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Historic Preservation - Technical Procedures

Spectitle:

Refinishing A Radiator

Procedure code:

1575001R

Source:

Ohj - May 1986 And September/October 1988

Division:

Mechanical

Section:

Heat Transfer

Last Modified:

02/24/2012

Details:

Refinishing A Radiator



REFINISHING A RADIATOR


NOTE:  REFINISHING A RADIATOR IS A TEDIOUS AND TIME-CONSUMING JOB.
IF OTHER WORK REQUIRES THE REMOVAL OF THE RADIATOR, IT IS USUALLY
BETTER TO DISCONNECT AND REMOVE THE RADIATOR AT THAT TIME FOR
REFINISHING OFF SITE.  IF, HOWEVER, IT IS NOT NECESSARY TO REMOVE
THE RADIATOR, IT IS PROBABLY BETTER TO REFINISH IT IN SITU USING
ONE OF THE METHODS DESCRIBED BELOW, BECAUSE REMOVING AND
REINSTALLING A RADIATOR IS OFTEN DIFFICULT.

BEFORE UNDERTAKING ANY PROJECT INVOLVING PAINT REMOVAL, APPLICABLE
STATE AND FEDERAL LAWS ON LEAD PAINT ABATEMENT AND DISPOSAL MUST
BE CONSIDERED AND CAREFULLY FOLLOWED.  STATE AND FEDERAL
REQUIREMENTS MAY AFFECT OPTIONS AVAILABLE TO OWNERS ON BOTH PAINT
REMOVAL AND REPAINTING.  THESE LAWS, AND ANY REQUIREMENTS
PROHIBITING VOLATILE ORGANIC COMPOUNDS (VOCs), SHOULD BE REQUESTED
FROM THE STATE HISTORIC PRESERVATION OFFICER IN EACH STATE.  (From
Preservation Brief 28, "Painting Historic Interiors.")  REGULATORY INFORMATION
MAY ALSO BE REQUESTED FROM THE ENVIRONMENTAL PROTECTION AGENCY
(EPA) REGIONAL OFFICE AND/OR THE STATE OFFICE OF ENVIRONMENTAL
QUALITY.


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on removing an existing
         coating from a radiator and refinishing it by either
         repainting, rebronzing, or polychroming.

         1.   Bronzing is a decorative method of painting
              radiators using a mixture of bronzing liquid and
              bronzing powder to achieve a metallic surface
              appearance.

         2.   Polychroming is a decorative method of painting
              radiators that involves the use of two and three
              color paint schemes to highlight the ornament.

    B.   Safety Precautions:

         1.   PAINT BEING REMOVED MAY CONTAIN LEAD.  ALL WORKERS
              MUST WEAR PROTECTIVE CLOTHING (INCLUDING HAIR),
              GOGGLES, RUBBER GLOVES AND RESPIRATORS WITH HIGH
              EFFICIENCY PARTICULATE AIR FILTERS (HEPA).

         2.   No food or drink shall be allowed near any work
              station to prevent contamination from paint, paint
              chips, dust or chemical removers that contain lead
              and other toxic substances.

         3.   Protective clothing shall be removed at the end of
              each day and kept at the site to prevent workers
              from tracking dust and paint chips to other parts
              of the site or to their homes.

         4.   Wash hands and face often, especially before eating
              and at the end of the day.

         5.   All waste material shall be collected at the end of
              each work day and disposed of consistently with
              local environmental regulations.  It is considered
              Hazardous Waste.

    C.   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 before performing
         this procedure and should be followed, when applicable,
         along with recommendations from the Regional Historic
         Preservation Officer (RHPO).


