A primer for flame sprayed polyolefin comprises an epoxy resin, preferably of low molecular weight and/or low viscosity; and an amine hardener, part of which becomes highly reactive on exposure to open flame, providing near instant cure of the composition under flame spray conditions. The invention is unique that it provides strong adhesion to steel, even where the surface preparation is less than ideal, as well as to concrete and other substrates. The primer eliminates the need to preheat the substrate. The primer has strong adhesion to the topcoat polyolefinic material, especially to a functionalized topcoat. The composition withstands open flame and does not char under polyolefin flame spray conditions, nor does it run or sag, and it is not prone to failure as it cools after the application of the polyolefin.