Depending on the type of blast media being used and the procedure, non-hazardous but uncomfortable static discharges can be felt in the blasting operator’s arms. This is caused by the flow of the media through the blast nozzle. A static charge is built up and eventually can charge the part being blasted. The friction of the abrasive against the part also builds up a charge.
If the part is lying on the steel work floor, the charge usually transfers to the ground through the metal cabinet. If the part is being held with the blasting gloves, the isolated charge build-up can travel through the gloves and charge the steel arm hole. The build-up can then arc from the arm hole to the operators arm.
The amount of static build-up will vary with different media types. Glass Bead tends to produce the most charge.
The next post will list a number of tips and suggestions to eliminate the static build-up and prevent shocking the operator.