The two entities that need to know where the overspray came from are the painting contractors that painted in the general area and the vehicle owners who
have had their vehicles covered with paint overspray.
One way to determine where the over spray came from is to look at surfaces such as signs, windows, fences and plants that are permanently positioned between the suspected source of the overspray and where the affected vehicles were parked . If the windows on a building are heavily covered on its east side, most likely the overspray came from the west. If a painter was painting on the west side of the building, he most likely is not responsible for the overspray.
Another factor to look at is the color and the density of the overspray particulates in a given area and their configuration pattern. If a painter had painted a green section of a nearby bridge, the overspray would be green unless it is the primer coat that has covered the vehicles. If the overspray appears to have covered a surface evenly with a mist, most likely the overspray was discharged from a paint gun. If the overspray pattern is unevenly dispersed and is sporadic on the vehicle surfaces with big and small overspray dots, the overspray most likely resulted from a painter rolling the paint on a structure. The wind currents having fanned the overspray droplets would leave this type of configuration.
If the overspray on a vehicle is behind the wheels and in the wheel wells, and on the bottom of a vehicle’s rocker panels, it most likely is the result of the vehicle having driven over a painted surface, such as painted lanes on a roadway. It obviously is not an airborne emission and wouldn’t have resulted from one painting a tall structure.
Another method of determining if an overspray incident is the fault of one paint source over another is for one to secure a comparative analysis by a reputable lab. Our company would take samples from a few vehicles from various sources where the overspray is thought to have originated, carefully document them, and then send them to a lab. When the samples are gathered they need to include the primer coat as well as the exterior coat from the suspected source of overspray. Documentation and custody control of the samples is extremely important especially if these samples are to be presented for use in a future legal proceeding. The lab would look at the samples microscopically and would run various chemical tests on them, with the results being placed on a graph to determine how likely they compare to each other.
If a water tower or a high span bridge or tall building has been painted as far away as a mile or more, a strong wind could have carried the overspray that far.
Often our company, with its forty-seven years experience, having handled thousands of overspray claims for insurance carriers and contractors all over the nation, is called in to help determine where the possible source of the overspray originated from. We do not charge for gathering overspray samples to be lab tested, if we are contracted to clean the over sprayed vehicles.