Some paint operators assume electrostatic spray guns are out of reach for them, citing that they are too expensive and complex. Some are hesitant to invest in them, fearing they are unsafe.
Yes, electrostatic spray guns do cost more than air assist and legacy approaches, which can lead to initial sticker shock. However, the ROI in many applications and operations is easily calculated. Some people assume there will be huge changes in their processes and controls, but most of the standard operating procedures align with best practices for all paintwork.
Safety is a valid concern for your operators. The concept of electricity near paint scares a lot of people; they have heard stories about booths catching on fire. Electrostatic systems do generate more electrical charge, so you are increasing the risk. However when following proper procedures, electrostatic systems are safe and often include safety features such as automatic shutdown. Again, the safety precautions for electrostatic systems should be in place for all paint operations.
In this article, we will look at how electrostatic spray guns work, how most of their processes involve best practices you should be using in any paint operation, and how you can manage safety risks.
Electrostatic Sprayers’ High Transfer Efficiency Often Justifies Cost
The myth about the affordability of electrostatic spray guns is dispelled through the increased transfer efficiency. Electrostatic spray guns rely on the attraction of opposite electrical charges. The paint or coating is electrostatically charged as it passes through an electrostatic field produced between the electrode on the front of the gun and a grounded object. The charged particles of the material are attracted to the neutral, grounded object. The attraction is strong enough that the charged material will wrap itself around the object, which will increase the surface area that is coated.
Electrostatic guns have an excellent finish quality and a high transfer efficiency of up to 90 percent. The ROI for electrostatic sprayers is quickly realized in many applications and operations, as it is common to achieve a 30 percent increase in transfer efficiency.
Other benefits of using electrostatic spray guns include:
Cost savings from less material use, as more paint ends up on the part and less goes to waste.
Lower output of volatile organic compounds (VOCs), which means a healthier work environment for operators and helps with permitting fees and other environment, health, and safety (EHS) concerns.
Less clean-up, which also means reduced maintenance.
Safety Precautions Should be in Place for All Paint Work
The second common misconception about electrostatic sprayers is that they will require additional safety precautions. But most of the precautions are best practices for all paintwork.
For example, when using electrostatic sprayers, all components in the spray booth need to be properly grounded, and the booth and the sprayer need to be clean. But you are generating electrical charge anytime you are using a conventional spray gun, through the air and paint. And any time there is humidity in the air, you can build up static charge.
Think about how you generate static electricity on carpet in many residences – the shock you feel when reaching for a metal door knob.
Common static risks apply to discharge buckets, or a spark jumping to a booth wall. It is key to manage static electricity whenever you are painting. It’s a best practice to ground all objects (tables, hooks, grates, booth filters) to keep them from acting as capacitors.
Operator care and maintenance for electrostatic spray guns is different from air sprayers, as the plastic components require cleaning with a nylon brush as opposed to a wire brush. Electrostatic sprayers also require more sensitive handling, though you probably don’t want your operators dropping any spray gun from a ladder to the ground, sliding it across the floor, or leaving it in a bucket of solvent.
Safety Tips and Considerations for Paint Spray Operations
The key areas in the electrostatic painting process that must be grounded are the operator, the target, the air hose, and the paint supply. Test with a megohmmeter to ensure that there is a direct electrical path from the part that needs to be sprayed to the true earth ground. These areas are just the starting point for safety; experts at Spray Equipment & Service Center can help you ensure you have a safe and efficient operation.
OPERATOR: If the operator is not properly grounded, the paint can wrap back toward the operator or to the floor instead of being attracted to the target. Operators must be aware of safety precautions related to shoes, gloves, and the immediate work area.
TARGET: The object being painted is usually hung on hooks connected to a conveyor belt and grounded through its connection to the wall. It is important to keep hooks clean and avoid overspray, which can act as an insulator.
AIR HOSE AND PAINT SUPPLY: Be sure to use a specially grounded air hose; Graco hoses have left-handed threads to make sure you cannot connect the wrong air hose to the gun. Also ensure buckets and pumps are grounded, as are all components and objects in a mixing room.
Electrostatic Sprayers Require More Precautions for Waterborne Paint
Electrostatic sprayers are not the best solution for every material. For example, water more readily passes an electric charge, so electrostatic sprayers are not as efficient with
waterborne paint as with solvent-based paint. You may see a 10 percent improvement in transfer efficiency, so the benefits will be less. There also are differences in application, such as a Faraday cage effect in tight angles and corners. But operators can turn off electricity while using their electrostatic guns and rely on air spray.
Using an electrostatic sprayer to apply waterborne paint does require additional protection from a potential back-flow charge, so every component on that path must be isolated. You can use an indirect charge system to charge the paint after it has left the gun, but the transfer efficiency will decrease. You can also use an isolation system, such as the Graco Hydroshield spray packages.
Additional safety equipment is available for electrostatic sprayers, such as a gun flush box, in which you can flush a gun without touching it.
Work With Spray Equipment & Service Center for Electrostatic Gun Needs
Experts at Spray Equipment & Service Center can work with you to ensure you have the safest possible processes in place to gain the many benefits from using electrostatic spray guns. We also provide qualified technical support and added value through:
SOLUTIONS EXPERTISE: We listen and craft solutions to fit your unique business needs and goals.
RELATIONSHIP–FOCUSED APPROACH: We build trust by being responsive, meeting deadlines, and working hard to meet your highest expectations.
INDUSTRY LEADERSHIP: We have talented, experienced professionals at your service, here to keep your business as simple and profitable as possible.
We have the right equipment and parts in stock when you need them, and we are just a phone call away (866-953-0526). Put our experience, expertise, and approach to work for you at every stage of your business.