Why does the finish of my spray booth matter?
There are three common options for the surface finish of a spray booth’s walls, doors, etc. Choosing the correct finish can help in showing defects in the item being sprayed and seeing the actual finish applied to the item being coated.
Most spray booths are made with galvanized steel which is a zinc coating applied at the steel mill and results in a spackled gray finish that reduces corrosion (rust) on the metal. The finish has little reflectivity and will lessen as the finish darkens over several years of exposure. This is a very suitable choice for spray booths used to spray many colors including a high volume of white paint or powder coat.
Many spray booths are powder coated during the manufacturing process. This white or light gray durable finish adds a high degree of reflectivity to aid in increasing the light in a spray booth without actually adding lights. A powder coated spray booth used for powdercoating parts may also help in the process since the walls are less conductive than plan or galvanized steel. Powder coating a spray booth can be problematic with permitting in some locations; check with your local inspector before specifying this finish to your spray paint booth manufacturer.
The third option is to purchase a galvanized spray booth and to coat the interior walls with a spray-on booth coating like KATS as offered by ToolsUSA (item # 7905130). This material is easy to spray onto the booth interior and later remove once the overspray has built up to an undesired amount. Applying a new coating of KATS results in a like-new appearance in the spray booth interior.
OSHA 29.1910 and NFPA-33 have minimum requirements for air flow to decrease the concentration of flammable materials in a spray paint booth. The old standard was 100 linear feet per minute (lfm), and this is still stated in the International Fire Code (IFC). This air velocity is calculated with the spray paint booth empty and using a cross-sectional area of the air flow direction. The more current codes require a minimum of 4 air exchanges per minute for wet or solvent-based paints. Powdercoat booths are required to have 60 lfm.
Standard Tools uses 4 air exchanges to design our spray paint booths and uses the 100 lfm as a secondary reference. This can be a difficult task as a spray paint booth with 100 lfm when empty may be 150 lfm when a large auto or other obstacle is in the paint booth. This higher air flow can cause problems with the painting process. An appropriate sized spray paint booth should be ordered to prevent this from being a problem; requesting the spray booth too small can lead to painting issues that are difficult to overcome. Kelly can help you decide what size booth fits the needs of your body shop.
A concern of some new spray paint booth owners has been ‘my spray booth is a tornado’. Air velocity of 100 lfm calculates to 1.1 miles per hour. Comparing this to a normal walking pace of 3-4 miles per hour shows that no spray paint booth made by Tools USA is a tornado. The perception of air velocity can be amplified by the sound of the fan(s) and the noise of air flowing through steel ductwork.
The real issue with air flow in a spray paint booth is having adequate air. A 14’ wide x 9’ tall x 26’ long spray paint booth will exhaust at least 13,104 cubic feet of air per minute. Running this spray booth for twenty minutes requires 262,080 cubic feet of available air. This requires a building at least 17,472 sq ft with 15’ ceilings or 10,483 sq ft with 20’ ceilings. This issue of an undersized building can be addressed with booth design and/or an air make-up unit. Please contact Kelly at Standard Tools for more information.
Spray booths are generally made of steel. Due to the dramatic decrease in demand based on global markets, steel prices are as low as they have been for several years. Steel mills are reducing the amount of steel available on the market in order to increase prices as we go into 2010. Market specialists all agree that steel price will increase by 10-20% over the next six months. The price of paint booths will be affected by this increase.
You need time to install a booth and get it through the permitting process. In this slower economy most shops have time to get the spray booth installed and through the permitting process. The permitting process can take from a couple of days to months depending on your local inspectors and other factors. Also, most inspectors are more available now as construction levels are slower than normal.
Now is good time to start installing your spray booth so that you have it ready to use when your business level increases. To wait may mean getting that spray paint booth when you are too busy to install it and the inspectors are too busy to be easily available
What is ground-level ozone?
Ground level ozone refers to environmental standards regulated by your state pertaining to ozone emissions from your facility. Information about your state’s specific requirements and helpful hints are available by googling spray booth + ozone + (your state). Virginia has a very good page on this topic for Auto Body and Collision Repair Shops.
How do I comply with this requirement?
