A.
The use of electrostatics on wood has been around for awhile. As a general overview, most industrial finishers use electrostatics when they are coating parts that are hard to spray evenly. Common applications would be cribs or bed ends where an electrostatic can coat the dowels evenly without the usual overspray seen on sprayed applications.
The wood is the negative pole so the coating carries the positive charge.
The drawbacks are that you are dealing with a very flammable combination of products...solvent based coatings, wood and electricity. Very specialized equipment and specific coatings are needed before this is a feasible method to use. It is also a system that requires excellent operator training and consistency to stay safe.
As to cost, once the equipment is set up, they are similar to other coatings, but the equipment cost is the biggest investment hurdle.
- See more at: http://www.woodweb.com/knowledge_base/Electrostatic_finishing_of_wood_products.html#sthash.1znhPuoQ.dpuf