By Kimberly Koonce, Eastern Fleet Readiness Center
TIP CHERRY – Materials engineers at Fleet Readiness Center East faced a dilemma. Craftsmen must remove paint from an aircraft before they can service it, but exposure to harsh chemical stripping agents can damage the composite materials that make up the V-22 Osprey. Meanwhile, hand sanding methods are time consuming and physically demanding on the workers.
As a solution, engineers adopted the business practice of adding an intermediate coat to protect composite materials from chemical strippers while reducing the amount of hand sanding required to clean the aircraft. Recently, the team’s original thinking was rewarded when the first full chemical stripping of an Air Force CV-22 Osprey was a resounding success.
“We applied a chemical paint stripper and it attacked the gray topcoat,” said Chris Gladson, materials engineer for FRC East. “The stripper will attack the midcoat and remove most of it as well, but it will protect the primer and the substrate. This is his job.
Joey Fulcher, supervisor of the FRC East paint shop, said the chemical stripper removes up to 90% of the topcoat in a fraction of the time of manual sanding.
“After we masked (the plane), we applied the chemical stripper and let it sit for an hour,” Fulcher said. “The paint was literally falling off the plane. We rinsed the plane with hot water and steam, and called it a day.
Mr. Gladson said the payoff was long overdue; The Materials Engineering group began working on this problem in 2010. After years of engineering investigations both at Marine Corps Air Station Cherry Point and at Naval Air Systems Command Headquarters in Patuxent River, In. the Maryland team chose to adopt the mid-coat paint process, which had been used on commercial aircraft, but not in military aviation.
In 2016, all V-22 Ospreys painted at FRC East and other NAVAIR maintenance facilities began to receive a selectively removable mid-coat paint between the primer and finish coats. The intermediate layer forms a polymeric web which protects the primer layer and the composite surface from the chemical stripping agent.
As the Ospreys go through a planned maintenance cycle of approximately five years, the first aircraft painted with a mid-coat paint returned to FRC East for maintenance in September, during the first test of the mid-coat process within of the Ministry of Defense.
Successful chemical cleaning is good news for the artisans working on the FRC East paint line. Hand sanding an airplane the size of a V-22 Osprey is a long and arduous process. Depending on the age and hardness of the paint surface, sanding a V-22 can take up to a week for a team of eight to ten people to remove the top coat of paint. Supervisors said hand sanding protects the integrity of the composite surface, but negatively impacts workers.
“You have an air-supplied hood, gloves, everything is in place,” Mr. Fulcher said. “You have to come down and crawl under the belly of the plane, you’re on elevators under the wings, you’re standing sanding over your head. Everything that is involved weighs on people.
While hand sanding will always be part of the painting process, engineers at FRC East estimate that chemical stripping will cut sanding time by a third. Mr Fulcher said the paint shop workers are excited about the process change.
“Every time you tell them, no you don’t have to sand that much, it makes everyone happy,” he said.
FRC East executives said adapting the midcoat paint removal process to the V-22 platform shows how creative problem solving can benefit both FRC East employees and to the fleet units they serve.
“The adoption and implementation of the mid-layer stripping process for the V-22 Osprey is a victory for the aviation maintenance professionals of FRCE and the fleet units we serve,” said David W. Rose, Acting Director of the Maintenance, Repair and Overhaul Department at FRC East. “We can reduce some of the physical demands on our employees in cleaning, stripping and painting shops while reducing turnaround time by at least a day and a half. It’s just kindness all around.