By Joel Hall
For many years, Delta and other airlines used dangerous processes involving acids and other chemicals to paint airplanes.
Corrosive acids were used to clean the plane of debris before Alodine -- an adhesive agent which is both toxic and mutagenic -- was sprayed in order to make paint cling to a plane's smooth, aluminum surface.
PreKote, a biodegradable surface pretreatment, which Delta Air Lines adopted in its painting process last year, has eliminated the need for acid and Alodine altogether, saving the company time and money.
Last month, the U.S. Environmental Protection Agency's Design for the Environment Program recognized Delta for it's use of the environmentally friendly product on its aircraft.
"We evaluated it last August, so it's been about a year since we've been using PreKote," said Russ Ragsdale, principal engineer for enabling technologies at Delta. "It provides a better surface for the paint to adhere to," than Alodine. "It's a very easy process to apply. It takes less time for us to apply it than with those traditional methods."
Ragsdale said in the traditional process of painting planes, acid is applied to the metal to clean away embedded contaminants which may inhibit paint from sticking. However, the acid is corrosive and can eat away at the plane unless masking materials are used to cover the plane's vital parts.
"The PreKote doesn't damage those areas, so we don't need the masking materials altogether," said Ragsdale. He said that, per aircraft, between $3,000 and $4,000 has been saved on labor and materials alone by using PreKote.
PreKote is also safer for the people who paint the planes, because, unlike Alodine, it does not contain chromates, which are carcinogenic.
In addition to being non-toxic, PreKote is also non-corrosive, non-flammable, odor free, reduces water use and the need for waste-water treatment. It also does not require additional HAZMAT shipping charges to transport.
Tony Stephens, a lead shift supervisor for the Delta Technical Operations Center, where the planes are serviced, said PreKote "knocks a shift off the whole process."
"It's quicker because it replaces two processes, so the down time on the planes is not as much as it was before," said Stephens.
Ragsdale predicted the product will save Delta about $1 million a year.
"The biggest effect on the economics is that we can get the aircraft back into the air a day earlier than we used to," said Ragsdale. "That's a pretty significant difference, given one process change."