July 21, 2021
Aircraft paint must not just look good. It must be able to stand up to the stressors of high ultraviolet levels during flight, along with frequent and significant temperature and humidity changes, which can promote corrosion.
So, what should aircraft operators consider when planning paint work to ensure a long-lasting, quality paint job? Also, as business aviation focuses more on sustainability, what new paint products or methods make aircraft painting more environmentally friendly than in the past?
Planning a Paint Job
Experts suggest that aircraft owners should prepare well in advance of a planned paint job. Ask the paint shop not just how long the job will take or what it will cost, but what processes will be used on your aircraft and what the company applying the paint is doing to employ greener products and technology.
George Bajo, sales manager of modifications at Duncan Aviation, says proper advance planning of paint work is especially important today, since the COVID-19 pandemic and resulting supply shortages have affected lead times significantly. Also, demand for new paint work is high, further increasing the backlog.
Aircraft owners can help ensure an efficient project timeline by choosing the design and colors well before their scheduled painting date. Bajo says common colors are often readily available, but less common colors might require a longer lead time. Operators also need to understand that custom paint work, including pearl and metallic colors, increases the overall time needed to do the job.
Bajo suggests that operators have other work done on the aircraft, such as interior or avionics updates, at the same time they plan to paint the airplane. That can minimize overall aircraft downtime. However, any aircraft inspections should be scheduled before the paint work is finished so the inspection process doesn’t risk damaging a new paint job.
Also, operators should adjust their flight schedules accordingly. A good paint job will take up to a month to complete. Use the downtime to send pilots to training, or to conduct company-wide safety events.
Waterborne or water-usable primers that are more environmentally friendly and have lower amounts of volatile organic compounds (VOCs) are now available. VOCs are emitted as gases from certain solids or liquids and include a variety of chemicals, some of which may cause adverse health effects.
PPG, a leading manufacturer of aircraft paint and supplies, is striving to conduct business in a more sustainable manner and to create more environmentally friendly products. “What is good for our community and ecosystem is also better for our customers,” said Vignesh Palanivel, PPG’s global product manager of aerospace coatings.
Palanivel said 35% of PPG’s sales in 2020 were from “sustainably advantaged” products and processes as the company works on greener technologies, including developing more chrome-free and low VOC products, as well as advancing electrodeposition techniques.
Electrodeposition technology, which has been used in the auto industry for years, saves time by delivering a cured, ready-to-use part that could potentially reduce up to 75% of part coating weight over conventionally spray-applied process, depending upon part complexity. Decreased weight translates into more efficient fuel burns and lower CO2 emissions from aircraft.
The ultimate goal is a painting process that does not rely on hexavalent chromium or chromates; in other words, a chrome-free paint process, from stripping to priming to color and topcoat. While “chrome-free” products often contain trace amounts of chromium or lead, the levels are low enough to be treated as common waste, not hazardous waste.
Upgrading Painting Facilities
Constant Aviation’s new Orlando, FL paint shop is working toward greener application of aircraft paint by modifying the facility it recently extended its lease on.
Sandy McPherson, Constant Aviation’s director of painting, explained the facility has been fitted with a three-stage filtration system to minimize the particulates that enter the environment. The filtration system is monitored, and alarms advise if emissions levels are exceeded. The company also runs water used in the paint process through its own water treatment facility before it goes on for further treatment by the city.
Duncan Aviation has invested in greener facilities as well. Bajo says the company’s Provo, Utah, paint complex, for example, releases no waste products into the water or into the city. All liquid discharge from the process is evaporated, with the minimal remaining solid waste disposed of by licensed handlers. All vapor and airborne discharges go through a regenerative thermal oxidizer, which burns off the VOCs so more than 99.7% of the air released is clean. The total discharge is reduced by 98%, compared to a conventional paint process.
Making It Last
Paint shops help ensure the longevity of a paint job by doing quality prep work and using reliable base coats, said McPherson. Nevertheless, operators must treat newly painted aircraft with some TLC to ensure the paint job lasts. Maintaining the paint properly, including possibly applying a polymer coating 30-60 days after the initial paint work is finished, is important.
So is periodic cleaning. Some polymer coatings are buffable, meaning a layer can be buffed off, a new layer applied, and the paint is returned to almost-new condition. And longer-lasting paint work means fewer paint jobs over the lifespan of the aircraft, minimizing the overall environmental impact of aircraft painting, which is good for the planet.