Volume 38, Issue 5, May 2003


Coming Clean
Steps For Cleaning Architectural Aluminum
by Eliza McClatchey Evans

As finishers of architectural aluminum for more than 55 years, we get questions all the time about how to maintain the product during and after installation. Aluminum use is increasing in the construction industry, and one reason is the integrity of the finishes available. Many of these coatings, whether anodic or organic, are factory applied and can not be re-applied easily in the field. Therefore, maintenance of the existing coating is very important.

Maintenance Concerns
Many participants in a building project are concerned with the maintenance of the architectural aluminum. Building owners are concerned with the occupancy of the building; if the building looks dirty and run-down, the owner’s investment is in danger. Building managers usually are responsible for upkeep. Contractors may have agreed in writing to provide a product free from concrete and mortar runoff, as well as provide maintenance 

The maintenance schedule of the aluminum finishes varies depending on the type of finish, the climate in the geographic location and the location of the material on the building itself. Anodized aluminum is corrosion-resistant, but if it is neglected or subjected to smoggy or salty conditions it can appear dull or dirty. 

Climate and environmental conditions will determine the composition of the deposited material, whether it is water-soluble and even how fast it dries. It is preferable to perform cleaning activities on an overcast day when the sun will not dry the cleaning chemicals quickly, although mortar and cement should be removed as quickly as possible. For light surface soil, the first step is to use water at a moderate temperature and pressure for both anodic and organic coatings. If dirt remains after the surface has dried, sponging or brushing with detergent may be necessary. Address any detergent run-down into caulked areas or areas where additional, vulnerable materials may be installed. Do not allow the cleaner to puddle, and clean the building thoroughly. 

Additional Tips
For heavier soil that is not responsive to water and light detergent, anodic coatings may be cleaned with a more abrasive cleaning pad or pumice powder. Solvents may be used if necessary, but it is important to test a small area first. Painted finishes must be treated differently than anodized finishes, since abrasive cleaning may damage the finish. During installation it is common for sealant or caulk to run over on to the metal. In these, mineral spirits may be used, but nothing stronger as it may actually soften the organic coating. A solution of muriatic acid that is under 10 percent may help with concrete stains, in addition to scrubbing with a non-abrasive brush. Use solvents sparingly, always avoid extremely aggressive acid and alkaline cleaners and rinse with water.

Know Your Finishes
One of the most important things to remember is that the aluminum finish must first be identified correctly. For example, if an anodic finish is mistaken for a painted finish, cleaning with an abrasive substance that is intended for anodic coatings may scratch the painted coating severely. Testing any cleaning method on a small surface is always a good idea. If there are questions about how to clean the finished product, contact the manufacturer.

Finally, the American Architectural Manufacturers Association (AAMA) has written a specification on the cleaning and maintenance of architectural aluminum coatings, AAMA 609 & 610-02. It is a copyrighted publication and is available for sale on the AAMA website at http://www.aamanet.org/pubstore/ProductResults.asp. It is easy to download, may be mailed or is available on a CD. This publication costs $8, but the information may prove invaluable. 

Eliza McClatchey Evans, CSI, is the fabrication project manager for Southern Aluminum Finishing in Atlanta


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