that the aliphatic low viscosity epoxy compounds give excellent results in this invention when used alone examples of this type of epoxy are the triglycidyl ester of trimethylol propane reichhold stf 6 aliphatic polyglycidyl ether celanese epi rez 5042 aliphatic triglycidyl ether celanese epi rez 5044 however inclusion of epoxy compounds containing aromasticity have been found to increase the toughness of the film and also to lower the overall cost of the epoxy component an example of an aromatic epoxy are the diglycidyl ethers of bis p p hydroxyphenyl propane shell epon 828 celanese epi rez 510 the non volatile polylol component d used as a reactive diluent performs the dual purpose of lowering the viscosity of the resin prior to cure and also improves the flexibility of the finished cured coating its volatility must be such that it will not volatize significantly at the curing temperature the hydroxy groups of this polyol must be of sufficient reactivity to allow condensation with either the epoxy or the phenolic components the amounts of this polyol needed depends on the flexibility of the phenolic and epoxy component selected and may vary from 3 25 weight percent representative polyols useful as component d in this invention are those shown in table 1 also shown in this table is the percentage remaining after heating the polyol at 400 u00b0 f for 10 minutes in an air circulating oven along with other property information table i__________________________________________________________________________ solids 10 min ohproduct at 400 u00b0 f value viscosity supplier__________________________________________________________________________pcp 0300 sup 1 92 310 14 5 stokes union carbide2 tmp 1 adipic polyester 80 7 568 440 stokes ashlandmiltron r 16 sup 2 87 0 44 104 1 stokes mobaymiltron r 18 sup 2.