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Historic Preservation - Technical Procedures

Spectitle:

Applying A Sacrificial Coating To Wrought Iron, Cast Iron And Steel

Procedure code:

0501018R

Source:

Maintenance, Rpr & Alteration Of Hstrc Bldgs - Gsa/Pbs

Division:

Metals

Section:

Metal Materials

Last Modified:

02/24/2012

Details:

Applying A Sacrificial Coating To Wrought Iron, Cast Iron And Steel



APPLYING A SACRIFICIAL COATING TO WROUGHT IRON, CAST IRON AND STEEL


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on applying a
         sacrificial wax or linseed oil coating to wrought iron,
         cast iron and steel features.

         NOTE:  CLEAR, NATURAL COATINGS ON EXTERIOR WROUGHT AND
         CAST IRON SURFACES ARE NOT RECOMMENDED EXCEPT IN
         EXTREMELY LIMITED CASES.  WHEN EXPOSED TO THE ELEMENTS,
         THESE TWO MATERIALS WILL RAPIDLY DETERIORATE.  CLEAR,
         NATURAL COATINGS SHOULD BE LIMITED TO ORNAMENTAL PIECES
         ONLY.  EVEN LIMITED USE REQUIRES A HIGH DEGREE OF
         DILIGENCE IN MAINTAINING THE COATING.  IDEALLY, SUCH
         COATINGS SHOULD BE LEFT TO INTERIOR WROUGHT AND CAST IRON
         SURFACES.

    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).

    C.   For guidance on cleaning and paint removal of wrought
         iron, cast iron and steel, see 05010-05-R, 05010-16-R and
         05010-17-R.


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   Butcher Polish Company
         120 Bartlett Street
         Marlborough, MA
         617/481-5700

2.02 MATERIALS

    A.   Paste wax such as Butcher's "Boston Polish Wax" or
         "Bowling Alley Wax" (Butcher Polish Company), Trewax
         Clear, or approved equal.

    B.   Beeswax

    C.   Turpentine

    D.   Linseed oil:  Available from hardware or paint store.

    E.   Emery cloth

    F.   Soft cloths

2.03 EQUIPMENT

    A.   Fiber bristle brushes (1/2 to 3/4 inches long)

    B.   Portable propane torch


PART 3---EXECUTION

3.01 PREPARATION

    A.   Before recoating, remove all traces of rust, corrosion,
         scale and old paint leaving the surface completely clean.
         For guidance on paint removal, see 05010-05-R, 05010-16-R
         and 05010-17-R.  

3.02 ERECTION, INSTALLATION, APPLICATION

    A.   Refinish with Wax:

         1.   Wax metal piece with paste wax, or a mixture of
              beeswax which has been dissolved in a bit of
              turpentine.  

              NOTE:  DO NOT USE EMULSION TYPE WAXES.

         2.   Let sit for fifteen (15) minutes.  

         3.   Buff with soft cloth.  

         4.   Rewax every one to three months depending on the
              severity of the exposure.

         -OR-

         Refinish with Wax and Linseed Oil:

         1.   Gently heat piece with a portable propane torch.  

         2.   Wipe with emery cloth.  

         3.   When cool, rub a combination of beeswax and boiled
              linseed oil into the surface with a soft cloth.

         4.   In exterior locations the beeswax and boiled
              linseed oil should be renewed yearly.

3.03 PROTECTION

    A.   Protect cleaned or final finishes from damage during
         building or project cleaning period by use of temporary
         protective coverings approved by RHPO.  Remove protective
         covering at time of Substantial Completion.

                         END OF SECTION