As Good As New
Todays high-quality painted and anodized architectural finishes are extremely durable, but even the best finish needs a little tender loving care. Even with the most careful treatment of windows, curtainwall or storefront during installation and daily use, occasional damage will occur. This article discusses the recommended care of painted or anodized finishes on architectural metal and looks at three levels of concern: care and cleaning, minor repairs and complex refinishing.
Care and Cleaning of Painted Material
Todays factory-applied heat cured painted finishes are durable and colorfast. The Kynar®- and Hylar®-based products that meet the AAMA 2605 specification and/or ASCA 96 (with trade names such as Duranar by PPG, Fluropon by Valspar or Trinar by Akzo-Nobel) are warranted to retain their color and gloss level for many years. To assure that they retain their original beauty, these highly-durable finishes should be cleaned occasionally. When selecting a cleaning solution, use mild soap solutions that are safe for use with your bare hands such as products used to wash a car. Avoid the use of strong acid or alkali cleaners as they may damage the finish.
The mild soap solution should be applied with a soft cloth, sponge or soft brush once heavy soil, grease or sealant is removed. Rinse the surface thoroughly with clean water and dry with a soft cloth.
Solvents no stronger than mineral spirits or denatured alcohol may be used to remove grease, sealants or other materials. Never mix cleaners or cleaners and solvents as the resultant mixture can cause harmful or even dangerous results. Do not use abrasive cleaners or materials such as steel wool or abrasive brushes, which can also harm the surface.
In coastal areas where the finish is exposed to salt spray or in areas containing heavy industrial pollutants, the cleaning should take place on a regular basis. Cleaning the painted finish can be scheduled as a part of the regu-
lar maintenance program for glass
Cleaning Anodized Material
Anodized material has a very hard surface that is colorfast and mar-resistant. The Class I clear or color anodized finishes applied by a computer-automated, high-quality commercial anodizer specializing in
architectural finishing will provide consistent color and long product life in a variety of applications.
Much like painted surfaces, an anodized finish should be cleaned using mild soap solutions to retain its original beauty. Products that are safe for use with bare hands (including most commercial cleaning products) can be used safely. The cleaning solution should be applied with a soft cloth, sponge or brush. Avoid the use of strong acid or alkali cleaners.
Severely soiled anodized surfaces can be cleaned a bit more aggressively than painted surfaces. For example, a mild abrasive pad such as Scotch-Brite® can remove slight scuff marks and rub marks on an anodized surface. Use the pad to remove the mark, then clean the surface using the mild soap solution, rinse the surface thoroughly with clean water and dry with a soft cloth.
Like with painted material, anodized material in coastal areas
or areas containing heavy industrial pollutants, should be cleaned as part of a regular maintenance program.
It is almost a given that some damage will occur and touch-up work will be required during or after installation. But the good news is that both painted and anodized surface damage can be repaired easily if the damage is slightsuch as a scratch or rub mark. Minor painted surface damage can be sanded with excellent results prior to touch-up painting. For scratches or gouges, use a relatively course grit paper to remove the damage. Then use progressively finer paper to remove the sanding marks, finishing with a 180 to 220 grit paper.
Sanding anodized material that is going to be touched up is not recommended. The anodized surface is aluminum oxide, which generally is harder than the sandpaper. Some rub marks on an anodized surface can be removed with a mild abrasive pad such as the Scotch-Brite® pad prior to touch-up painting.
Custom finishers usually supply a limited amount of touch-up paint with the project material. Touch-up paint is supplied in small aerosols or bottles with a built-in brush for easy application. It is to be applied very sparingly. It is intended to cover small blemishes or to touch-up exposed cut ends on fabricated parts. It is not intended for use on large areas of more than a few square inches. The color will match the factory applied painted or anodized finish closely, however the finish is not as hard, nor performance the same, as the baked-on finishes. After cleaning the area to be touched up, wipe the area with denatured alcohol to remove any moisture or cleaning residue and apply the touch-up per the finishers instructions. Use caution, as excessive use of touch-up paint may void the original finishers warranty.
Repairing the Finish on Curtainwall, Windows
Occasionally, a window, curtainwall or storefront frame will become damaged or discolored beyond the point where simple field touch-up will correct the problem. Damage can result from a variety of sources. These include final cleaning of the building facade without proper protection of the aluminum surfaces, environmental impact from the seacoast or corrosive atmosphere exposure, long term neglect, or selection of the wrong finish at the time the material was finished and fabricated.
Correcting Severe Damage (Calling in the Pros)
The large, full-service finishing companies such as ours employ field service professionals who are trained in the proper preparation and application of field applied architectural finishes. Coatings that meet AAMA 2605 specifications and which can be applied in the field are available to these professionals. The highly specialized coatings, known as ADS Systems, can be tinted to match nearly any existing or desired painted or anodized finish color. Special cleaning and pre-treatment procedures are critical to achieve the desired long-term results. The paint also must be formulated to match the characteristics of the existing finish closely, particularly if only a portion of the existing surfaces will be refinished. Specifically, the new coating should be formulated to have approximately the same fade or chalk characteristics as any exposed original finish, so the entire project will have a uniform appearance for many years.
Contracting for the services of a professional who specializes in the refinishing of architectural metals will assure that the work is completed using the correct methods and proper materials, assuring satisfaction with the long-term results guaranteed.
Completion of a field repair can be handled in several ways. In general it will begin with an initial contact with the field service professional to describe the problem. The scope of a field-refinishing project varies greatly, involving anything from a single door or window to a building elevation or an entire building. Usually, the field service professional will recommend a site visit to examine the problem for all but the simplest repairs. Following the site visit, the field service professional will prepare a quotation for the work to be completed and also a sample color chip for approval. At times preparation of an on-site sample for approval (a single door, panel or window) will be recommended. Following acceptance of the quotation and samples and preparation of a contract for the work to be completed, the work will begin. Field repairs generally can be performed at temperatures above 50 degrees Fahrenheit. The field service professional will handle all of the details such as permits, sidewalk protection and barricades.