Product Focus: Watching Paint Dry

Painting aircraft is possibly the most feared, most avoided and most time-intensive endeavor any human being can attempt. It is not only difficult and time-consuming, it often yields mixed results. State-of-the-art facilities, equipment and coatings can help.

Thank goodness there are people out there who are not only willing to paint things, but are also really good at it. Some of them find their way to the major aircraft manufacturers and MROs, where they practice their craft in facilities that are nothing short of technical marvels. AgustaWestland has such people, as well as a technologically advanced facility at its northeast Philadelphia plant.

Agusta builds about a dozen different models of helicopters, but only three in Philadelphia: the A119 light single-turbine, the A109 light twin-turbine and the AB/AW139 intermediate twin-turbine. Each aircraft is painted in the company’s new, state-of-the-art paint chamber; an area that was designed to meet strict environmental regulations, as much as it was designed to make new aircraft look great.

Step through the tall doors at the end of the $6.8-million, 40,000-square-foot assembly building, and you enter a cavernous, brightly lit Super Discovery Booth chamber built by SAICO of Arezzo, Italy. The work area is saturated with cool, white light from 740 florescent bulbs across the walls and ceiling. A second set of full-length accordion doors, similar to those leading into the space, separate the large front chamber from a second, slightly smaller one directly behind.

Protecting the Environment and Themselves

"The front can hold two aircraft side by side," advised Gordon Leathead, Agusta’s director of completions and maintenance at the Philadelphia location. (Of course, that’s with the main rotor blades off.) "Usually, there is only one aircraft in at a time."

Just outside two small side doors to the chamber are three 40-foot-tall, shiny sheet metal ventilating units; two for the larger main painting area and one for the smaller second booth. Their internal blowers draw air in from the outside and pump it up to discharge vents in the ceiling of the paint chambers. A second set of blowers creates a very noticeable downdraft that pulls the air down through floor gates, and out of the building, providing a quick exit for fumes and excess material from the paint sprayer.

But, ventilation isn’t the only job the massive blowers perform. Their primary purpose is to provide a painting area that exceeds a strict set of Environmental Protection Agency (EPA) safety standards laid down to reduce the amount of volatile organic compounds (VOCs) released into the air.

VOCs are emitted as gases from a variety of sources, such as lacquers, paints, thinners and certain cleaning supplies. When ingested, inhaled or absorbed by humans, these carcinogens can cause damage to vital organs. In high enough doses, contamination can even lead to death.

By 2002, the EPA had imposed guidelines that called for strict control over the isolation and recovery of VOCs to rid them from the atmosphere. While personal respirators prevent breathing-in the chemicals being used, they do not prevent absorption through the skin or their release into the air. So, next to keeping source chemicals sealed in their original containers, the best way to control VOCs is by extracting them from the air almost as quickly as they are released.

The ventilation system used by SAICO for their paint booths employs six groups of filters that capture dirt and contaminants throughout the airstream’s journey, from initial intake to final discharge back into the outside environment. The filters are then replaced in accordance with a vigorous retirement schedule.

This high-tech air handling system is not just for the painting chambers, though. Since stored chemicals, application devices and other supplies can release VOCs, Agusta’s paint mixing room, which doubles as a clean-up room, is also tied into the ventilation system.

At any given time, the mixing room can hold gallons of solvents and waste products from painting operations, all of which can release VOCs into the air. When closed up, dangerous levels of fumes can develop, attacking the first person who enters the room after several hours, let alone overnight.

As a safety measure, if a technician tries to enter the room after it has been closed-up long enough for VOCs to build, the air handling system will disable the lights inside of the room; a signal that it is not yet safe to enter. The blowers will then come on for three minutes, evacuating any harmful fumes. Once the room has been properly ventilated, the lights will automatically come on.

Of course, winters can be rather harsh in Pennsylvania, so Agusta’s paint chamber is heated; not just because aircraft paint needs to cure at warmer temperatures, but because the technicians don’t want to freeze while working. Just ask Dave Pennie and his partner, Rich Asterito. Between them, they have more than 50 years experience painting everything from automobiles to aircraft.

