This process melts wire feedstock in a flame and atomizes it using compressed air to form fine droplets. The flame is fueled chemically (often acetylene with oxygen). Atomized molten material is propelled toward the substrate and solidifies rapidly to form a coating. Spray rates for stainless steel range from 0.5 to 9 kg/h (1 to 20 lb/h), with lower melting materials like zinc spraying at higher rates. Substrate temperatures are typically 95 to 205 °C due to flame energy input. Usually, under 10% of input energy melts the feedstock.