A coherent material is formed on a substrate (10) by providing a precursor suspension (14) in which particulates are suspended in a carrier fluid, and directing the precursor suspension (14) at the substrate (10) from a first source (12). Generally contemporaneously with application of the deposited precursor suspension (14) to the surface, hot gases, e.g. hot gases produced by a flame (16), are directed at the substrate (10) from a remote second source (18) to fuse the particulates into the coherent material.