In brief, the electrostatic spray coating technique typically involves a few basic steps:

1. Preheat a part or product
2. Electrically ground the product
3. Spray the product with negatively charged powdered resin with a specialized spray gun
4. Apply heat to cure the coating

While electrostatic spray coating and painting are similar techniques and the terms are sometimes used interchangeably, they feature two key differences:

• Material — Electrostatic spray (powder) coating uses powdered polymer resins while electrostatic spray painting uses a liquid paint.
• Process — Electrostatic spray (powder) coating must typically be heat cured, while electrostatic spray painting requires only drying time with no additional heating required.

Because of the incredibly strong electromagnetic bond formed between the coating and substrate, powder coating is exceptionally durable, resilient, and long lasting. Fast and cost-effective, it's an ideal solution to protect vulnerable metal.

Electrostatic powder coating is quite eco-friendly, requiring no volatile organic compounds (VOCs) or solvents to apply, and generally producing virtually no waste, including no hazardous waste. 

In general, any products which can safely tolerate the heat required are suitable for spray powder coating. Alternative methods, such as fluidized bed techniques, may produce better results for products with complex shapes or structures that may produce Faraday cage effects or create other barriers to complete coverage.