Guide to Electrostatic Painting
If you have file cabinets, elevator doors, or another type of metal surface that needs to be touched up, you need to go with electrostatic spray painting. Of course, before you hire someone to do a job, you want to know exactly what that job is. Take a minute to learn the basics about electrostatic spray painting so you will have a better understanding of how this process works. Then, you’ll be ready to dive in and get the job done.
The Law of Attraction
Have you ever taken your clothing out of the dryer, only to notice that a sock is stuck to the back of your sweater? This has to do with the law of attraction. Positively and negatively charged particles attract each other, which is why that sock sticks to that sweater. This same concept is used with electrostatic painting. The paint attracts to the metal, which makes it stick.
That’s a basic explanation. Let’s take a closer look at this.
The Electrostatic Spray Gun
The electrostatic spray gun plays an important role in electrostatic spray painting. Right before the paint shoots out of the nozzle, the gun gives it a positive charge. Then, the droplets shoot out of the gun and go through an electric field.
The grounded metal item that is being painted is negatively charged. The positively charged paint and negatively charged metal attract just like a magnet. This makes the paint stick on the metal surface.
For this process to work, it must utilize what is known as a corona discharge. This is the electrical discharge that occurs due to the ionization of the electrostatic spray paint as it hits the electric field that surrounds the metal. The corona might be gaseous, but since it contains free electrons, it is conductive.
The Electric Field
Now, let’s take a closer look at the electric field. It also has a big impact on the attraction that occurs between the paint and the metal. As soon as the electric field is created, the ions naturally flow along the field lines that take them to the metal’s surface. The ions cannot resist the force that the negatively charged metal creates. This attraction is 75 times stronger than the force of gravity, so it is easy to see why this method works so well. Because the force is so strong, the paint stays in place. The charge stays there long enough for the attraction to remain, meaning the paint stays on the metal. This reduces paint drift, which is why the transference rate with this process averages 98 percent.
Also, because the force of attraction is so strong, the paint droplets are pulled in multiple directions. That makes it easy to get all the sides of the metal object. Some of the particles will change direction midair to coat the top or the side of an object. This coating even manages to make its way into crevasses due to the strong pull.
Like Charges Repel Like Charges
This concept works because negative and positive attract. At the same time, like charges repel each other, which is why this paint doesn’t gather into huge drops. Instead, the paint remains as a fine mist, which works best for painting metal surfaces. That allows for an even coating all around the surface. The entire surface looks uniform and perfect.
Like Powder Coating, but Better
Due to the lack of overspray and large droplets, the result is a finish that closely resembles powder coating. It’s better than powder coating, though, since this system is portable. Powder coating is only available in factories, but a team can bring an electrostatic spray painting gun to your place of business and take care of the job onsite. Also, you do not have to worry about dismantling large metal items, since the paint can easily slip into crevices.
Spray Finishes offers electrostatic spray painting both onsite and in our factory. With offices in New York City, Connecticut, New Jersey, Long Island, and Westchester, we are right around the corner, ready to get to work. Contact us to find out more about how we can transform your old metal objects so they look like new.
*Content Updated: November 14, 2017