With Ford’s 2015 F-150 aluminum body pickups hitting the market, collision repair shops are looking for ways to properly handle the messy and potentially explosive airborne aluminum dust caused by grinding or sanding. The aluminum dust that is created, it turns out, can create problems and hazards ranging from cross-contamination of metals that affect paint jobs to combustible dust fires and even explosions.
Cross-contamination occurs when aluminum dust in the air settles on steel panels or iron oxide dust settles on aluminum panels, prior to primer or paint. This contamination will result in poor adhesion and quality problems months and years after painting a panel. This can pose a real business risk to a collision repair shop that is forced to deal with warranty issues and customer come-backs.
Isolating aluminum repairs with curtains or dividers can help prevent cross contamination, but it does nothing to prevent the risk of fire or explosion. Aluminum dust poses a combustion hazard in high concentrations, and is particularly combustible, even explosive, when airborne and finely separated. If a typical vacuum containing dry aluminum dust within the unit were to draw in a grinding spark or even experience the spark from static electricity, it could ignite and cause a fire or explosion.
The solution, it turns out, centers on a piece of equipment called a wet mix air filtration system that is designed to vacuum up the dust at its source and prevent it from becoming airborne.
A wet mix air filtration system, also known as an immersion separator, essentially captures aluminum dust within the body shop at its source while using water to ensure potentially explosive aluminum dust particles do not become airborne within the unit itself.
Ford, for its part, is at the forefront of setting the guidelines and requirements for working with aluminum bodied vehicles. Ford’s 2015 F-150 Collision Repair program, created by Ford to assist dealers and independents, stipulates a dedicated aluminum wet mix air filtration system.
Vacuum extraction of aluminum dust, in fact, has been standard in aerospace for decades, as lightweight aluminum has long been used as a primary manufacturing material. Now similar technology is being used in the automotive industry to control aluminum dust.
One such system, for instance, by Clayton Associates, a Lakewood, N.J. based leader in source capture tools and vacuum sanding equipment, directs the air stream and aluminum dust through a series of air filtration baffles that bursts the air bubbles and thoroughly wets the dust before the air exits the vacuum.
The company also manufactures vacuums for aluminum dust ranging from air-powered portable dry units, up to single and multi-user immersion separators that use water to “wet” the dust out of the air stream. While Ford’s specific requirements call for an immersion separator, dry collection vacuum systems have been used in aerospace to capture aluminum dust at its source for over a decade.
“The transfer of safe, high efficiency, aluminum dust capture technology like Clayton’s from aerospace to auto body collision repair is going to make our industry safer, cleaner, and more efficient,” says Gary Gardella Jr., co-owner and production manager at County Line Auto Body in Howell, N.J., a high-production, Ford certified, collision repair shop, that repairs about 50-70 vehicles per week. Gardella adds that he is currently testing several of the vacuum and air-powered units around his shop.
In wet mix technology, one challenge is that a wet aluminum sludge remains at the bottom of the vacuum. This needs to be emptied on a daily basis as part of proper maintenance to ensure safe operation. While some units require the user to drain the fluid, then extract the remaining sludge with a squeegee, this method fails to fully remove the sludge caked on the sides of the unit. This allows a potentially dangerous build up of aluminum to accumulate.
Other units like Clayton’s immersion separator involve a gravity feed drain with a funnel-shaped bottom and water spray-down system inside. This enables a safer, full-system, flush out of aluminum sludge and facilitates daily maintenance.
The aluminum sludge, in turn, must be properly filtered to satisfy regulation before the discharge can be emptied into the public sewer system. Aluminum dust vacuum units like Clayton’s immersion separator are designed to filter out such aluminum residue as it exits the unit, so it can be safely discharged into public sewers.
Del Williams is a technical writer based in Torrance, California. For more info, call 732-363-2100; 800-248-8650 toll free; Fax 732-364-6084; email [email protected]; visit www.jclayton.com; or write to Clayton Associates, Inc., 1650 Oak St., Lakewood, NJ 08701, USA.
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