Stripping And Repainting Exterior Galvanized Metal Windows

Procedure code:
National Capitol Region Specifications - Icc Building
Doors and Windows
Metal Windows
Last Modified:




    A.   This procedure includes guidance on removing paint build-
         up and repainting of all exterior galvanized metal
         windows to return them to operable condition.  It also
         includes caulking all joints between metal elements and
         masonry where required.

    B.   Safety Precautions: All precautions shall be taken to
         prevent the possibility of fire in storage space and
         areas being painted.

         1.   Provide adequate ventilation for removal of toxic

         2.   Provide at least one 2B fire extinguisher for each
              200 square feet of area occupied for paint storage
              and mixing.

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


    A.   Standards: National Association of Corrosion Engineers,
         5.1.3 NACE No. 3 Commercial Blast Cleaned Surface Finish
         in "Visual Standards for Surfaces of New Steel Ariblast
         Cleaned and Sand Abrasive."


    A.   Packing and Shipping: Deliver materials to the site in
         the manufacturer's original containers with labels
         showing manufacturer, contents and color. Delivered
         material shall be identical to accepted literature and

    B.   Storage and Protection: Store all materials in a single
         ventilated space. Storage space shall be kept neat and
         clean. Used rags, waste, and empty containers must be
         removed from the site at the end of each work day.


    A.   Environmental Requirements:

         1.   The temperature of the surface to be painted and of
              the air in contact therewith shall be maintained at
              a minimum of 50 F and maximum of 95 F.

         2.   No painting shall be done when relative humidity
              exceeds 85%.

         3.   Surfaces to be painted shall be protected from dust
              and dirt during painting and finishing.



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

    B.   Devcon Corporation
         30 Endicott Street
         Danvers, MA  01923


    A.   Paint for Exterior Steel:

         1.   Primer: One coat of zinc dust-zinc oxide primer
              such as "Galvanized Iron Primer," (Sherwin
              Williams), or approved equal;  minimum 2 mil.
              D.F.T. (Dry Film Thickness) total.

         2.   Finish Coats (2): Alkyd gloss such as "Matalastic
              II Enamel," (Sherwin Williams), or approved equal;
              minimum 4 mil. D.F.T. (Dry Film Thickness) total
              for both coats.

    B.   Colors:

         1.   Primer: Make each coat clearly different in color.

         2.   Base and Finish: Alkyd resin semi-gloss: Benjamin
              Moore or Sherwin Williams; make colors clearly
              different from each other and primer.

         3.   Dry Film Thickness:  Apply materials at not less
              than manufacturer's recommended spreading rate, to
              establish a total dry film thickness as indicated
              for each coat.

              a.   Primer: 2 mils.

              b.   Base and Finish Coats: 2 mils each.

    C.   Dry Grit Blasting: Fine grit No. 2-3 at 80-100 psi.

    D.   Backer Rod: Polyethylene compressible rod 50% larger in
         diameter than joint.

    E.   Sealant

         1.   Multi-part, non-sag urethane sealant in conformance
              with ASTM C290, Type M, Grade NS, Class 25 light
              buff to match color of window paint.

         2.   Joint primer recommended by the sealant
              manufacturer for specific applications and

    F.   Fillers: Two-part epoxy metal filler, putty grade such as
         "Plastic Steel A" (Devcon Corporation), or approved


    A.   Wire Brush: Non-ferrous metal brush, such as brass.



    A.   Protection: Enclose dry grit blasting work areas with
         temporary scaffolding or framework sufficient to support
         tarpaulin enclosure to prevent escape of abrasive. Shield
         adjacent masonry and glass with a temporary covering of
         cardboard or fiberboard held in place with heavy-duty
         strapping tape or wood bracing.

    B.   Surface Preparation:  

         1.   Determine that surfaces to which paint is to be
              applied are even, smooth, sound, clean, dry and
              free from defects affecting proper application.
              Contact the Contracting Officer after surfaces to
              be repainted have been cleaned and made smooth and
              before any paint is applied.

         2.   Remove all paint, rust and scale from all steel
              surfaces, especially undersides and hidden
              locations by mechanical and manual methods as
              necessary. Do not remove or damage any of the
              galvanized surface. Stop abrasive blasting as soon
              as foreign matter and paint has been removed. The
              sash are to be restored to full operation.

         3.   Paint removal may be done by dry grit blasting,
              scraping or sanding.

         4.   Remove all window air conditioning units from

         5.   Remove all sealant between metal window frames and

         6.   Clean the bare metal of all oily or greasy residue
              with a degreaser such as trichlorethylene available
              commercially in standard metal degreasers.

         7.   Fill all small holes, depressions and cracks with
              metal filler following manufacturer's written
              directions. Finish all filled areas by sanding
              flush, after curing time has elapsed. Prime all
              metal within two hours of cleaning down to bare
              metal using a color obviously different from the
              finish color.


    A.   Apply paint in accordance with manufacturer's printed

    B.   Apply paint evenly and smoothly, free of runs, drips,
         sags, crawling, brush marks, holidays and clogging or
         angles. All paint coatings shall be brush or roller
         applied as appropriate to surface and finish.

    C.   Apply successive coats only when preceding coats are
         thoroughly dry and hard. Sand between coats to produce
         even and smooth surfaces.

    D.   Apply additional coats when undercoats, stains, or other
         conditions show through final coat of paint, until pain
         film is of uniform finish, color and appearance. Ensure
         that corners, edges, crevices and exposed fasteners
         receive a dry film thickness equal to that of flat

    E.   Meeting lines between colors shall be straight and
         sharply defined with no blending, running or gaps.

    F.   Adjacent materials shall be fully protected by drop
         cloths or other suitable coverings. Paint drips,
         splatters, etc., shall be removed immediately.

    G.   Each coat of paint is to be slightly darker than the
         preceding coat with the final coat exactly matching the
         accepted samples.

                         END OF SECTION
Last Reviewed 2012-02-24