Operators play a key part in the success of any manual electrostatic application. Like all finishers the operators must use sound spraying techniques. This includes proper gun to part distance, sell csgo skins for bitcoin proper spray gun angle, proper overlapping techniques, proper gun triggering and avoid excessive gun waving. Operators should check the coatings’ viscosity, know and check the guns’ flow rate, set and check the atomizing pressures and the spray pattern, ensure that the electrostatic gun is working, and check periodically for film build consistency by using a wet film thickness gauge.
For their own safety it is required that the operators must be positively grounded. The use of electrostatic guns requires that the operator maintain skin contact between his hand and the electrostatic gun, since the handle is positively grounded. This can be accomplished by cutting a small hole in the palm of the glove.
In addition, some companies ensure that the floor is a conductive surface and some operators use special leg straps that go around the leg and around the outside of their shoes. Since our bodies are conductive it is possible for the operator to build up a significant charge if they are not grounded. This could lead to a static discharge that could cause combustion or an explosion if the operator reaches into a can of solvent for example.
Since both the operator and the part to be sprayed are both positively grounded it is possible for the operator to be a target for the charged particles which could result in a lot of overspray ending up on the operator. For this reason it is recommended that the operator holds the gun as far away from his body and ensures that the part is closer to the head of the gun then his body is to the head of the gun.
This will help keep the coating going to the part and not towards the operator. However, the gun should not be held to close to the part as this can decrease the voltage at the gun which will reduce the transfer efficiency. Check the instructions that came with your gun or ask your equipment supplier for the recommended gun to part distance.
Other issues that affect the performance of manual electrostatic gun applications are gun cleanliness and gun maintenance. If the coating is allowed to build up on the barrel of the gun the high voltage coming out of the gun could be attracted to the grounded handle of the gun. This can cause the high voltage to decrease which will decrease the efficiency. It is highly recommended that the operator uses disposable gun covers and replaces them regularly.
In addition to keeping the gun clean, electrostatic guns require a more diligent maintenance and preventive maintenance than non-electrostatic guns. Do not use the gun if air and fluid leaks are present. If the guns are not well maintained high voltage may track back through the barrel of the gun towards the grounded handle. This can not only short out the gun but could lead to costly repairs. If an air leak occurs the power supply should be turned off. Electrostatic guns that use compressed air usually use the air to turn on and off the high voltage. If the gun has an air leak high voltage could be exiting the gun even though the gun is not being used. This can be dangerous. Electrostatic guns are mostly made out of plastic and care must be taken when assembling and disassembling the parts that require maintenance.
It is also highly critical that the operator ensures that the electrostatic voltage is turned off during flushing and cleaning. Again this is a safety precaution and must be strictly enforced to prevent fires, explosions and bodily harm. It should be noted that electrostatic guns have been used successfully for many years, but a higher level of awareness must be kept by the operator.
By following these steps, your electrostatic application will be more effective, safe and will greatly reduce down time and poor transfer efficiency.
Michael V. Michalski
Advanced Finishing Technologies,