Selectively strippable paint reduces aircraft downtime
British Airways is the recipient of the 500th new aircraft to be painted with a selectively strippable exterior coating that allows planes to be repainted up to 20 per cent faster and with fewer corrosion risks.
The Desothane coating system, from PPG Aerospace, allows the topcoat and intermediate layer to be removed for repainting without affecting the anti-corrosion primer underneath. As well as saving time, this maintains the aircraft's corrosion protection and avoids the need for harsh and toxic chemical strippers, said PPG's European coatings market manager, Richard Hargreaves.
“Airline maintenance operations are seeing their aircraft strip-and-repaint cycle shortened by up to two days, or by one-fifth, compared with a traditional cycle that can be up to 10 days,” he said, adding that around 50 of BA's fleet has now gone through a successful depaint/repaint cycle with Desothane.
“It is fitting that we reached this milestone with British Airways because it has specified the PPG selectively strippable system on close to 100 aircraft in its fleet. This is the largest fleet of selectively strippable aircraft in the world, and British Airways was also instrumental in the system’s development,” he noted.
The Desothane selectively strippable system consists of a chromate-free high-solids epoxy primer, a chromate-free intermediate coating, and a high-solids polyurethane topcoat. During selective stripping, a mild paint remover selectively removes the intermediate coat and topcoat, leaving the primer intact. The primer is then thoroughly cleaned, and the intermediate coating and topcoat are reapplied.
In addition to assisting the depaint/repaint process, the combination of intermediate coating and topcoat improves rivet paint adhesion and reduces paint film crazing, Hargreaves said. He added that the PPG system can also be applied over several of the structural primers used by airframe manufacturers to protect aluminium and advanced composite substrates.