The purpose of the present paper is to describe a sequential method for studying the processes controlling the rate of layer deposition obtained by the projection of a powder conveyed by an airjet onto a hot surface. The first results obtained in a cold flow model study provide information on the hydrodynamics and settling conditions of the particles. Experimental results are compared with a theory describing the trajectories of the particles in wide practical domains. In a warm flow model, the heating conditions of the particles are then specified. A direct theoretical study is based on the use of the previously derived hydrodynamic model while a parallel indirect approach relies on the use of model particles of known physical and chemical properties. The good agreement between theory and experiments demonstrates the validity of the method.