Static electricity is a complex science with a simple explanation: opposites attract. This principle has been applied to painting in the form of electrostatic paint guns. An electrostatic paint gun allows painters to apply an even, smooth and strong coat of paint with little overspray and minimal wasted paint.
Static electricity is a force created when the atoms of an object have an electrical charge. This charge is caused by an unequal number of protons and electrons. If more protons are present than electrons, the atoms will have a positive charge. If the number of electrons is greater, the atoms will have a negative charge. As with magnets, oppositely charged atoms will attract one another. Also, according to "Physics Classroom," a neutral atom -- one with an equal number of protons and electrons -- will be attracted to any charged particle, whether positive or negative.
Electrostatic Paint Guns
According to Spraytec, electrostatic paint guns work by creating a field of charged particles in the path of the paint exiting the gun. When paint particles are sprayed through the field at a high velocity, they carry charged particles with them. The charged particles and paint remain together and attempt to find and bond to a neutral surface capable of attracting and absorbing the charge, most commonly a bare metal. Other surfaces, such as wood, can be painted with the use of a grounding kit to make the wood act as a ground.
The charge given to paint by the electrostatic paint gun cause particles to distribute evenly and adhere strongly to surfaces. Because the particles are attracted directly to a surface, paint will seek out and adhere to the closest bare surface possible and pass by any areas already covered with paint, providing a uniform coverage. This also reduces over-spray and allows paint to wrap around surfaces. For example, when spraying a round pole, particles that miss the front of the pole will attach to the sides and back of the surface, allowing the entire pole to be painted with one sweep.
Electrostatic paint guns do not work efficiently with ungrounded or non-conductive materials. Although the paint gun will spray onto a surface without static electricity, the benefits of the electrostatic gun will not be present. A painter expecting electrostatic painting but using a poor surface will experience uneven coating and buildup. Painting on a flat surface with rigid edges, even on the best of materials, may result in thicker buildup of paint near the edges than on the rest of the surface. If the surface has a charge or is non-conductive, the painter may end up being the closest grounded surface, causing paint to find and adhere to skin where possible.
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