The powder flame spray technique closely resembles the combustion wire spray method, with the key difference being the use of powder instead of wire as the feedstock. In this process, the powder material is melted or partially melted by the heat generated from an oxyfuel flame, and the resulting molten particles are propelled toward the target surface by the expanding combustion gases and air jets. A carrier gas delivers the powder into the flame, where the gases then carry it to the pre-treated substrate. Common fuel gases used include acetylene and hydrogen.

In this setup, the powder is fed axially from the rear of the nozzle and enters the flame at the nozzle’s exit point. This configuration allows for a broader selection of coating materials compared to wire flame spraying.

The particle velocities are relatively low (under 100 m/s), which results in bond strengths that are generally less than those achieved with high-velocity techniques. Coatings often exhibit higher porosity and reduced internal cohesion. The spray rate typically falls between 0.5 and 9 kg/h (1 to 20 lb/h), although materials with lower melting points can be applied at faster rates. Due to the direct exposure to the flame, the surface temperature of the substrate can become quite high.