EPOXY PATCHING CRACKS IN LIMESTONE


PART 1---GENERAL

1.01 SUMMARY

     A.   This procedure includes guidance on patching cracks in
          limestone using an epoxy resin.  This type of repair is
          suited for dormant (inactive) cracks no larger than 3/8"
          wide.

     B.   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 QUALITY ASSURANCE

     A.   Contractor: A skilled firm with not less than ten (5)
          years experience in masonry repointing and restoration.
          The Contractor shall be required to submit references for
          five (5) successfully completed projects of similar
          nature.

     B.   Source of Material: Obtain materials for stone
          restoration from a single source for each type of
          material required, to ensure match of quality, color,
          pattern, and texture.
     
1.03 PROJECT/SITE CONDITIONS

     A.   Environmental Requirements:  Perform work only in dry and
          otherwise favorable weather conditions. Protect repaired
          masonry against freezing or excessively rapid drying for
          at least 48 hours after being laid. Do not repoint mortar
          joints or repair masonry unless air temperatures are
          between 40 F (4 C) and 80 F (27 C) and will remain so for
          at least 48 hours after completion of work.


PART 2---PRODUCTS

2.01 MANUFACTURERS

     A.   Akemi Plastic, Inc.
          Eaton Rapids, MI

     B.   Euclid Chemical Company
          Cleveland, OH

     C.   E-Poxy Industries, Inc.
          Ravena, NY

2.01 MATERIALS

     A.   Epoxy-Based Stone Repair Adhesive: A commercially
          available, two component, moisture insensitive, high
          modulus, low viscosity, epoxy resin-formulated for
          penetrating deep into thin masonry cracks, such as
          "Akepox" (Akemi Plastic, Inc.), "Eucopoxy Injection
          Resin" (Euclid Chemical Company), "Eva-Pox Injection
          Resin #4" (E-Poxy Industries, Inc.), or approved equal.

     B.   Single Source Responsibility: Provide epoxy resin,
          hardener and solvent produced by the same manufacturer.

     C.   Acetone (C3H6O):

          1.   A volatile fragrant flammable liquid ketone used
               chiefly as a solvent and in organic synthesis.

          2.   Other chemical or common names include Dimethyl
               ketone; Propanone

          3.   Potential Hazards:  VOLATILE AND FLAMMABLE SOLVENT

          4.   Available from chemical supply house or hardware
               store.

     D.   Limestone Dust

     E.   Clean, potable water

2.03 EQUIPMENT

     A.   Syringe

     B.   Stiff bristle brushes (non-metallic)


PART 3---EXECUTION

3.01 PREPARATION

     A.   Protection:

          1.   Take whatever precautions are necessary to protect
               the existing building from damage resulting from
               work under this section.

          2.   Prevent mortar and patching compounds used in
               repointing and repair work from staining face of
               surrounding masonry and other surfaces. Remove
               immediately mortar and patching compounds in
               contact with exposed masonry and other surfaces.

          3.   Improper use of chemicals may constitute a health
               hazard. Refer to manufacturer's Material Safety
               Data Sheets for hazard data, special protection for
               use and precautions to be taken in handling and
               storage. Comply with manufacturer's recommendations
               for proper use of chemicals.

3.02 ERECTION, INSTALLATION, APPLICATION

     A.   Thoroughly clean dust, dirt and debris from crack.

     B.   Wipe surfaces to be bonded with acetone and allow to dry
          thoroughly.

     C.   Thoroughly and completely mix resin and hardener (2
          minutes). Mix at low speeds to minimize entrapped air.
          Blend the epoxy adhesive to match color matrix of
          adjacent limestone by adding color limestone dust or
          pigment.

     D.   Mask stone surfaces adjacent to crack to prevent staining
          of the limestone during repair operation.

     E.   After mixing, inject epoxy into cracks with a syringe and
          allow to seep in. Continue to apply material until crack
          is full. Sprinkle limestone dust on epoxy adhesive to
          mask crack.

     F.   Clean tools and any tape residue with acetone or solvent
          specifically formulated for the particular product used.

                          END OF SECTION