Volume 37, Issue 6, June 2002
The Finishing Touch
Cleaning and Maintaining Fluoropolymer-Coated Surfaces
by Steve Green
Inertia is one of the most beneficial characteristics of today’s Valspar 70-percent fluoropolymer systems. That is, the molecules on the surface of the coating are bound together so tightly that they don’t react with anything. The slick surface that results from such a coating is resistant to environmental elements such as air pollution, acid rain and general airborne dirt. Think of these coatings as the Teflon® of the architectural-aluminum world.
However, once the contract glazier has completed an installation, it may be necessary to clean or remove deposits from the finish of architectural aluminum. Adding the finishing touch to a quality installation may be that extra service much appreciated by general contractors.
There are a variety of methods for removal of surface deposits, but two precautions must be kept in mind regardless of the cleaning method used. Do not use wire brushes, abrasives or similar cleaning tools or substances that mechanically abrade the coating surface, and always test tools and cleaning agents in an inconspicuous area before using them on a large scale.
Solvents and Other Cleaning Methods
One of the simplest methods of cleaning a fluoropolymer surface is by using a 5-percent solution of any common commercial or industrial detergent in water. A cloth or soft bristle brush should be used for application, and the washing should be followed by a thorough rinse with clear water.
Solvents best address serious cleaning problems, but also present some handling challenges. Most organic solvents are flammable and/or toxic. They must be kept away from open flames, sparks and electrical motors. Organic solvents must also be applied in areas with adequate ventilation and users should wear protective goggles and clothing.
Alcohol is one solvent that may be used to remove non-water soluble deposits such as tar, grease, oil and paint from fluoropolymer surfaces. Denatured alcohol, isopropyl alcohol and methanol will have no permanent effect on the finished surfaces of architectural aluminum. Methanol is toxic, however, so handling precautions must be taken when using this solvent.
Petroleum solvents and turpentine are also choices that have no permanent effect on fluoropolymer surfaces. These include VM&P naphtha, mineral spirits, kerosene and wood or gum spirits.
Aromatic and chlorinated solvents should be used with caution on fluoropolymer surfaces. Chemicals such as Xylol, Toluol, Perchlorethylene and Trichlorethylene may be applied to a finish for a maximum of five minutes. It is also a good idea to test these solvents on an inconspicuous part of the surface before applying to larger areas. Since both Perchlorethylene and Trichlorethylene are toxic, they should always be used with care.
Ketones, esters, lacquer thinner and paint remover should be used cautiously on any fluoropolymer surface. Methyl-ethyl ketone (MEK) and Methyl-isobutyl ketone (MIBK) are common examples of this class of solvent. Acetone is also an example of this class of solvent, but it should never be used on fluoropolymer surfaces.
Ketones, esters, lacquer thinner and paint remover should be tested on the surface to be cleaned before application, and the amount of contact time between surface and solvent should be limited. Some paint removers may damage fluoropolymer surfaces, so use extreme care if you choose this method of cleaning your architectural aluminum.
There are many chemical solutions to finish-cleaning problems. Laundry bleach, hydrochloric (muriatic) acid, oxalic acid and acetic acid (vinegar) are all options. Muriatic acid, diluted with ten volumes of water, may be effective in removing rust stains from fluoropolymer surfaces. It is important, however, to limit contact time to five minutes. Acid solutions are corrosive and toxic, so all surfaces should be flushed with copious amounts of water after using these chemicals.
There is nothing more frustrating to a contractor than to leave a work site and return the next morning to find that a thoughtless person has scribbled graffiti on a new installation. Graffiti presents an especially vexing problem because so many different agents can be used. Aerosol paint is one of the most common media for creating graffiti. It is best to first try less active solvents such as the alcohols, petroleum solvents and turpentine and aromatic and chlorinated solvents. If these do not work, move on to the ketones, esters, lacquer thinners and paint removers. If none of these are satisfactory, it may be necessary to resort to touch-up, repainting or replacement, depending on the extent of the damage.
Presenting a general contractor with a sparkling clean installation is one little extra a contract glazier can offer the project team. Windows should shine, and so should the architectural aluminum. Take a few moments and a bit of planning to add that finishing touch.
Steve Green is the director of sales and marketing for Tubelite Inc. in Reed City, Mich.
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