The global economy and environmental concerns are changing the aircraft painting business as more MROs seek coatings with fewer hazardous materials and greater efficiency.

“To reduce environmental and health risks, our customers are asking for primers and undercoats that are without chromates,” says J. Marc Taylor, director of sales for Sherwin-Williams Aerospace. “But they want chromate-free products to perform as well as those containing chromates, since it’s the undercoat that protects the metal from corrosion damage. We are developing new undercoating technologies that don’t use chromates and are having them approved at the [airframe] OEM level.”

Government authorities in particular are the driving force behind the demand for chromate-free primers, according to Frits Widdershoven, sales manager for Aviation Cosmetics, a narrowbody aircraft painting specialist in Holland. “The chromate-free primers will be the major trend in the aircraft painting business. But, the problem is that right now, the manufacturers of existing primers—without chromates—can’t guarantee that their performance will be 100% equal to conventional products,” he says. “There is going to be a long, slow process before anything like that comes to market with OEM approval.”

Andrew Richardson, global marketing director for AkzoNobel Aerospace Coatings in the U.K., explains that salt spray, filiform corrosion and alternate immersion testing are typical examples of aircraft OEM testing of aviation primers. “Primers do not necessarily have to pass all three tests under all OEM specs. Sometimes they do pass all three, but more often it’s two. The exact requirement is defined in each individual OEM spec,” he says. “The challenge for the industry is to find something that does as well as chromates in all three areas of testing.”

As a replacement for chromates, AkzoNobel has developed a magnesium-based primer known as Aerodur 2100 MgRP that has displayed what Richardson calls “excellent results” based on U.S. military testing. “In some cases, we have actually seen the performance of this primer exceed those using chromates. The next step will be to introduce it to the civil aircraft market.”

Richardson reports that water-based structural primers, such as the one available under the company’s Aerowave product line—which also includes water-based paints—are now commonplace at MROs and OEMs. “The VOC [volatile organic compound] levels are as low as 200 to 250g/L (grams per liter) instead of over 600g/L for conventional primers. Curing also takes less energy and helps reduce the carbon footprints of the painting system.”

Still, Richardson stresses, chromate-free products are just one factor in the aircraft painting equation.

“The aircraft OEMs are also looking for quicker throughput in their paint hangers, since they’re being driven to increase production rates, and it’s cheaper for them to look at faster drying paints as opposed to building new hangars to meet the throughput demand. And we expect that to filter down to the MROs as they get busier. At the same time, the airline customer wants the paint to stay on the aircraft longer. Lower weight in paint systems is also in demand due to increasing fuel costs.”

Sherwin-Williams’ Taylor notes that the trend toward faster drying products is, in large part, due to the highly customized, multi-color liveries that more airlines want. “Sherman-Williams has developed faster drying paints that enable the application of a multi-colored livery within a single shift rather than over a 3-4 day period.” As an example, the manufacturer introduced its Jet Glo Express exterior painting system to the air transport market in March 2002.

New clear coats, which are applied as a final layer over the completed paint job, provide improved ultraviolet protection and extended durability, says Taylor. In October 2010, Sherwin-Williams launched SKYscapes, a base coat/clear coat system, for commercial operators.

“The application of separate base coats and clear coats has been standard in the automotive industry but began to make its way into aerospace products just within the past 2-3 years,” Taylor says. “It is this base coat/clear coat process that extends the life of the paint.”

Sherwin-Williams, Taylor explains, began working on base coat/clear coat paint systems for aviation starting in 2008. “It was the economy that encouraged this, because the clear coat not only assures longevity, but provides easier, less costly maintenance of the finish.”

And, according to Taylor, the latest formulas provide airlines with a business jet-quality appearance. “There has been an improvement in the overall appearance and gloss, which has raised the bar with respect to customer expectations,” he says. “It will become the new norm in airliner painting.”

AkzoNobel’s Richardson echoes the claim that base coat/clear coat applications offer greater durability—something he says the company has been proving in tests on an in-service aircraft over the past 10 years.

“Over that time, we’ve found that the aircraft’s clear coat has maintained 90 gloss units of appearance—as measured by a 60-degree gloss meter,” Richardson states. “That is the same number of gloss units that an airframe OEM expects to have on an aircraft when it leaves the factory. Keep in mind, it’s very rare today for an aircraft to fly more than five years in its original livery.”

Karl Anderson, COO of Texas-based Dean Baldwin Painting, an aircraft painting company with a full service facility at Roswell, N.M., and a second one scheduled to open later this year near Indianapolis, reports that the base coat/clear coat approach should save on downtime as well as weight because fewer top coats are applied. “The paint manufacturers are marketing it very aggressively to the airlines in order to get this new paint process approved, since the airlines typically make the decision regarding the paint manufacturer and process used,” he says. “Once the airlines give approval, they will then tell the paint shops to include it in the quote requests.”

According to Anderson, the painting business shows signs of an upturn. “Two years ago, there were postponements of jobs that were already booked,” he says. “This year, we’re seeing many of those jobs come back and adding new customers.”

He attributes this in part to merger and acquisition activity resulting in new liveries, along with the fact that some aircraft are now past due for paint jobs.

“Painting is normally done on a five to six year cycle, and we are seeing some aircraft that have not been repainted for as long as seven to nine years,” Anderson says. “In fact, some airlines are increasing their fleet audits to determine which aircraft need painting the most, and those that do are coming in first.”

Widdershoven agrees. In fact, he points out that until about three or four years ago, the airlines simply wanted their aircraft painted. “Now, they want a high-gloss finish and are much more demanding as to the quality of the job,” he says. “To a large extent, this is being driven by the emergence of smaller airline companies that want to stand out from the crowd. They understand that if the aircraft looks good, the flying public perceives that it must be a good aircraft. We have customers bringing in airplanes as many as 25 years old and telling us to make them look factory-new.”

John Finnegan, aerospace division manager for Wisconsin-based Global Finishing Solutions—a leading industrial and aviation paint booth manufacturer—also reports signs of a recovery in the aircraft painting market as more MROs ramp up. “We really hit bottom in mid-2010, but now we’re getting an increasing number of inquiries for our products from MROs.”

Finnegan says that in 2010, independent aviation MROs accounted for about 27% of the company’s aerospace division. He expects that to reach 35-38% this year, with international markets emerging as the leading purchasers. “For every inquiry we get from a North American MRO, we’re getting two from outside the U.S.”

According to Finnegan, because more MROs are looking for ways to conserve energy, demand is growing for the most efficient products.

“Green technology is really the biggest push we’re seeing right now, and within that, specifically, is energy usage,” he says. “A paint booth uses more electricity than any other system at an MRO, and with energy being a major issue, more MROs are considering replacing their current paint booths with those that consume less energy. In addition, the energy-saving technology must still deliver the faster drying times that the MROs are asking for today.”