Abstract: A gas dynamic spray unit is provided that includes gun housing halves secured about a heater assembly. The heater assembly is retained within the gun housing using locating features provided on the heater assembly and the gun housing. An outlet fitting is secured to the heater assembly and supports a nozzle having a venturi that accelerates a carrier gas. The carrier gas is supplied to the nozzle by a passageway. A powder feed passage communicates with the nozzle to provide powdered material to the accelerated carrier gas, which is expelled from a tube. The passageway includes an aperture for leaking carrier gas inside the gun housing to pressurize the gun housing and prevent powdered material from infiltrating the gun housing. A shroud is secured to the gun housing about the tube to prevent damage to the tube and protect the user from contacting the hot nozzle and tube.