative type cleaning
         and resurfacing of honed marble surfaces.

    H.   Grinding Stones for Honed Finish:  Fine grit emery stones
         manufactured specifically for restorative type grinding
         and resurfacing of honed marble surfaces.

    I.   Soft, nylon bristle brushes


PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

    NOTE:  THIS PROCEDURE IS APPROPRIATE FOR CRACKS SMALLER IN
    WIDTH THAN 1/8" AND FOR HOLES SMALLER IN DIAMETER THAN 2".
    THE MAXIMUM SIZE OF THE REPAIR SHOULD BE ADJUSTED ACCORDING TO
    THE TYPE OF MARBLE AND THE PROPOSED APPEARANCE.

    A.   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
         epoxy patch.  

    B.   Brush, vacuum or flush cracks and holes to remove dirt
         and loose debris.

    C.   Mix 2-component epoxy resin with marble dust aggregate to
         create a paste with a consistency suitable for
         application (based on RHPO approval).  Use marble dust
         from stone pieces of the same type, color, etc.

    D.   Using a caulking gun or spatula, apply patching material
         in cracks and holes as recommended by manufacturer to
         conform to adjacent marble surfaces.

    E.   Allow patching material to cure for period recommended by
         manufacturer.

    F.   Once hardened, grind and polish surface of patching
         material to match surface characteristics of adjacent
         marble.

                             END OF SECTION