When converting an aircraft hangar into a paint hangar, it becomes more than a garage for your plane. It can be a complicated, expensive and time-consuming process. If successful, keeping contaminants out of paint jobs can still be difficult, and when heating and cooling systems are needed, operational costs are often high.
Another option to use your existing aircraft hangar space for painting is to install a paint booth insert. Adding a paint booth insert to an aircraft hangar is often simpler and quicker than converting a hangar into an environment suitable for spraying. Aside from the time savings, it also yields better airflow, cleaner air and better lighting. The end result is an improved environment for the painter, making it easier to do a high-quality paint job.
How to Convert an Aircraft Hangar into a Paint Hangar
Retrofitting an aircraft hangar for painting requires more than installing lighting and a filtration system. Code compliance must be achieved and heating and/or cooling systems may need to be added. Here is what is needed to convert an aircraft hangar into a paint hangar:
Electrical Wiring & Lighting
Any exposed electrical wiring and electrical outlets must be replaced or removed from an aircraft hangar when converting it into a paint hangar. New lighting and outlets must meet Class I, Division 1 requirements when located within the spray area — an area in which an ignitable concentration of flammable gas or vapors can exist under normal operating conditions. Lighting and outlets outside of the spray area but within 20 feet horizontally and 10 feet vertically must meet Class I, Division 2 requirements — suitable for a location in which flammable gases or vapors may be present in the air in sufficient quantities to be explosive or ignitable due to abnormal operation or occasionally transmitted from an adjacent Class I, Division 1 location.
Exhaust & Filtration
An exhaust plenum with filters and exhaust fans must be added to the hangar, in addition to exhaust ductwork. Exhaust filters must be in accordance with EPA Method 319. With a NESHAP-compliant three-stage filtration system, the first- and second-stage filters consisting of roll media and an MEPT panel filter (the less costly ones) protect the third-stage six-pocket bag filters (the more expensive ones) from paint overspray. This saves long-term maintenance costs by reducing the need to change out costly filters. A two-stage filtration system is sufficient for aircraft paint hangars if primers containing hexavalent chromium have been removed from the operation.
Containing contaminants from overspray is a high priority when primers with hexavalent chromium are used in a paint hangar. Exposure to hexavalent chromium can cause lung, nasal and sinus cancer, as well as eye, nose and throat irritation, nasal septum ulcerations, skin irritation, gastritis and ulcers.
Intake filters and filtered product doors also can be installed to reduce external contaminants. This helps keep dirt and debris from entering the paint hangar during the painting process.
Paint hangars can operate with opened or no doors and an exhaust system. For a cleaner environment, it may be necessary to filter the intake air and use an air make-up unit (AMU). Depending on the geographic location of the hangar, temperature and humidity control may also be needed. If the hangar is located in a hot climate, cooling will most likely be needed for the summer; likewise, heating is necessary for the winter in cold climates. Heating and cooling a paint hangar can be costly because there is no isolated space for the painting area that can reduce the volume of airflow required.
How Aircraft Paint Booth Inserts Compare to Paint Hangars
Aircraft paint booth inserts feature the engineering, design and construction of a paint booth, but can be easily placed inside a paint hangar. Aircraft paint booth inserts may be completely self-supporting, requiring only that the user bring in utilities and connect to the insert. Aircraft paint booth inserts have several advantages over converted paint hangars. External and process-related contamination control is easier with paint booth inserts. This, in combination with better lighting, can result in higher-quality paint jobs. The volume of airflow is also significantly reduced, which will decrease the costs for heating, cooling and air replacement.
To save money and construction materials, converted aircraft paint hangars sometimes have curtains covering the sidewalls, while the rafters are exposed. Leaving the rafters exposed creates multiple ledges and traps for dust and debris to accumulate — created by exposed beams, pendant-style lights and hanging ducts. Despite intake air being filtered through the AMU before entering the booth, small amounts of dust and debris will continue to fall into the paint hangar, contaminating paint jobs. In some paint hangars, the front door of the hangar is opened, and painting takes place with no AMU. Without an AMU, air still flows into the hangar’s exhaust chamber.
The air is cleaner in an aircraft paint booth insert because smooth walls and ceilings are provided (eliminating the need for curtains) and the rafters are covered. Smooth interior walls and surfaces are easier to clean, therefore making controlling overspray contamination easier. The opening in the hangar can be covered by bottom-rolling filter doors or plenum filter doors, both helping reduce external contaminants, such as dust and dirt.
Built-in lighting that is strategically placed in the ceiling and on the walls of paint booth inserts improves contrast, reduces shadows and gives painters increased visibility. Strategic placement of lighting is more challenging in paint hangars, especially with curtains on the walls, and the installation of lighting in paint hangars can be tricky and expensive.
Lights in paint hangars are typically expensive high-wattage HID lamps that drop from the ceiling and can be spread far apart to reduce costs. Strategically positioned four- to six-row T-8 fluorescent or LED light fixtures used in paint booth inserts not only provide a more luminous environment, they consume less energy.
With a paint booth insert, ceiling lights are only 7 or 8 feet above the fuselage, wings and tail sections. The optimized number of lights are arranged in a way that casts light onto the floor in strategic locations, allowing for reflectivity to the underside of the fuselage and wings. Sidewall lighting offers a highly visible surface at any point on the airplane, helping to increase contrast and reduce shadowing, which results in a better paint job.
Temperature & Humidity Control
Perhaps the biggest financial benefit of an aircraft paint booth insert compared to a paint hangar is the cost savings brought by better temperature and humidity control. Crossdraft and downdraft aircraft paint booth inserts can be constructed with conformal designs to accommodate the shape of the aircraft. Crossdraft paint booth inserts have higher ceilings over taller parts of the plane. Conformal designs decrease the cross-sectional area in the direction of the airflow, reducing the cubic feet per minute (CFM) of the overall airflow and allowing AMUs and fans to be reduced in capacity; this is unattainable in paint hangars due to the way they are constructed.
Rework is typically less with a paint booth insert due to the better external contamination control, improved lighting and more uniform airflow, leading to increased throughput. Depending on the size of the aircraft, rework can amount to several days of extra labor to repair defects in the coating. In addition to being unsightly, defects can be the origin site of new corrosion.
More than 10 code and standards organizations provide regulatory and standards guidance that governs the design of equipment for painting operations in aircraft paint hangars. Paint hangars must be compliant with NFPA 33, NFPA 409, OSHA 1910.94 and OSHA 1910.107. Since different locations may have varying code requirements, converting an aircraft hangar to meet your local authority’s standards for a paint hangar can be challenging. On the other hand, Global Finishing Solutions (GFS) aircraft paint booth inserts are designed to meet all applicable codes and standards that are widely accepted by national, state and local regulatory agencies.
“There are a lot of people who set up the bare minimum for an aircraft paint hangar and often regret it when the quality of the paint job suffers and rework is needed,” said Steve DellaSala, GFS aerospace and defense sales engineer. “Aircraft paint booth inserts from GFS are code-compliant and ideal for controlling contamination and maximizing finish quality.”
If you are contemplating the conversion of an aircraft hangar into a paint hangar, a paint booth insert should be considered as an excellent option. Overspray in paint hangars is harder to contain and clean, and a hazard zone can exist in the entire building if primers containing hexavalent chromium are present. With a paint booth insert, overspray is contained within the insert and can be more easily wiped down from smooth surfaces. Reduced external contamination and better lighting with an aircraft paint booth insert also can go a long way toward improving finish quality, and a conformal design from GFS can produce significant energy cost savings.