This requirement has little to do with the spray booth design and much to do with processes. Practices that reduce ozone emissions include:
– choosing paints and solvents with low VOC’s
– mixing as little paint as required
– cleanliness in storage of paint
– proper maintenance of your spray booth
– frequent changing of exhaust filters
– proper filters used that match material being sprayed
– proper and frequent elimination of used rags, cans, etc.
– proper training of employees using the equipment
There are several codes and regulatory standards that are used by various local governments for defining spray booth requirements. Each state, county and city usually selects one of these codes as the main top-level code to reference requirements. Some local governments will create their codes based on special requirements, but they often use one of the main standards as a guide.
NFPA-33 National Fire Protection Association’s Standard for Spray Application Using Flammable or Combustible Materials (current version is 2007). This is the most common code and does a very good job of defining how a spray booth is designed and constructed, air flow requirements and fire protection. This standard references many other lower level standards such as NEC (National Electric Code), NFPA-101 Life Safety code and NFPA-17 Dry Chemical Extinguishing Systems.
IFC International Fire Code – This international standard is a short and slightly modified version of NFPA-33. It does not have more or less stringent requirements than NFPA-33 but some requirements are included in sections outside of the spray booth chapter. This code is commonly used in areas of international trade zones.
IBC International Building Code – This code is similar to the IFC code but is rarely used at this time.
OSHA 29 CFR1910 Occupational Health and Safety Requirements – Each state has OSHA or NIOSH laws and codes that cover worker safety. Many states restate the federal codes. The chapters about spray booths often copy NFPA-33, but NFPA-33 is often revised before the federal OSHA code. The emphasis on the wording in this code is worker safety so there are more detailed requirements specific about ventilation.
Every spray booth constructed in the USA that is used in a workplace environment is required to comply with local OSHA codes so it is important for the spray booth users and owner to understand this code that is enforceable long after the booth is completed. A spray booth will be certified to the current NFPA, IFC or IBC code only when it is being constructed, but it must always comply with OSHA requirements.
NFPA-33 Standard for Spray Application of Flammable or Combustible Materials states:
Spray areas, which include by definition any associated exhaust plenums and exhaust ductwork, (and all associated equipment and areas) shall be protected with an approved automatic fire protection system.
This typically means that a spray booth will have a dry chemical system installed that:
– has automatically actuated ‘flags’ that set off the system if a fire develops in the booth, exhaust plenum, or exhaust ductwork
– has a audible alarm system if the system is actuated
– performs emergency shutdowns as required by the paint booth system design
– is designed and made by a certified manufacturer
– is installed by licensed contractors
– is inspected by a licensed inspector on a specified basis.
Most systems are solvent-based spray booths and powder coat spray booths are dry chemical units much like those used in restaurants. Some applications and localities may require wet sprinkler systems.
You should be able to find licensed contractors in your area, or you can call our sales or engineering staff for further help.
The following items are typical options to a spray booth. A description and factors about justification and costs are included for reference.
Modifying a standard design can dramatically increase the effectiveness of your spray paint booth and is usually due to the building restraints or vehicle/part/rack requirements. Many of the spray booths made by Tools USA have one, two or more of the following modifications.
1) Extra height
- Commonly one or two feet for a spray booth up to automotive size to allow for tall vehicles, parts or part racks.
- Over two feet often requires extra structural integrity (structural frames or beams).
- Adding to the height of a spray booth can require more total air to be exhausted to maintain linear air flow performance.
2) Extra length
- Standard panels of 24″, 34″ or 44″ width allow for longer vehicles, parts or racks, or more access around the item(s) being coated.
- Extra length in side-down draft spray booths may require more total fans to maintain safe air flow performance.
3) Extra lights
- Tools USA has designed our standard spray booths to have adequate lights and light placement for most applications.
- Extra lights can add to the total effectiveness of the booth for oddly shaped items or in the case of adding extra length to the spray booth.
- The standard lights (Class 2, Div II) are required by NFPA-33 to be no less than 36″ from any opening in the spray booth (doors, open-face, conveyor openings).
- See ‘Whitecoat’ below
4) Inside-access lights
- Inside-access lights are Class 1, Division II. These lights are used for three main reasons:
- The spray booth will be placed against a wall which limits the access for changing bulbs.
- The spray booth is to be designed with a light less than 36″ from a spray booth opening (door, open-face, conveyor cutout).