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   American Brush Co.
         Wellesley Office Park
         60 Williams Street
         Wellesley, MA  02181
         617/235-5088
         (Radiator Brushes and Paints)

    B.   Benjamin Moore, Co.
         51 Chestnut Ridge Road
         Montvale, NJ  07645
         201/573-9600

    C.   Glidden Coatings & Resins
         Div. of SCM Corp.
         925 Euclid Avenue
         Cleveland, OH  44115
         216/344-8216

    D.   Johnson Paint Co., Inc.
         355 Newbury Street
         Boston, MA  02155
         617/536-4244
         (Paints and Bronzing Liquids and Powders)

    E.   3M Consumer Products Group
         Box 33053
         St. Paul, Minnesota  55133-3053

    F.   PPG Industries, Inc.
         1 Gateway Center
         Pittsburgh, PA  15222

    G.   The Sherwin Williams Co.
         101 Prospect Ave. N.W.
         Cleveland, OH  44101

    H.   Specialty Environmental Technologies, Inc.
         4520 Glenmeade Lane
         Auburn Hills, MI  48326

    I.   Wolf Paints and Wallpapers
         771 Ninth Avenue
         New York, NY  10019
         212/245-7777
         (Radiator Brushes and Paints)

2.02 MATERIALS

    A.   Commercial paint remover, such as "Citristrip"
         (Specialties Environmental Technologies, Inc.), "Safest
         Stripper" (3M), or approved equal.

    B.   Zinc-rich oil-based primer such as zinc chromate or red
         iron oxide-linseed oil paint:

         1.   Good for use on partially deteriorated surfaces.

         2.   Provides protection where moderately corrosive
              conditions exist.

         -OR-

         Modern alkyd paint:

         1.   Should only be applied to clean, noncorroded
              surfaces.  

         2.   Provides protection where there are only mildly
              corrosive conditions, and where normal humidity and
              condensation ranges exist, i.e., a residential or
              office environment.

         NOTE:  CONSULT THE PAINT MANUFACTURER FOR APPROPRIATE
         CHOICE FOR USE ON METAL.  

    C.   Oil-based paint:  Use a non-metallic flat paint.

         -OR-

         Metallic oil-based paint (ONLY IF MAXIMUM HEAT TRANSFER
         IS NOT AN IMPORTANT FACTOR)

         1.   Any oil-based top coat, made to be used with the
              primer, may be applied as the top coats.  

         2.   Use paint from the same manufacturer for both prime
              and top coats, and make sure they are made to work
              together.

    D.   Bronzing Supplies:

         1.   Bronzing powder (the pigment):  Available in a wide
              range of metallic tones.

         2.   Bronzing liquid (the vehicle):  Oil-based.

2.03 EQUIPMENT

    A.   Radiator Brushes (American Brush Co., Wolf Paints and
         Wallpapers), or approved equal:

         1.   One with long handle to reach between the radiator
              fins

         2.   One with an offset handle for reaching behind the
              radiator

         3.   1-1/2" camel's hair brush

         4.   A wide, flat, soft brush

         5.   Stiff wire brush

    B.   Goggles

    C.   Face mask

    D.   Drop cloths

    E.   Masking

    F.   Ball peen hammer


PART 3---EXECUTION

3.01 PREPARATION

    A.   Before recoating, determine what role the paint or
         coating is to provide.

         1.   If maximum heat transfer is important, use a non-
              metallic coating such as a flat, black paint (a
              flat finish surface radiates heat better than a
              shiny one).

              NOTE:  OIL PAINTS GENERALLY DO NOT REDUCE HEAT
              TRANSMISSION IN A RADIATOR AND ARE SUITABLE FOR USE
              WHEN MAXIMUM HEAT TRANSFER IS AN ISSUE.

              NOTE:  AVOID USING METAL BRONZE PAINTS OR ANY
              PAINTS CONTAINING METAL PARTICLES.  THESE TEND TO
              REDUCE HEAT TRANSMISSION IN A RADIATOR.

         2.   If aesthetics are important and potential heat loss
              is acceptable, bronzing may be a suitable
              alternative.

3.02 ERECTION, INSTALLATION, APPLICATION

    A.   Strip existing coating from the radiator.

         CAUTION:  PAINT MAY CONTAIN LEAD.  FOLLOW ALL SAFETY
         REGULATIONS REQUIRED BY STATE AND FEDERAL LAWS ON LEAD
         PAINT ABATEMENT AND DISPOSAL.

