a one - part composition for application to a substrate , e . g ., automotive metal body panels , to provide reinforcement thereto is a thixotropic admixture containing as essential components a heat curable epoxy resin system including the reaction product in the presence of a catalyst of at least one epoxy resin with a carboxy terminated elastomer , dicyandiamide , and a plurality of inorganic particulate filler materials , at least one of which is capable of imparting thixotropic properties to the composition . the method of reinforcing the substrate involves spraying the one - part epoxy resin containing composition onto at least a portion thereof in a heated condition and thereafter curing the composition at a temperature higher than the spraying temperature . resulting reinforced substrates have tenaciously adhered thereto on at least a portion of one surface thereof a thermoset layer formed by the hot spraying and then curing thereon of the thixotropic composition .