20-Dec-2021 Source: FRCE
Materials engineers at Fleet Readiness Center East (FRCE) faced a dilemma. Artisans must remove paint from an aircraft before it can be serviced, 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 for workers.
As a solution, engineers adopted the commercial practice of adding a midcoat layer to protect the composite materials from chemical paint strippers while reducing the amount of hand sanding required to clean the aircraft. Recently, the team’s out-of-the-box thinking was rewarded when the first full chemical stripping of an Air Force CV-22 Osprey met with resounding success.
“We applied chemical paint stripper, and it attacked the gray topcoat,” said Chris Gladson, FRCE materials engineer. “The stripper will attack the midcoat and remove most of it as well, but it keeps the primer and the substrate safe. That’s its job.”
Joey Fulcher, FRCE paint shop supervisor, said the chemical stripper removed as much as 90% of the topcoat in a fraction of the time of hand sanding.
“Once we got (the aircraft) masked, we applied the chemical paint stripper and let it sit for an hour,” continued Fulcher. “Paint was literally falling off the aircraft. We rinsed the aircraft with hot water and steam, and we called it a day.”
Gladson said the payoff has been a long time coming; the materials engineering group began work on this problem in 2010. After years of engineering investigations at both Marine Corps Air Station Cherry Point and at Naval Air Systems Command (NAVAIR) Headquarters in Patuxent River, Maryland, the team elected to adopt the midcoat painting process, which had been used on commercial aircraft, but not in military aviation.
In 2016, all V-22 Ospreys painted at FRCE and other NAVAIR maintenance facilities began receiving a selectively strippable midcoat paint layer between the primer and topcoat layers. The midcoat forms a polymer web that protects the primer layer and the composite surface from the chemical stripping agent. Because Ospreys are on a roughly five-year cycle of planned maintenance, the first aircraft painted with a midcoat paint layer arrived back at FRCE for maintenance in September, in the first test of the midcoat process within the Department of Defense.
The successful chemical cleaning is good news for the artisans who work on the paint line at FRCE. Hand sanding an aircraft the size of a V-22 Osprey is an arduous, time-consuming process. Depending on the age and hardness of the paint surface, sanding a V-22 could take a team of eight to 10 people up to a week to remove the top coat of paint. Supervisors said hand sanding protects the integrity of the composite surface, but it takes a toll on the workers.
“You have a supplied air respirator hood on, suited up with gloves, everything on,” said Fulcher. “You’ve got to get down and crawl under the belly of the plane, you’re on lifts under the wings, you’re standing up sanding over your head. Everything involved, it weighs on people.”
While hand sanding will still be part of the painting process, FRCE engineers estimate chemical stripping will cut sanding time by as much as a third. Fulcher said paint shop employees are enthusiastic about the process change.
“Anytime you tell them, no, you don’t have to sand quite as much, it makes everyone happy,” said Fulcher.
FRCE leaders said adapting the midcoat paint removal process to the V-22 platform shows how creative problem solving can benefit both FRCE employees and the fleet units they serve.
“Adopting and implementing the midcoat paint removal process for the V-22 Osprey is a win for FRCE aviation maintenance professionals and the fleet units we serve,” said David W. Rose, FRCE Maintenance, Repair and Overhaul Production Department acting director. “We can reduce some of the physical demands for our employees in the clean, strip and paint shops while we reduce the turnaround time by at least a day and a half. It’s just goodness all the way around.”
FRCE is North Carolina’s largest maintenance, repair, overhaul and technical services provider, with more than 4,000 civilian, military and contract workers. Its annual revenue exceeds $1 billion. The depot provides service to the fleet, while functioning as an integral part of the greater U.S. Navy; Naval Air Systems Command; and Commander, Fleet Readiness Centers.