In powder flame spraying, the powdered spray additive is partly or completely melted in an oxy-acetylene flame and sprayed onto the surface of the workpiece by means of the expanding combustion gases. This thermal process significantly increases adhesion to the base material and the spray coating becomes impervious to both gas and liquid.
To accelerate the powder particles, an additional gas such as argon or nitrogen can be used. A wide variety of materials (far more than 100) can be used as additives.
In powder flame spraying, a distinction is drawn between self-flowing and self-adhesive flowing powder. Self-flowing powder usually requires additional thermal treatment. This "melting down" is usually done using oxy-fuel burners.