The spray booth is the center ring in what is often the three-ring circus of collision repair. The vehicle has been aligned, the body repaired by expert metal technicians, and now it’s prepped and ready for the finishing touch—the step that will make or break the job—the paint. It’s here in the paint booth that the magic happens: the color and the clear will be sprayed onto the car by a skilled technician, and the finish will be baked to a hard, shiny brightness that will, hopefully, dazzle the customer.
So it’s a no-brainer that maintaining the booth should be a top priority with every shop owner or manager.
All spray booths are engineered and installed to conform to the safety regulations of the Occupational Safety & Health Administration (OSHA) and the National Fire Protection Association, as well as local code requirements. After installation, however, compliance with all requirements becomes the responsibility of the shop owner.
Safety first
Safety is a primary consideration in booth maintenance. Remember, in the spray booth, a flammable liquid (paint) is being atomized. That means the potential for fire is a constant presence.
Experts agree that filters are the most important aspect of booth maintenance and often the most overlooked. In the heat of doing spot repair after spot repair, a shop may forget to change filters. Says a manager for a leading booth and oven manufacturer: “Sometimes a shop will let it go until the filter loads up and creates problems, like dirt on the job they’re repairing.”
Paint arrestor filters, which capture overspray, should be changed at least monthly and preferably semi-monthly.
This schedule can vary, depending on several factors, including the following:
- Type of spray system (HVLP, airless, higher or lower air pressure).
- Volume of material sprayed each day.
- Outside atmosphere—presence of contaminants, such as pollen, road dust, etc.
- Materials sprayed (high-density materials produce less overspray)
Most booth manufacturers base their filter replacement recommendations on the number of hours the filters are in use. In order to set up a schedule for your shop, you need to record spraying hours on a weekly basis during a one- or two-month period then determine the weekly average.
To maintain filters properly, keep the following points in mind:
Avoid getting ceiling filters wet with a hose. The pressure disturbs the fibers and allows the filter to pass fine dust.
Don’t operate an extraction unit without filters in place. Missing filters allow the fan to collect all the overspray and this eventually will diminish the airflow.
Don’t blow off the filter surface to try to extend filter life. Instead, change the filters regularly.
If your distributor recommends an alternative type of pre-filter or exit filter because it might offer longer life or greater efficiency, check with the booth manufacturer before choosing another type of filter. Filters must meet designed airflow levels to operate the spray booth properly. Check booth pressure and adjust it for each vehicle, if necessary.
Usually, exhaust filters need to be changed at 50- to 100-hour intervals. Note: When these filters are changed, the cabin floor grates must be thoroughly cleaned. (See sidebar, “The 1,000-hour interval” for more information about suggested maintenance for every 1,000 hours of use.)
The motors on most modern spray booths are self-lubricating. If not, the motor will have Zerk grease fittings. If so, lubricate the motor with good-quality grease.
The heating plant, if it is gas-fired, should require little or no maintenance. Oil burners should be inspected by a qualified service technician.
The overlooked fan motor
Filters get most of the attention when it comes to maintenance, as they should. However, the fan motor is often overlooked, according to a sales rep for another booth manufacturer. “I’ve seen fan motor belts that were within a thread of failing,” he says. “These belts need to be inspected every three-to-six months and should be replaced routinely once a year. They tend to glaze and harden, which makes them slip. That results in loss of airflow.”
Be careful to use the proper replacement belt, he warns. “Sometimes a shop will substitute an automotive belt, and that just isn’t going to work for any length of time.”
In a heated air-makeup booth, combustion blowers and burners are two other items that are often overlooked. It is here that body filler dust in the motor is one of the major culprits. Have a serviceperson take it apart and clean it.
It should go without saying that any maintenance operation must be done only when the booth is shut down. Make sure the main switch on the booth control panel is “off” and locked in such a way that the power cannot be turned on. And remember that some parts of the booth, particularly parts of the generator, will get hot during operation. Before doing any maintenance operation, it’s a good idea to make sure that all parts of the equipment have cooled down.
Also, keep in mind that the booth is designed for applying paint finishes and curing those finishes. It’s really not meant for prepping of any kind, other than masking and final tack-off, although many shops use it for prepping. And never sand in the booth. Sanding dust is anathema to the clean environment you are trying to maintain.
Clean painter, clean booth
Access to the booth should be limited only to the painters, who should change into their painting clothes inside the booth. And they should wear a lint-free “shoot suit.” Aside from wearing the suit only inside the spray booth, mixing room or booth vestibule, the painter should store it in an airtight plastic bag. And don’t open both doors unless the booth is operating.
On a daily basis, sweep the floor while the booth is in operation, unless it’s a completely grated floor. After each job, the floor should be vacuumed. Don’t clean the floor with water and a wet mop or squeegee. When the water dries, the dust will still be there. Besides, water mixed with dried paint overspray equals contaminated water, which can’t go down a sewer. If you have a central vacuum system, install a vacuum drop into your booth.
To facilitate the cleaning process, some shops opt for spray booth coatings that can be stripped or washed off once overspray and dirt has accumulated. Some of these coatings are white, which aids illumination. Avoid storing anything in the booth. Nothing should be in there except the vehicle, the painter, a spray gun and air hoses.
Keep air hoses to a minimum length. Long air hoses that drag on the floor spread dust and dirt. The best way to minimize hose length is to install an air drop on each side wall of the booth with a quick disconnect, filter and regulator. When the painter moves to the opposite side of the vehicle, he or she simply disconnects the air hose and re-connects on the other side.
Also, don’t allow duster guns in the booth. In fact, don’t allow any duster guns in your shop. When you need to remove dust, use a tack rag or vacuum. Duster guns simply put dust back into the air, while your goal is to remove all dust.
General cleaning
To clean both internal and external walls of your booth, use a soft, dry cloth. If the surfaces are extremely dirty, use a soft cloth dipped in a soap-and-water solution or a weak detergent solution. Wring out the cloth before wiping the surface. Wipe again with a soft, dry cloth.
Never use alcohol, paint thinner, benzene or a chemically treated cloth to clean the booth. They may damage the finish or your unit. Never pressure-wash or hose down the interior or exterior of the booth. Electrical shorts or shocks may result, and water can collect in light fixtures and various components of the booth cabin, causing rust. Pressure washing also could void the warranty.
In general, cleanliness is indeed next to godliness. And because of the environment in which the booth is located, it takes constant vigilance to maintain.