- The inside-access lights allow changing of bulbs from inside the spray booth.
- Inside-access lights require different mounting than standard lights so the entire panel has to be designed for this type of light.
- Inside-access lights are significantly more costly than standard lights.
5) White Powder Coat
- This process is a high-gloss, smooth white powder coat.
- This finish provides a high-gloss surface inside of the spray paint booth that reflects the illumination from the lights.
- This finish does not provide any more rust prevention than the galvanized finish on the standard wall panels.
- This finish does provide a more professional and detailed appearance.
6) Bi-fold doors
- Bi-fold doors are hinged in the middle.
- Bi-fold doors allow easier opening of the doors in a confined area.
- Bi-fold doors allow the weight of the open door to closer to the jamb and is the preferred design for doors over 65″ wide.
7) Tri-Fold doors
- Tri-fold doors are a bi-fold door and a single-wide door in place of two single-wide doors
- Tri-fold doors allow easy access to the spray booth.
8) Drive-thru doors
- Drive-thru doors allow the vehicle, part or part rack to pass through the spray booth. These are typically used in industrial situations where staging of parts is more typical.
- Drive-thru doors can affect the efficiency and overall height of the spray booth if the exhaust plenum has to be modified for height requirements of the door.
9) Rear exhaust
- This design allows the fan to be mounted on the back wall of the spray booth instead of the top.
- This design is most commonly used in low ceiling buildings or when a duct already exists for exhaust out of a wall.
10) Air Make-up Unit
- This unit allows air to be supplied to the intake of a spray booth either from the outside of the building (most common) or inside the building.
- The air temperature can be increased by up to 100-degree F (for most applications) to allow use of cold outside air and/or to expedite the flash-off and curing process.
- The units are costly but can dramatically increase the efficiency of the spraying and curing process.
11) HEPA Filter
- This filter unit allows exhausted air to be returned to inside of the building.
- This unit applies only to powder coating or media blasting operations.
- This unit does not apply to solvent-based or water-based spraying operations.
What is ETL?
ETL is an international third-party contractor that tests and verifies that products meets specific codes. NFPA-33 is the National Fire Prevention Agency’s Standard for Spray Application of Flammable or Combustible Materials. It is the nationally recognized code that defines the requirements for a spray booth and paint mixing room. Tools USA offers an optional ETL kit for a wide variety of paint booths that includes the recognized ETL label and the hardware that complies with the certification.
What does this kit do for the Customer?
Buying an ETL kit with the spray booth means that the booth will come with a label to signify to any inspector, fire marshal, or insurance agent that the paint booth or mixing room complies with NFPA-33. The materials, air flow, electrical components and functioning of the booth have been qualified by an experienced and certified expert for compliance to NFPA-33.
A major part of the kit is the electrical control panel which makes it easy to control the lights and fan, has built-in timers to purge the paint booth of vapors and has the proper magnetic starter matched to the fan and motor. It is a good investment for safe use of the paint booth and will extend the life of your booth.
Our most commonly purchased booths are included:
Many of these standard booths can be ETL-labeled with changes in size and other modifications. This kit is not available for booths that have been powdercoated.
SD-1000 (semi-down draft)
SDD-1000 (side-down draft)
OFB-1000 and IPW-1000 (open face booths)
MR-1000 (mixing room)
What does this ETL kit include?
This kit includes:
- ETL label
- Electrical control box (for lights and fan motor, includes 3-minute fan motor delay)
- Limit switch for each door
- RedHat solenoid valve
Contact us at:
STANDARD TOOLS & EQUIPMENT CO. 800-451-2425
TOOLS USA www.toolsusa.com
If you are in the market for a spray booth, then look no further! www.ToolsUSA.com
We are the leading manufacturer and direct seller of paint spray booths in the industry.
We manufacture all the paint booths we sell in our Greensboro N.C. facility.
Why is that important to know?
1. The first most obvious advantage to buying a paint booth from the manufacturer is a greater cost savings to you without sacrificing quality.
2. Second is the fact that, on top of our full line of standard sizes and styles of booths, we can customize any spray booth to meet your exact needs.
3. We truly believe that our experience, knowledge, and realistic pricing set us apart in today’s market place.
If you need a written quote, please don’t hesitate to call or e-mail us.