Cleaning and Repainting Exterior Aluminum

Technical Procedures Disclaimer

Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.


We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.



  1. This procedure includes guidance on cleaning polish- finished, bare satin-finished, and non-finished exterior aluminum, and repainting.
  2. Read "General Project Guidelines" along with this specification. 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). The 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)


  1. Submit all cleaning products to the Contracting Officer for approval prior to use on the job.
  2. Test cleaning areas will be approved by the Contracting Officer before any large scale cleaning is begun.
  3. Standards: Architectural Aluminum Metals Association Guidelines for the Cleaning of Aluminum, including specification 609.1 (available from the AAMA, 35 East Wacker Drive, Chicago IL 60601).
  4. Follow paint manufacturer's printed instructions for surface preparation, application and clean up.


  1. All painting shall be executed at a temperature between 50 F and 85 F at a relative humidity below 60%.
  2. If mild acid is used, protect adjacent surfaces from run-off.


  1. Projects involving use of phosphoric acid cleaners are subject to employee safety and environmental protection laws. Specified products may not be permitted or appropriate for all locations. Products containing chemicals known to present health or environmental hazards should be used only as a last resort, where permissible, in accordance with manufacturer's directions for application, ventilation, and disposal. Explore potentially affective, milder products before proceeding to stronger alternatives.



  1. ProSoCo, Inc.

Lawrence, KS


  1. Sherwin-Williams

Cleveland, OH


  1. ITW Devcon, Inc.

Danvers, MA


  1. W. M. Barr & Co.

Memphis, TN



  1. Cleaners:
    1. Mild soap, such as "Ivory Liquid" (Procter & Gamble Co.) or approved equal.
    2. Phosphoric acid cleaner with water, such as "Klean Strip Phosphoric Prep & Etch" (W. M. Barr & Co.), or approved equal.
  2. Scrub-brushes shall be natural (non-metallic), bristle only.
  3. Paint:
    1. Primer: Alkyd-base, such as "Kem Kronik Universal Primer" (Sherwin-Williams), or approved equal.
    2. Finish Coats (2): Alkyd-based, such as "Industrial Enamel" (Sherwin-Williams), or approved equal.
  4. Metal Filler: Two-part epoxy metal filler, putty-grade, such as "Plastic Steel Putty (A)" (ITW Devcon, Inc.), or approved equal.



  1. Protection: Prior to beginning work, mask and protect all surfaces which would be altered or damaged by the cleaning operation.
  2. Surface Preparation: 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 which are to be repainted have been cleaned, made smooth, and before any paint is applied.


  1. Cleaning Aluminum:
    1. Wash all aluminum surfaces with mild detergent such as "Ivory Liquid" and clean water using a damp sponge, soft cloth or, if necessary, a natural bristle brush and light pressure. Wipe dry with a clean cloth.
    2. Should stronger cleaning methods be required, a dilute phosphoric acid cleaner, such as "Klean Strip Phosphoric Prep & Etch" (W. M. Barr & Company) can be used, following the manufacturer's written instructions carefully.
  2. Painting Aluminum:
    1. Remove all paint, rust and scale from all steel surfaces, especially undersides and hidden locations, by mechanical and manual methods as necessary down to bright metal removing all traces of rust and scale.
    2. Replace or repair any badly deteriorated pieces of metal work to match the original in size, shape and location.
    3. Clean the bare metal of all oily or greasy residue with a degreaser, such as trichlorethylene available commercially in standard metal degreasers.
    4. Fill all small holes, depressions and cracks with metal filler following the manufacturer's written directions. Finish all filled areas by sanding flush after curing time has elapsed.
    5. Prime all metal within two hours of cleaning down to bare metal using color obviously different from the finish color.
    6. Use a brush to apply two finish coats of paint.