         1.   Mechanical Method:  This method is typically the
              most commonly used and the most successful.

              a.   Knock off loose paint and scale using a stiff
                   wire brush.  Special radiator brushes are also
                   available (see Part 2 above).

              b.   Tap the radiator repeatedly with a ball peen
                   hammer to loosen the paint bond on tougher
                   areas.

              c.   Vigorously brush the radiator again with a
                   stiff wire brush to remove remaining paint.  A
                   wire brush on a rotating drill may be used if
                   the worker is protected and working in an
                   isolated area.

         2.   Chemical Method:  This method is typically time-
              consuming and messy.

              a.   Apply a NON-methylene chloride paint stripper
                   using a stiff bristle brush.

              b.   Cover the stripper with strips of plastic wrap
                   to prevent the solvents in the stripper from
                   evaporating.

              c.   Allow stripper to remain on the surface for
                   length of time as recommended by manufacturer.

              d.   Remove plastic wrap and remove sludge with
                   small chisels and brushes.

              e.   Rinse the surface with mineral spirits and
                   allow to dry.

         3.   Heat Method:  This method is not very effective in
              removing coatings from a radiator.  Heat from the
              heat gun gets absorbed into the cast iron before it
              has time to soften the paint.

         4.   Remove the radiators and have them stripped off-
              site by immersion-tank stripping or sandblasting.

              NOTE:  REMOVAL AND REINSTALLATION OF A RADIATOR IS
              VERY DIFFICULT.  THIS METHOD SHOULD ONLY BE USED IF
              REMOVAL OF THE RADIATOR IS REQUIRED FOR OTHER
              PURPOSES.

              a.   Drain the hot water system and disconnect the
                   radiator.

              b.   Remove the radiator and send off-site for
                   stripping and recoating.

    B.   Refinish Radiator:

         1.   Painting:  

              CAUTION:  DO NOT USE WATER-BASED PAINTS ON CAST
              IRON.  THEY MAY CAUSE THE METAL TO RUST.

              1.   Prime paint the radiator using a brush for
                   complete even coverage.

              2.   Brush apply two top coats of the selected oil-
                   based paints.

         2.   Bronzing:

              a.   Prime paint the radiator using spray auto-body
                   paint.  Auto-body paint is appropriate for
                   several reasons:

                   1)   It can withstand radiator heat.

                   2)   It is sandable, enabling one to hide
                        small imperfections in the metal.

                   3)   It is available in light grey and other
                        colors suitable as a base for bronzing.

              b.   Sand the entire surface with fine-grit
                   sandpaper.

              c.   Brush sandpaper dust from the surface using a
                   stiff bristle brush.

              d.   Mix bronze metallic paint in a bucket.  Mix
                   1/2 lb. bronzing powder with 2 cups bronzing
                   liquid.  Add the powder to the liquid to
                   achieve a paint the consistency of cream.

                   NOTE:  1 QT. BRONZING LIQUID TYPICALLY COVERS
                   250-300 S.F.

              e.   Brush mixture onto the radiator carefully
                   using several soft bristle brushes as required
                   (see brushes under Part 2 above).

                   NOTE:  BE SURE TO USE SOFT BRISTLE BRUSHES.  A
                   STIFF BRUSH MAY INHIBIT ACHIEVING A SMOOTH
                   METALLIC FINISH WHEN APPLYING THE BRONZE
                   PAINT.  ALWAYS BRUSH IN THE SAME DIRECTION.

         3.   Polychroming:  Typically used on ornamental
              radiators for highlighting special ornamental
              portions.

              a.   Prime paint and sand the radiator (see Section
                   3.02 B. 2. a-c above).

              b.   Using brushes, paint the entire radiator the
                   color desired for the ornament and allow to
                   dry.

              c.   When dry, paint the entire radiator the color
                   desired for the background.

              d.   While the second coat of paint is still tacky,
                   wipe a clean cloth or sponge over the ornament
                   ONLY to expose the paint color below.

              e.   The ornament may also be hand painted if
                   desired.

                             END OF SECTION