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Historic Preservation - Technical Procedures

Spectitle:

Repairing Loose Cast Iron Joints

Procedure code:

0572502R

Source:

Outdoor Sculpture Manual - Cpb

Division:

Metals

Section:

Ornamental Metal Castings

Last Modified:

02/24/2012

Details:

Repairing Loose Cast Iron Joints



REPAIRING LOOSE CAST IRON JOINTS


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure provides guidance on inspecting,
         tightening and repairing connections of cast iron
         features that have become loose or are deteriorated.  

         NOTE:  THIS PROCEDURE SHOULD BE PERFORMED ON AN AS NEEDED
         BASIS BASED ON THE RESULTS OF SEMI-ANNUAL INSPECTIONS.


PART 2---PRODUCTS

2.01 MATERIALS
   
    A.   Nuts and bolts of appropriate sizes to match existing or
         as required.  Use AISI 316 stainless steel or bronze
         connectors where possible.

    B.   Mineral spirits, navel jelly, etc. as required for
         removing deteriorated paint and corrosion.  For guidance
         on paint removal from wrought iron, cast iron and steel,
         see 05010-05-R, 05010-16-R and 05010-17-R.

    C.   Sandpaper and/or steel wool as required to remove
         corrosion.

    D.   Molten lead

    E.   New cast or wrought iron, etc. for welded repairs.

    F.   High quality, paintable caulk
   
2.02 EQUIPMENT

    A.   Wrenches, pliers, screwdrivers

    B.   Welding equipment

    C.   Stiff bristle brush


PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION
   
    A.   Simple loose connections:

         1.   Locate loose joints and bolts, nuts and screws,
              etc.

         2.   Carefully remove loose connectors and clean them of
              all corrosion and loose debris using sandpaper,
              steel wool, or a stiff bristle brush.  Clean holes
              and surfaces of feature as well.
   
         3.   Reinstall connectors in original location and
              tighten connections which are functional.
   
    B.   Deteriorated connections requiring replacement
         screws/bolts:

         1.   Remove connectors which are severely deteriorated
              and frozen, for replacement with new.
   
         2.   Determine the number and size of required new
              connectors.

         3.   Clean holes and surfaces of feature of all rust and
              loose debris.

         4.   If hole has corroded, redrill as required to
              standard bolt or screw size.

         5.   Insert new stainless steel or bronze connector as
              required to secure connection.

    C.   Wobbly newel posts or similar features:

         1.   If entire assembly is wobbly, carefully dismantle
              feature.  Mark pieces as required in inconspicuous
              spot for easy reassembly.

         2.   Inspect center threaded rod or anchor pin(s) and
              remove from setting hole in base.  

         3.   Clean base of rod or pin of all corrosion and loose
              paint.  Blow-out hole with air blast to clean out
              debris.

         4.   Repaint base of rod or pin as required before
              placing it back into setting hole and packing hole
              with molten lead.

         5.   Backprime all pieces of feature and reassemble.  

         6.   If required to restore and/or improve stability of
              newel, weld small wrought or cast iron tabs at base
              of newel (two tabs per face).

         7.   Thread small stainless steel or bronze screws or
              bolts through tabs into masonry base and fill holes
              with molten lead.

    D.   Seal all seams with high quality, paintable caulk.  DO
         NOT USE CONCRETE TO FILL ANY VOIDS.  DO NOT SEAL WEEP
         HOLES OR DRAINAGE HOLES.

    E.   Paint feature as required.  For guidance on painting cast
         iron see 05010-13-S and 09900-07-S.

                         END OF SECTION