Applying Paste Wax Over "Incralac" Coated Bronze

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 applying a paste wax to outdoor bronze metal currently coated with Incralac or similar acrylic resin coating. The bronze may be either architectural components or sculpture.
  2. Paste wax helps to prolong the life of the coating. Discolorations in the bronze may be disguised by adding a pigment to the wax.
  3. Wax annually (if exposure is severe, semi-annually.)
  4. For general information on the characteristics, uses and problems associated with bronze, see 05010-03-S.



  1. Fisher Scientific Co.


NOTE: Chemical products are sometimes sold under a common name. This usually means that the substance is not as pure as the same chemical sold under its chemical name. The grade of purity of common name substances, however, is usually adequate for stain removal work, and these products should be purchased when available, as they tend to be less expensive. Common names are indicated below by an asterisk (*).

  1. Hog bristle stencil brushes, 2-inch diameter, 1-3/4 inch bristle length, such as No. 996 in Industrial Soap Catalog
  2. Clear white paste wax, such as Trewax clear, Butcher's bowling alley wax, or approved equal. Trewax clear and Butcher's bowling alley wax are mixtures of microcrystalline wax, carnauba and a mild solvent, in paste form.

  3. Powdered pigment, burnt umber and black
  4. Mineral spirits:
    1. A petroleum distillate that is used especially as a paint or varnish thinner.
    2. Other chemical or common names include Benzine* (not Benzene); Naphtha*; Petroleum spirits*; Solvent naphtha*.
    3. Potential Hazards: TOXIC AND FLAMMABLE.
    4. Safety Precautions:
      2. ALWAYS wear rubber gloves when handling mineral spirits.
      3. If any chemical is splashed onto the skin, wash immediately with soap and water.
    5. Available from construction specialties distributor, hardware store, paint store, or printer's supply distributor. -OR- Turpentine
  5. Gloves, disposable polyethylene or neoprene rubber (may be ordered from Fisher Scientific Co.). Disposable surgical gloves may also be used, but they are vulnerable to organic solvents.
  6. Clean, potable water


  1. Small quart-size, galvanized metal pail or other clean container
  2. Spoon, and/or palette knife or spatula
  3. Rags, soft, clean and lint-free



  1. Place approximately six ounces of paste wax into the pail. Add about an equal amount of thinner (mineral spirits or turpentine). If pigment is necessary, add either umber, black or an appropriate mixture of the two to give sufficient color to the mix.
  2. Mix and blend well using the spatula and the brush, adding more thinner if necessary to produce a thick creamy consistency (about the consistency of a thick soup). As the thinner evaporates, add more as necessary to maintain a workable mix.
  3. Apply the wax mixture thinly using the ends of the brush hairs to work the mixture into the depths of forms and textures. To apply the wax, use a perpendicular striking motion with the brush rather than a stroking motion. Be careful not to scratch the coating with the metal ferrule of the brush.
  4. When the solvent has evaporated, rub and polish the surface with a clean cloth. A thin, polished coating of wax will remain. If pigmented wax is used it can be selectively removed according to the requirements of the bronze.