"It has a gas-fired heater for the winter," said Asterito as he scanned the ductwork. "I hear it’s a two million BTU system."

"You can get air conditioning," added Pennie. "We didn’t get it, though. It would be too expensive to try to cool all of this."

Painting with Flare

As with most technicians — artists, in this case — Pennie and Asterito are proud of their craft and the tools of their trade. There weren’t any helicopters ready for paint the day AM visited Agusta, but Pennie was eager to show-off one of the paint guns they use.

Called a "pressure pot" by those in the business, the DeVilbiss pressure spray gun draws the material from a hand-carried paint reservoir. It is then atomized on a 25-60 psi stream of air. According to Asterito, this system is better than conventional gravity-fed methods because it allows paint to be shot at any angle, including upside down. The reservoir, which is larger and easier to wield than the cups mounted atop gravity-fed guns, holds enough paint to last 15-20 minutes without reloading, and is easier to carry.

"Painting is the easy part," proclaimed Pennie. "Prepping is the hard part. It’s 90 percent of the job."

By prepping, Pennie was talking about all of the preliminaries that go into the process of painting a brand new helicopter. He laid it out in steps.

First, painters — Agusta has six at the Philadelphia location — take the cowlings, cam locks, compartment doors and other hardware off the newly assembled aircraft. This is done so they can paint around the edges where those items will be seated when reinstalled, giving the job a more seamless look.

Next, they mask places where paint isn’t wanted, either for mechanical or aesthetic reasons. The aircraft’s interior is also covered, with special attention going to the instrument panel and its debris-sensitive components. With paint being applied to the inside of door jambs, the possibility of getting overspray on interior appointments is an ever-present problem.

With all masking done, the next step is to turn on the chamber’s blowers and begin repairing small imperfections in the helicopter’s body, such as dents, chips and scrapes. This can require a lot of sanding.

A sealer is then applied, usually one, medium-wet coat that can also serve as a base coat for a one-color paint job.

Once the sealer has dried, it’s time to apply paint, most of which comes from DuPont’s Imron line or Sherwin Williams’ Acry Glo family of aircraft finishes.

The "recipes" for various colors require base shades to be mixed with specific amounts of pigments in order to achieve a particular shade of any given color. This can be done at the aircraft manufacturer’s level, but tends to be very time consuming and requires expensive computerized measuring gear. But, the advantage to in-house blending is that exact amounts of paint can be mixed as needed onsite, eliminating the cost of buying an entire gallon for $150 to $200 when only a quart is needed for a small job.

For now, Agusta chooses to order premixed paint as needed, and store whatever is left in their climate-controlled paint room for two to three years, in case something needs a touch-up in the future. The only onsite mixing they do is with paint additives, such as thinners and hardeners.

With personal respirators and other protective gear on, painters apply the requested colors to new aircraft.

"It takes four to five gallons of paint for one color on [an AW139]," said Asterito. "And that’s for two coats." For customers who want a more vivid sheen, a layer of clear coat can be applied afterwards.

Finishing Touches

Once the new paint finish has been allowed to cure for two hours, the aircraft is reassembled so that additional colors, such as stripes, lettering and N numbers, can be laid out and masked off. The affected components are then taken off once more. The areas that will be getting additional paint are prepared, painted, cured and returned to the airframe.

With the aircraft reassembled, the paint crew removes the masking and protective covers, and makes a final check for imperfections or overspray around the aircraft. All surfaces are then buffed to a high gloss.

Total man-hours for the entire job: 550-600 for their flagship AB/AW139 and 250-350 for the smaller A119 and A109.

Of course, the job isn’t finished until everything has been cleaned-up, so technicians carry their tools into the mixing room, where they use washers and chemical recovery systems made by Safety-Kleen of Plano, Texas. Solvents and other residual painting chemicals are then held in drums for proper disposal.

Yes, painting an aircraft is an arduous process, requiring specialized environmental safety precautions and tools, but one thing is for sure: There isn’t anything prettier than a shiny new helicopter with a fresh coat of paint.