Radomes, tail cones, and other fiberglass or composite components on E-3, KC-135, and B-52 aircraft are coated with polyurethane rain erosion resistant coatings to protect them from the effects of rain erosion in flight. Oklahoma City Air Logistics Complex (OC-ALC) production workers must remove the coatings during depot overhaul to allow for inspection and repair.
Recent changes in requirements have made the use of the traditional paint remover obsolete. To avoid production impacts, OC-ALC production engineers requested assistance from the Air Force Research Laboratory’s Energy and Environment Team.
The E2 Program executes technology engineering, development, and demonstration of environmentally preferable alternative materials and processes to meet user requirements, progress solutions through Technology Readiness Levels, and highlight technology transition activities for Air Force enterprise use.
The E2 program initiated a project to identify, test, demonstrate, and transition suitable alternatives for removing coatings from composite components of the E-3, KC-135, and B-52 aircraft.
The team approached the research problem by:
- baselining the current depaint process
- developing a test plan to evaluate alternatives
- identifying suitable drop-in replacement alternatives
- conducting lab-scale performance and materials compatibility testing
- conducting a full-scale field demonstration
- supporting technology transition activities
Six potential alternative strippers, all benzyl alcohol based, underwent laboratory testing to evaluate effectiveness and effects on the composite material substrates.
Following successful laboratory testing, the team selected four alternatives for field demonstration to verify performance in the depot environment. Side-by-side comparison verified that all four alternatives performed satisfactorily and were considered comparable to the previously used material.
As a result, depot requirements were revised to include all four alternative strippers.