Abstract: Method of making a mask assembly by providing a heat resistance mask substrate having an exposed surface with a surface smoothness less than 2000 micro inches, uniformly spraying a thermoset epoxy organic coating onto such exposed surface in one or more layers to provide a coating having (e.g., a thickness equal to or less than about 0.005 inches), a smoothness characterized by an average profilometer reading (Ra) of no greater than 1.5 micrometers, said coating being devoid of pores that exceed about 0003 inch in size, and flame polishing all or a portion of such coating to effect a surface finish of about 1.0 micrometers. A mask assembly which is useful in masking areas from thermal spray particles, comprising a heat resistance substrate presenting an exposed grit blasted surface having a smoothness of less than 2000, and a thin thermoset epoxy coating bonded to said exposed surface and having a surface smoothness characterized by an average profilometer reading (Ra) no greater than 1.5.

Abstract: A method of fluxing a cast light-weight metal substrate for thermally adhering sprayed metallic coatings thereto, comprising: (a) preparing the substrate to be clean of grease and oil and to have a uniform and homogeneous surface energy; (b) electrostatically depositing a dry flux powder coating onto such prepared surface; and (c) thermally depositing melted metal onto and across the flux coated surface to further thermally activate the flux if not already activated, for stripping away any substrate oxides and to thermally metallurgically bond the deposited molten metal to the substrate.

Abstract: A method of thermally spraying at least one adherent metallic coating onto an unroughened cleansed aluminum or aluminum alloy substrate to produce a coated substrate, comprising: wire-arc thermally spraying of melted metallic bonding droplets and fluxing particles onto the substrate using air propulsion to concurrently adherently deposit flux particles and bonding droplets, the spraying using air propulsion and a wire feedstock having a core and a sheath, the wire core being constituted of both metal powder readily metallurgically bondable to the substrate and a fluxing powder that readily deoxidizes the substrate, the wire sheath being constituted of pliable metal that is metallurgically compatible with the core metal powder, the fluxing powder having a halide salt chemistry effective to deoxidize the substrate upon contact of the melted fluxing powder therewith, said fluxing powder and bonding metal having a particle size that more uniformly promotes distribution throughout said spray.